To see the other types of publications on this topic, follow the link: 0D-1D simulation.
Journal articles on the topic '0D-1D simulation'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic '0D-1D simulation.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Simakov, Sergey S. "Spatially averaged haemodynamic models for different parts of cardiovascular system." Russian Journal of Numerical Analysis and Mathematical Modelling 35, no. 5 (2020): 285–94. http://dx.doi.org/10.1515/rnam-2020-0024.
Full textAbstract:
AbstractThis paper revisits the usage of spatially averaged haemodynamic models such as non-stationary 1D/0D in space and stationary 0D in space models. Conditions of equivalence between different 1D model formulations are considered. The impact of circular and elliptic shapes of the tube cross-section on the friction term and the tube law is analyzed. Finally, the relationship between 0D lumped and 1D models is revealed.
2
Alastruey, Jordi, Nan Xiao, Henry Fok, Tobias Schaeffter, and C. Alberto Figueroa. "On the impact of modelling assumptions in multi-scale, subject-specific models of aortic haemodynamics." Journal of The Royal Society Interface 13, no. 119 (2016): 20160073. http://dx.doi.org/10.1098/rsif.2016.0073.
Full textAbstract:
Simulation of haemodynamics has become increasingly popular within the research community. Irrespective of the modelling approach (zero-dimensional (0D), one-dimensional (1D) or three-dimensional (3D)), in vivo measurements are required to personalize the arterial geometry, material properties and boundary conditions of the computational model. Limitations in in vivo data acquisition often result in insufficient information to determine all model parameters and, hence, arbitrary modelling assumptions. Our goal was to minimize and understand the impact of modelling assumptions on the simulated blood pressure, flow and luminal area waveforms by studying a small region of the systemic vasculature—the upper aorta—and acquiring a rich array of non-invasive magnetic resonance imaging and tonometry data from a young healthy volunteer. We first investigated the effect of different modelling assumptions for boundary conditions and material parameters in a 1D/0D simulation framework. Strategies were implemented to mitigate the impact of inconsistencies in the in vivo data. Average relative errors smaller than 7% were achieved between simulated and in vivo waveforms. Similar results were obtained in a 3D/0D simulation framework using the same inflow and outflow boundary conditions and consistent geometrical and mechanical properties. We demonstrated that accurate subject-specific 1D/0D and 3D/0D models of aortic haemodynamics can be obtained using non-invasive clinical data while minimizing the number of arbitrary modelling decisions.
3
Zou, Wangzhi, Zhaoyun Song, Baotong Wang, Mengyang Wen, and Xinqian Zheng. "An efficient multi-fidelity simulation approach for performance prediction of adaptive cycle engines." Journal of the Global Power and Propulsion Society 8 (August 29, 2024): 310–22. http://dx.doi.org/10.33737/jgpps/191167.
Full textAbstract:
Adaptive cycle engine (ACE) with multi-stream, modulated bypass ratio, and high-thrust/high-efficiency mode provides the capability of multiple mission adaptation for the next-generation aviation propulsion system. The low-fidelity zero-dimensional (0D) performance simulation method is commonly adopted in conventional engines such as turbofan and turbojet. However, it is hard to accommodate well to ACE with complex variable geometry schemes and strong interaction between components. This paper presents an efficient multi-fidelity simulation approach, often referred to as component zooming, for predicting the performance of ACE with the three-stream configuration. The one-dimensional (1D) mean-line models of the adaptive fan and low-pressure turbine (LPT) are integrated into the 0D ACE model by the iteratively-coupled method. The performance predicted by the multi-fidelity ACE models with different component zooming strategies is compared. The maximum deviations of thrust, specific fuel consumption, turbine inlet temperature, and bypass ratio between the 0D/1D Adaptive Fan/1D LPT coupled model and 0D ACE model are −10.8%, −4.4%, −5.4% (−75 K), and 1.6%, respectively, which are considerable and non-negligible for the application in the design stage of ACE. The computing time of all the multi-fidelity models is less than 2 minutes. The effects of the key aerodynamic parameters of the adaptive fan and LPT on the engine performance are also evaluated. The proposed approach provides a generic and efficient solution for multi-fidelity ACE performance prediction with acceptable computing resource requirements and time cost, which is applicable in the engine conceptual and preliminary design stage.
4
Naidis, G. V., and N. Yu Babaeva. "Low-pressure CO2 discharges: 1D modeling." Physics of Plasmas 30, no. 1 (2023): 013506. http://dx.doi.org/10.1063/5.0130672.
Full textAbstract:
A 1D model of glow low-pressure CO2 discharges is developed. In the framework of this model, simulation of stationary and repetitively pulsed discharges at pressure ranging from 0.5 to 5 Torr and current from 10 to 50 mA is performed. The obtained plasma characteristics are compared with the available experimental results and with the data evaluated based on the approximate 0D approach. The results of 0D and 1D calculations agree for most of plasma parameters, except for the molar fraction of CO molecules produced at CO2 dissociation by electron impact. Agreement between the measured and calculated, in the framework of the 1D model, values of the CO molar fraction is provided by modifying the expression of the dissociation rate constant vs the reduced electric field.
5
Echeverribar, Isabel, Pablo Vallés, Juan Mairal, and Pilar García-Navarro. "Efficient Reservoir Modelling for Flood Regulation in the Ebro River (Spain)." Water 13, no. 22 (2021): 3160. http://dx.doi.org/10.3390/w13223160.
Full textAbstract:
The vast majority of reservoirs, although built for irrigation and water supply purposes, are also used as regulation tools during floods in river basins. Thus, the selection of the most suitable model when facing the simulation of a flood wave in a combination of river reach and reservoir is not direct and frequently some analysis of the proper system of equations and the number of solved flow velocity components is needed. In this work, a stretch of the Ebro River (Spain), which is the biggest river in Spain, is simulated solving the Shallow Water Equations (SWE). The simulation model covers the area of river between the city of Zaragoza and the Mequinenza dam. The domain encompasses 721.92 km2 with 221 km of river bed, of which the last 75 km belong to the Mequinenza reservoir. The results obtained from a one-dimensional (1D) model are validated comparing with those provided by a two-dimensional (2D) model based on the same numerical scheme and with measurements. The 1D modelling loses the detail of the floodplain, but nevertheless the computational consumption is much lower compared to the 2D model with a permissible loss of accuracy. Additionally, the particular nature of this reservoir might turn the 1D model into a more suitable option. An alternative technique is applied in order to model the reservoir globally by means of a volume balance (0D) model, coupled to the 1D model of the river (1D-0D model). The results obtained are similar to those provided by the full 1D model with an improvement on computational time. Finally, an automatic regulation is implemented by means of a Proportional-Integral-Derivative (PID) algorithm and tested in both the full 1D model and the 1D-0D model. The results show that the coupled model behaves correctly even when controlled by the automatic algorithm.
6
Chen, Yan, Masaharu Kobayashi, Changyoung Yuhn, and Marie Oshima. "Development of a 3D Vascular Network Visualization Platform for One-Dimensional Hemodynamic Simulation." Bioengineering 11, no. 4 (2024): 313. http://dx.doi.org/10.3390/bioengineering11040313.
Full textAbstract:
Recent advancements in computational performance and medical simulation technology have made significant strides, particularly in predictive diagnosis. This study focuses on the blood flow simulation reduced-order models, which provide swift and cost-effective solutions for complex vascular systems, positioning them as practical alternatives to 3D simulations in resource-limited medical settings. The paper introduces a visualization platform for patient-specific and image-based 1D–0D simulations. This platform covers the entire workflow, from modeling to dynamic 3D visualization of simulation results. Two case studies on, respectively, carotid stenosis and arterial remodeling demonstrate its utility in blood flow simulation applications.
7
Dilber, Viktor, Momir Sjerić, Rudolf Tomić, Josip Krajnović, Sara Ugrinić, and Darko Kozarac. "Optimization of Pre-Chamber Geometry and Operating Parameters in a Turbulent Jet Ignition Engine." Energies 15, no. 13 (2022): 4758. http://dx.doi.org/10.3390/en15134758.
Full textAbstract:
A turbulent jet ignition engine enables operation with lean mixtures, decreasing nitrogen oxide (NOX) emissions up to 92%, while the engine efficiency can be increased compared to conventional spark-ignition engines. The geometry of the pre-chamber and engine operating parameters play the most important role in the performance of turbulent jet ignition engines and, therefore, must be optimized. The initial experimental and 3D CFD results of a single-cylinder engine fueled by gasoline were used for the calibration of a 0D/1D simulation model. The 0D/1D simulation model was upgraded to capture the effects of multiple flame propagations, and the evolution of the turbulence level was described by the new K-k-ε turbulence model, which considers the strong turbulent jets occurring in the main chamber. The optimization of the pre-chamber volume, the orifice diameter, the injected fuel mass in the pre-chamber and the spark timing was made over 9 different operating points covering the variation in engine speed and load with the objective of minimizing the fuel consumption while avoiding knock. Two optimization methods using 0D/1D simulations were presented: an individual optimization method for each operating point and a simultaneous optimization method over 9 operating points. It was found that the optimal pre-chamber volume at each operating point was around 5% of the clearance volume, while the favorable orifice diameters depended on engine load, with optimal values around 2.5 mm and 1.2 mm at stoichiometric mixtures and lean mixtures, respectively. Simultaneous optimization of the pre-chamber geometry for all considered operating points resulted in a pre-chamber volume equal to 5.14% of the clearance volume and an orifice diameter of 1.1 mm.
8
YUHN, Changyoung, and Marie OSHIMA. "Effects of reducing 1D network complexity in a 1D–0D simulation of cerebral circulation." Proceedings of the Bioengineering Conference Annual Meeting of BED/JSME 2019.32 (2019): 1A22. http://dx.doi.org/10.1299/jsmebio.2019.32.1a22.
Full text
9
Kovács, László, and Szilárd Szabó. "Test validated 0D/1D engine model of a swinging valve internal combustion engine." Multidiszciplináris tudományok 11, no. 4 (2021): 266–77. http://dx.doi.org/10.35925/j.multi.2021.4.31.
Full textAbstract:
In the quest for reaching ever higher power density of IC engines a much simpler solution has been investigated that allows vehicles to reach a comparable power level with cars equipped with turbo charged engines. The new Swinging Valve (SwV) arrangement enables the unhindered gas exchange process through an engine. In this experiment a flow bench was used to examine a normal poppet valve cylinder head and a cylinder head constructed for the same engine but with Swinging Valves. The flow parameters of the original cylinder head were obtained then the SwV head was investigated in the same way. To examine the practical use of a SwV system a 0D/1D engine simulation had been created, first using the engine with conventional cylinder head. That model had been validated with dynamometer tests. After this stage the results of the Swinging Valve flow measurements were fed in the same 0D/1D engine simulation then the results were compared and examined.
10
Tretyakova, Rufina M., Gennady I. Lobov, and Gennady A. Bocharov. "Modelling lymph flow in the lymphatic system: from 0D to 1D spatial resolution." Mathematical Modelling of Natural Phenomena 13, no. 5 (2018): 45. http://dx.doi.org/10.1051/mmnp/2018044.
Full textAbstract:
In this study, we formulated a core mathematical model for describing the one-dimensional lymph flow in lymphatic vessels and branching network of lymphatic vessels. The 1D model was numerically implemented using the 1D haemodynamic modeling tools developed in T.M. Gamilov et al. and S. Simakov et al. [T.M. Gamilov et al., Transl. Med. 6 (2013) 5–13 and S. Simakov et al., Russian J. Numer. Anal. Math. Model. 28 (2013) 485–504]. The formulated model was calibrated using published data on lymph flow dynamics and other modelling studies of lymph flows. The comparison of 0D and 1D formulations of the lymph flow models is presented.
11
Katsoudas, Spyridon, Stavros Malatos, Anastasios Raptis, Miltiadis Matsagkas, Athanasios Giannoukas, and Michalis Xenos. "Blood Flow Simulation in Bifurcating Arteries: A Multiscale Approach After Fenestrated and Branched Endovascular Aneurysm Repair." Mathematics 13, no. 9 (2025): 1362. https://doi.org/10.3390/math13091362.
Full textAbstract:
Pathophysiological conditions in arteries, such as stenosis or aneurysms, have a great impact on blood flow dynamics enforcing the numerical study of such pathologies. Computational fluid dynamics (CFD) could provide the means for the calculation and interpretation of pressure and velocity fields, wall stresses, and important biomedical factors in such pathologies. Additionally, most of these pathological conditions are connected with geometric vessel changes. In this study, the numerical solution of the 2D flow in a branching artery and a multiscale model of 3D flow are presented utilizing CFD. In the 3D case, a multiscale approach (3D and 0D–1D) is pursued, in which a dynamically altered velocity parabolic profile is applied at the inlet of the geometry. The obtained waveforms are derived from a 0D–1D mathematical model of the entire arterial tree. The geometries of interest are patient-specific 3D reconstructed abdominal aortic aneurysms after fenestrated (FEVAR) and branched endovascular aneurysm repair (BEVAR). Critical hemodynamic parameters such as velocity, wall shear stress, time averaged wall shear stress, and local normalized helicity are presented, evaluated, and compared.
12
Dazzi, Susanna, Riccardo Verbeni, Paolo Mignosa, and Renato Vacondio. "Simulation of Flood-Control Reservoirs: Comparing Fully 2D and 0D–1D Models." Hydrology 11, no. 11 (2024): 180. http://dx.doi.org/10.3390/hydrology11110180.
Full textAbstract:
Flood-control reservoirs are often used as a structural measure to mitigate fluvial floods, and numerical models are a fundamental tool for assessing their effectiveness. This work aims to analyze the suitability of fully 2D shallow-water models to simulate these systems by adopting internal boundary conditions to describe hydraulic structures (i.e., dams) and by using a parallelized code to reduce the computational burden. The 2D results are also compared with the more established approach of coupling a 1D model for the river and a 0D model for the reservoir. Two test cases, including an in-stream reservoir and an off-stream basin, both located in Italy, are considered. Results show that the fully 2D model can effectively handle the simulation of a complex flood-control system. Moreover, compared with the 0D–1D model, it captures the velocity field and the filling/emptying process of the reservoir more realistically, especially for off-stream reservoirs. Conversely, when the basin is characterized by very limited flood dynamics, the two approaches provide similar results (maximum levels in the reservoir differ by less than 10 cm, and peak discharges by about 5%). Thanks to parallelization and the inclusion of internal boundary conditions, fully 2D models can be applied not only for local hydrodynamic analyses but also for river-scale studies, including flood-control reservoirs, with reasonable computational effort (i.e., ratios of physical to computational times on the order of 30–100).
13
Pappa, Alessio, and Ward De Paepe. "Humidification Towards Flashback Prevention in a Classical Micro Gas Turbine: Thermodynamic Performance Assessment." E3S Web of Conferences 414 (2023): 03010. http://dx.doi.org/10.1051/e3sconf/202341403010.
Full textAbstract:
Combustion air humidification has proven to be effective to stabilize hydrogen combustion and to avoid flashback apparition in a typical micro Gas Turbine (mGT). However, both the fuel alteration and combustion air dilution will impact the cycle performance. A complete characterization of this thermodynamic impact is essential to ensure that the mGTs become cleaner, and fully flexible to fit with the expectation of future small-scale decentralized power production. Therefore, the objective of this work is twofold: the determination of the necessary dilution for combustion stabilization, depending on the type of fuel, as well as the impact assessment on the cycle performance. In this framework, a hybrid model of the Turbec T100 mGT combustor, combining a 0D Chemical Reactor Network and 1D Laminar flame calculations, is used to first assess the flashback limits. The laminar flame speed is evaluated to predetermine the necessary minimal water dilution of the combustion air to avoid flashback for several CH4/H2 blends. Second, a thermodynamic analysis is performed to assess the impact of the flame stabilization measures on the cycle performance of the mGT using Aspen Plus. The 0D/1D simulation results show that the combustor of the Turbec T100 can operate with fuels containing up to 100% hydrogen. However, the thermodynamic analysis shows that the water dilution leads to a decreased electrical performance. Future work consists in the iterative coupling of both 0D/1D and the Aspen model to correctly predict the flashback limits, considering the altering operating conditions. To conclude, with this work, we provide a framework for future mGT operations with alternative fuels.
14
Lebedev, Yuri A. "Microwave Discharges in Liquid Hydrocarbons: Physical and Chemical Characterization." Polymers 13, no. 11 (2021): 1678. http://dx.doi.org/10.3390/polym13111678.
Full textAbstract:
Microwave discharges in dielectric liquids are a relatively new area of plasma physics and plasma application. This review cumulates results on microwave discharges in wide classes of liquid hydrocarbons (alkanes, cyclic and aromatic hydrocarbons). Methods of microwave plasma generation, composition of gas products and characteristics of solid carbonaceous products are described. Physical and chemical characteristics of discharge are analyzed on the basis of plasma diagnostics and 0D, 1D and 2D simulation.
15
Najafi, M., and Z. Benjelloun-Dabaghi. "A New Modelica Model and Scicos Simulation for 0D/1D Nonlinear Complex Systems." Oil & Gas Science and Technology - Revue de l'IFP 63, no. 6 (2008): 723–36. http://dx.doi.org/10.2516/ogst:2008042.
Full text
16
Zhang, Hao, Naoya Fujiwara, Masaharu Kobayashi, et al. "Development of patient-specific 1D-0D simulation based on MRI and SPECT data." Journal of Biorheology 32, no. 1 (2018): 2–8. http://dx.doi.org/10.17106/jbr.32.2.
Full text
17
Matsuura, Sohei, Toshio Takayama, Changyoung Yuhn, et al. "Indication of Selective Shunting During Carotid Endarterectomy: 1D–0D Hemodynamic Simulation of Cerebral Perfusion." Journal of Vascular Surgery 72, no. 1 (2020): e64. http://dx.doi.org/10.1016/j.jvs.2020.04.118.
Full text
18
Marinoni, Andrea, Matteo Tamborski, Tarcisio Cerri, et al. "0D/1D Thermo-Fluid Dynamic Modeling Tools for the Simulation of Driving Cycles and the Optimization of IC Engine Performances and Emissions." Applied Sciences 11, no. 17 (2021): 8125. http://dx.doi.org/10.3390/app11178125.
Full textAbstract:
The prediction of internal combustion engine performance and emissions in real driving conditions is getting more and more important due to the upcoming stricter regulations. This work aims at introducing and validating a new transient simulation methodology of an ICE coupled to a hybrid architecture vehicle, getting closer to real-time calculations. A one-dimensional computational fluid dynamic software has been used and suitably coupled to a vehicle dynamics model in a user function framework integrated within a Simulink® environment. A six-cylinder diesel engine has been modeled by means of the 1D tool and cylinder-out emissions have been compared to experimental data. The measurements available have been used also to calibrate the combustion model. The developed 1D engine model has been then used to perform driving cycle simulations considering the vehicle dynamics and the coupling with the energy storage unit in the hybrid mode. The map-based approach along with the vehicle simulation tool has also been used to perform the same simulation and the two results are compared to evaluate the accuracy of each approach. In this framework, to achieve the best simulation performance in terms of computational time over simulated time ratio, the 1D engine model has been used in a configuration with a very coarse mesh. Results have shown that despite the high mesh spacing used the accuracy of the wave dynamics prediction was not affected in a significant way, whereas a remarkable speed-up factor was achieved. This means that a crank angle resolution approach to the vehicle simulation is a viable and accurate strategy to predict the engine emission during any driving cycle with a computation effort compatible with the tight schedule of a design process.
19
El Khatib, N., O. Kafi, A. Sequeira, S. Simakov, Yu Vassilevski, and V. Volpert. "Mathematical modelling of atherosclerosis." Mathematical Modelling of Natural Phenomena 14, no. 6 (2019): 603. http://dx.doi.org/10.1051/mmnp/2019050.
Full textAbstract:
The review presents the state of the art in the atherosclerosis modelling. It begins with the biological introduction describing the mechanisms of chronic inflammation of artery walls characterizing the development of atherosclerosis. In particular, we present in more detail models describing this chronic inflammation as a reaction-diffusion wave with regimes of propagation depending on the level of cholesterol (LDL) and models of rolling monocytes initializing the inflammation. Further development of this disease results in the formation of atherosclerotic plaque, vessel remodelling and possible plaque rupture due its interaction with blood flow. We review plaque-flow interaction models as well as reduced models (0D and 1D) of blood flow in atherosclerotic vasculature.
20
Korte, Jana, Ehlar Sophie Klopp, and Philipp Berg. "Multi-Dimensional Modeling of Cerebral Hemodynamics: A Systematic Review." Bioengineering 11, no. 1 (2024): 72. http://dx.doi.org/10.3390/bioengineering11010072.
Full textAbstract:
The Circle of Willis (CoW) describes the arterial system in the human brain enabling the neurovascular blood supply. Neurovascular diseases like intracranial aneurysms (IAs) can occur within the CoW and carry the risk of rupture, which can lead to subarachnoid hemorrhage. The assessment of hemodynamic information in these pathologies is crucial for their understanding regarding detection, diagnosis and treatment. Multi-dimensional in silico approaches exist to evaluate these hemodynamics based on patient-specific input data. The approaches comprise low-scale (zero-dimensional, one-dimensional) and high-scale (three-dimensional) models as well as multi-scale coupled models. The input data can be derived from medical imaging, numerical models, literature-based assumptions or from measurements within healthy subjects. Thus, the most realistic description of neurovascular hemodynamics is still controversial. Within this systematic review, first, the models of the three scales (0D, 1D, 3D) and second, the multi-scale models, which are coupled versions of the three scales, were discussed. Current best practices in describing neurovascular hemodynamics most realistically and their clinical applicablility were elucidated. The performance of 3D simulation entails high computational expenses, which could be reduced by analyzing solely the region of interest in detail. Medical imaging to establish patient-specific boundary conditions is usually rare, and thus, lower dimensional models provide a realistic mimicking of the surrounding hemodynamics. Multi-scale coupling, however, is computationally expensive as well, especially when taking all dimensions into account. In conclusion, the 0D–1D–3D multi-scale approach provides the most realistic outcome; nevertheless, it is least applicable. A 1D–3D multi-scale model can be considered regarding a beneficial trade-off between realistic results and applicable performance.
21
Wang, Yan, Mingguang Yao, Xing Hua, et al. "Structural Evolution of D 5h (1)-C90 under High Pressure: A Mediate Allotrope of Nanocarbon from Zero-Dimensional Fullerene to One-Dimensional Nanotube." Chinese Physics Letters 39, no. 5 (2022): 056101. http://dx.doi.org/10.1088/0256-307x/39/5/056101.
Full textAbstract:
The hybridization of fullerene and nanotube structures in newly isolated C90 with the D 5h symmetric group (D 5h (1)-C90) provides an ideal model as a mediating allotrope of nanocarbon from zero-dimensional (0D) fullerene to one-dimensional nanotube. Raman and infrared spectroscopy combined with classical molecular dynamics simulation were used to investigate the structural evolution of D 5h (1)-C90 at ambient and high pressure up to 35.1 GPa. Interestingly, the high-pressure transformations of D 5h (1)-C90 exhibit the features of both fullerene and nanotube. At around 2.5 GPa, the D 5h (1)-C90 molecule in the crystal undergoes an orientational transition to a restricted rotation. At 6.6 GPa, the tubular hexagonal part occurs and transforms into a dumbbell-like structure at higher pressure. The material starts to amorphize above 13.9 GPa, and the transition is reversible until the pressure exceeds 25 GPa. The amorphization is probably correlated with both the intermolecular bonding and the morphology change. Our results enrich our understanding of structural changes in nanocarbon from 0D to 1D.
22
Choi, Heewon, Nam-gyu Lim, Seong Jun Lee, and Jungsoo Park. "Feasibility Study for Sustainable Use of Lithium-Ion Batteries Considering Different Positive Electrode Active Materials under Various Driving Cycles by Using Cell to Electric Vehicle (EV) Simulation." Sustainability 12, no. 22 (2020): 9764. http://dx.doi.org/10.3390/su12229764.
Full textAbstract:
Electric vehicles have been issued to achieve sustainable mobility. Main factors to sustainable electric vehicle (EV) are that lithium-ion battery (LIB) has to maintain lower cost, lighter weight, SOC (state of charge), thermal stability, and driving ranges. In this study, nickel-cobalt-manganese (NCM), lithium iron phosphate (LFP), and lithium manganese oxide (LMO), which are used as representative positive electrode materials, were applied to battery cells. Then, the battery characteristics at the system level, according to the application of different positive electrode materials, were compared and analyzed. To this end, each of the 18650 cylindrical battery cells was modeled by applying different positive electrode active materials. The battery modeling was based on a database provided by GT(Gamma Technologies)-AutoLion. To analyze the thermal stability and capacity loss according to the temperature of the battery cell by applying different C-rate discharge and temperature conditions for each positive electrode active material, an electrochemical-based zero-dimensional (0D) analysis was performed. A test was also performed to determine the model feasibility by using a MACCOR 4300 battery charger/discharger. Moreover, a lumped battery pack modeling was performed to extend the modeled battery cell to an EV battery pack. By combining the pack and one-dimensional (1D) EV models, various driving cycles were described to investigate the battery performance at the vehicle level. It was found that the 0D electrochemistry-coupled 1D vehicle model could well predict the feasible tendencies considering various positive electrode materials of the LIB battery cell.
23
Frerichs, Jelto, and Peter Eilts. "A New Combustion Model for Medium Speed Dual-Fuel Engines in the Course of 0D/1D Simulation." Methane 1, no. 3 (2022): 158–76. http://dx.doi.org/10.3390/methane1030013.
Full textAbstract:
In this paper, a predictive combustion model is developed and implemented in GT-Power. The model consists of a detailed physically/chemically based ignition delay model, including a 1D spray model. The spray model results at the start of combustion are used to initialize the combustion model. The spray zone and the homogenous natural gas/air mixture are burned with different combustion models, to account for the effect of the inhomogeneous fuel distribution. NOx-emissions are modelled using a standard Extended Zeldovich Mechanism, and for the HC-emissions, two flame quenching models are included and extended with an empirical correlation. The models are calibrated with measurement data from a single cylinder engine, except for the ignition delay model which needs no calibration. The start of combustion and the combustion parameters are predicted well for a wide range of injection timings and operation conditions. Furthermore, considering unburned fuel, the engine operation parameters BSFC and IMEP are also predicted satisfactory. Due to the detailed description of the different combustion phases, the influence of the injection timing on the NOx-emission is captured satisfactorily, with the standard NOx-model. Finally, the knock limited MFB50 is also predicted within an acceptable range.
24
ISHIGAMI, Yuta, and Marie OSHIMA. "1G24 Blood flow simulation for coupling of 3D fluid-structure interaction and 1D-0D peripheral vessel model." Proceedings of the Bioengineering Conference Annual Meeting of BED/JSME 2014.26 (2014): 225–26. http://dx.doi.org/10.1299/jsmebio.2014.26.225.
Full text
25
Irimescu, Adrian, Bianca Maria Vaglieco, Simona Silvia Merola, Vasco Zollo, and Raffaele De Marinis. "Conversion of a Small-Size Passenger Car to Hydrogen Fueling: 0D/1D Simulation of EGR and Related Flow Limitations." Applied Sciences 14, no. 2 (2024): 844. http://dx.doi.org/10.3390/app14020844.
Full textAbstract:
Hydrogen is seen as a prime choice for complete replacement of gasoline so as to achieve zero-emissions energy and mobility. Combining the use of this alternative fuel with a circular economy approach for giving new life to the existing fleet of passenger cars ensures further benefits in terms of cost competitiveness. Transforming spark ignition (SI) engines to H2 power requires relatively minor changes and limited added components. Within this framework, the conversion of a small-size passenger car to hydrogen fueling was evaluated based on 0D/1D simulation. One of the methods to improve efficiency is to apply exhaust gas recirculation (EGR), which also lowers NOx emissions. Therefore, the previous version of the quasi-dimensional model was modified to include EGR and its effects on combustion. A dedicated laminar flame speed model was implemented for the specific properties of hydrogen, and a purpose-built sub-routine was implemented to correctly model the effects of residual gas at the start of combustion. Simulations were performed in several operating points representative of urban and highway driving. One of the main conclusions was that high-pressure recirculation was severely limited by the minimum flow requirements of the compressor. Low-pressure EGR ensured wider applicability and significant improvement of efficiency, especially during partial-load operation specific to urban use. Another benefit of recirculation was that pressure rise rates were predicted to be more contained and closer to the values expected for gasoline fueling. This was possible due to the high tolerance of H2 to the presence of residual gas.
26
Montenegro, G., A. Della Torre, A. Onorati, and R. Fairbrother. "A Nonlinear Quasi-3D Approach for the Modeling of Mufflers with Perforated Elements and Sound-Absorbing Material." Advances in Acoustics and Vibration 2013 (January 14, 2013): 1–10. http://dx.doi.org/10.1155/2013/546120.
Full textAbstract:
Increasing demands on the capabilities of engine thermo-fluid dynamic simulation and the ability to accurately predict both performance and acoustics have led to the development of several approaches, ranging from fully 3D to simplified 1D models. The quasi-3D approach is proposed as a compromise between the time-demanding 3D CFD analysis and the fast 1D approach; it allows to model the acoustics of intake and exhaust system components, used in internal combustion engines, resorting to a 3D network of 0D cells. Due to its 3D nature, the model predicts high-order modes, improving the accuracy at high frequencies with respect to conventional plane-wave approaches. The conservation equations of mass and energy are solved at cell centers, whereas the momentum equation is applied to cell connections including specific source term to account for the of sound-absorbing materials and perforated elements. The quasi-3D approach has been validated by comparing the predicted transmission loss to measured data for a number of standard configurations typical of internal combustion engine exhaust systems: a reverse-flow chamber and series chambers with perforates and resistive material.
27
Choi, Seung-Mok, Kyoung-Doug Min, and Ki-Doo Kim. "Development of 0D Multizone Combustion Model and Its Coupling with 1D Cycle-Simulation Model for Medium-Sized Direct-Injection Diesel Engine." Transactions of the Korean Society of Mechanical Engineers B 34, no. 6 (2010): 615–22. http://dx.doi.org/10.3795/ksme-b.2010.34.6.615.
Full text
28
Matsuura, Sohei, Toshio Takayama, Changyoung Yuhn, et al. "Carotid Stump Pressure and Contralateral Internal Carotid Stenosis Ratio During Carotid Endarterectomies: 1D-0D Hemodynamic Simulation of Cerebral Perfusion." Annals of Vascular Diseases 14, no. 1 (2021): 39–45. http://dx.doi.org/10.3400/avd.oa.20-00166.
Full text
29
Wei, Jie, Wangzhi Zou, Zhaoyun Song, Baotong Wang, Jiaan Li, and Xinqian Zheng. "A New Integrated Model for Simulating Adaptive Cycle Engine Performance Considering Variations in Tip Clearance." Processes 11, no. 9 (2023): 2597. http://dx.doi.org/10.3390/pr11092597.
Full textAbstract:
The low-fidelity simulation method cannot meet the requirements for predicting the performance of an adaptive cycle engine (ACE), especially when considering tip clearance variations in the compression and expansion systems. The tip clearances of the components of an ACE, such as the adaptive fan and turbine, vary drastically under different operating conditions. Though the tip clearance significantly impacts the engine’s performance, including its thrust and fuel consumption, variations in tip clearance are not considered in traditional ACE simulation models. This paper developed a new integrated model for predicting ACE performance, including multi-fidelity simulation models of the components and a newly developed, simplified model for predicting tip clearance. Specifically, the integrated model consists of a zero-dimensional (0D) engine performance simulation model, a three-dimensional (3D) adaptive fan numerical simulation model, a one-dimensional (1D) low-pressure-turbine (LPT) mean line model, and a multi-dimensional (MD) tip clearance prediction model. The integrated model solved the problem of considering the impact of tip clearance on an ACE and further improved the accuracy of thrust and fuel consumption predictions. Specifically, considering variations in the tip clearances under the design conditions, the differences in the thrust and specific fuel consumption (SFC) of the ACE are 1% and 0.3%, respectively. In conclusion, the integrated model provides a useful tool for evaluating the performance of an ACE while considering tip clearance variations.
30
Irimescu, A., B. M. Vaglieco, S. S. Merola, V. Zollo, and R. De Marinis. "Conversion of a small size passenger car to hydrogen fueling: simulation of full load performance." IOP Conference Series: Materials Science and Engineering 1311, no. 1 (2024): 012004. http://dx.doi.org/10.1088/1757-899x/1311/1/012004.
Full textAbstract:
Abstract Hydrogen offers a valid choice when considering zero emissions transport. This alternative fuel is well suited for spark ignition (SI) engines and it can be implemented with relatively minor changes in terms of added components. Initial evaluations of feasibility with respect to available space for the fuel tank revealed that it is possible to convert a small size passenger car to hydrogen fueling and maintain a range comparable to the fully electric alternative. Peak power assessment showed that additional boosting was required compared to gasoline operation, close to the limit of compressor surge. As a result, the present study extended the engine speed range so as to evaluate full load performance levels that can be obtained when using hydrogen. 0D/1D simulation was applied for simulating power unit output as well as related control parameters. A dedicated laminar flame speed sub-model was implemented for including fuel chemistry effects. Predicted combustion phasing showed the required changes in ignition timing when switching fuels and revealed that the engine could be operated close to stoichiometry when using hydrogen. A reduction of torque was calculated at low engine speed, even if peak power ratings were practically the same as with gasoline fueling.
31
Zhao, Chenxi, Zhou Li, Tianjiao Fan, Chong Xiao, and Yi Xie. "Defects Engineering with Multiple Dimensions in Thermoelectric Materials." Research 2020 (May 22, 2020): 1–23. http://dx.doi.org/10.34133/2020/9652749.
Full textAbstract:
Going through decades of development, great progress in both theory and experiment has been achieved in thermoelectric materials. With the growing enhancement in thermoelectric performance, it is also companied with the complexation of defects induced in the materials. 0D point defects, 1D linear defects, 2D planar defects, and 3D bulk defects have all been induced in thermoelectric materials for the optimization of thermoelectric performance. Considering the distinct characteristics of each type of defects, in-depth understanding of their roles in the thermoelectric transport process is of vital importance. In this paper, we classify and summarize the defect-related physical effects on both band structure and transport behavior of carriers and phonons when inducing different types of defects. Recent achievements in experimental characterization and theoretical simulation of defects are also summarized for accurately determining the type of defects serving for the design of thermoelectric materials. Finally, based on the current theoretical and experimental achievements, strategies engaged with multiple dimensional defects are reviewed for thermoelectric performance optimization.
32
Zhang, Yuanpeng, Marshall McDonnell, Wei Liu, and Matthew G. Tucker. "Reverse Monte Carlo modeling for low-dimensional systems." Journal of Applied Crystallography 52, no. 5 (2019): 1035–42. http://dx.doi.org/10.1107/s160057671901080x.
Full textAbstract:
Reverse Monte Carlo (RMC) is one of the commonly used approaches for modeling total scattering data. However, to extend the capability of the RMC method for refining the structure of nanomaterials, the dimensionality and finite size need to be considered when calculating the pair distribution function (PDF). To achieve this, the simulation box must be set up to remove the periodic boundary condition in one, two or three of the dimensions. This then requires a correction to be applied for the difference in number density between the real system and the simulation box. In certain circumstances an analytical correction for the uncorrelated pairings of atoms is also applied. The validity and applicability of our methodology is demonstrated by applying the algorithms to simulate the PDF patterns of carbon systems with various dimensions, and also by using them to fit experimental data of CuO nanoparticles. This alternative approach for characterizing the local structure of nano-systems with the total scattering technique will be made available via the RMCProfile package. The theoretical formulation and detailed explanation of the analytical corrections for low-dimensional systems – 2D nanosheets, 1D nanowires and 0D nanoparticles – is also given.
33
Wurzenberger, Johann C., Roland Wanker, Ales Schuemie, Reinhard Tatschl, and Johann Krammer. "OS-D1: A Simulation Framework for 0D Engine Combustion and Pollutant Formation Combined with 1D Exhaust Gas Aftertreatment : Control of Gasoline Engine Emissions During Drive-Cycle(OS-D Advanced engine simulation (prediction of performance & emissions, transient simulation),Organized Session Papers)." Proceedings of the International symposium on diagnostics and modeling of combustion in internal combustion engines 2008.7 (2008): 105–14. http://dx.doi.org/10.1299/jmsesdm.2008.7.105.
Full text
34
Champagne, Aurélie, Samuel Dechamps, Simon M. M. Dubois, Aurélien Lherbier, Viet-Hung Nguyen, and Jean-Christophe Charlier. "Computational Atomistic Modeling in Carbon Flatland and Other 2D Nanomaterials." Applied Sciences 10, no. 5 (2020): 1724. http://dx.doi.org/10.3390/app10051724.
Full textAbstract:
As in many countries, the rise of nanosciences in Belgium has been triggered in the eighties in the one hand, by the development of scanning tunneling and atomic force microscopes offering an unprecedented possibility to visualize and manipulate the atoms, and in the other hand, by the synthesis of nano-objects in particular carbon nanostructures such as fullerene and nanotubes. Concomitantly, the increasing calculating power and the emergence of computing facilities together with the development of DFT-based ab initio softwares have brought to nanosciences field powerful simulation tools to analyse and predict properties of nano-objects. Starting with 0D and 1D nanostructures, the floor is now occupied by the 2D materials with graphene being the bow of this 2D ship. In this review article, some specific examples of 2D systems has been chosen to illustrate how not only density functional theory (DFT) but also tight-binding (TB) techniques can be daily used to investigate theoretically the electronic, phononic, magnetic, and transport properties of these atomically thin layered materials.
35
Tadros, Mina, Manuel Ventura, and C. Guedes Soares. "Optimization of the Performance of Marine Diesel Engines to Minimize the Formation of SOx Emissions." Journal of Marine Science and Application 19, no. 3 (2020): 473–84. http://dx.doi.org/10.1007/s11804-020-00156-0.
Full textAbstract:
Abstract Optimization procedures are required to minimize the amount of fuel consumption and exhaust emissions from marine engines. This study discusses the procedures to optimize the performance of any marine engine implemented in a 0D/1D numerical model in order to achieve lower values of exhaust emissions. From that point, an extension of previous simulation researches is presented to calculate the amount of SOx emissions from two marine diesel engines along their load diagrams based on the percentage of sulfur in the marine fuel used. The variations of SOx emissions are computed in g/kW·h and in parts per million (ppm) as functions of the optimized parameters: brake specific fuel consumption and the amount of air-fuel ratio respectively. Then, a surrogate model-based response surface methodology is used to generate polynomial equations to estimate the amount of SOx emissions as functions of engine speed and load. These developed non-dimensional equations can be further used directly to assess the value of SOx emissions for different percentages of sulfur of the selected or similar engines to be used in different marine applications.
36
Zhang, Hao, Naoya Fujiwara, Masaharu Kobayashi, et al. "Development of a Numerical Method for Patient-Specific Cerebral Circulation Using 1D–0D Simulation of the Entire Cardiovascular System with SPECT Data." Annals of Biomedical Engineering 44, no. 8 (2015): 2351–63. http://dx.doi.org/10.1007/s10439-015-1544-8.
Full text
37
Zhu, Yichuan, Zenon Medina-Cetina, and Alma Rosa Pineda-Contreras. "Spatio-Temporal Statistical Characterization of Boundary Kinematic Phenomena of Triaxial Sand Specimens." Materials 15, no. 6 (2022): 2189. http://dx.doi.org/10.3390/ma15062189.
Full textAbstract:
This paper follows up on a reference paper that inspired MDPI’s Topic “Stochastic Geomechanics: From Experimentation to Forward Modeling”, where global and local deformation effects on sand specimens are fully described from high resolution boundary displacement fields, and supported by its experimental database, which is open to the scientific community for further study. This paper introduces the use of spatio-temporal statistics from a subset of such an experimental database to characterize the specimens’ spatio-temporal displacement fields, populated by repeating a set of triaxial compression tests on drained, dry, vacuum-consolidated sand specimens, tested under similar experimentally controlled conditions. A three-dimensional digital image correlation (3D-DIC) technique was used to measure the specimens’ boundary displacement fields throughout the course of shearing under axial compression. Spatio-temporal first- and second-order statistics were computed for different data dimensionality conditions (0D, 0D-T, 1D-T, 3D-T) to identify and characterize the dominant failure mechanisms across different testing specimens. This allowed us to quantify localization phenomena’s spatio-temporal uncertainty. Results show that the uncertainty captured along the deformation process across different dimensionality conditions can be directly associated with different failure mechanisms, including localization patterns, such as the onset and evolution of shear, compression, and expansion bands. These spatio-temporal observations show the dependencies between locally distinctive displacement regions over a specimen’s surface, and across different times during a specimen’s shearing process. Results of this work provide boundary spatio-temporal statistics of experimental evidence in sands, which sets the basis for the development of research on the numerical simulation of sand’s constitutive behavior. Moreover, it allows to add a new understanding on the effect of uncertainty on the mechanistic interpretation of sands’ kinematic phenomena.
38
Wanker, Roland J., Johann C. Wurzenberger, and Henrik A. Schuemie. "Three-Way Catalyst Light-off During the NEDC Test Cycle: Fully Coupled 0D/1D Simulation of Gasoline Combustion, Pollutant Formation and Aftertreatment Systems." SAE International Journal of Fuels and Lubricants 1, no. 1 (2008): 1373–86. http://dx.doi.org/10.4271/2008-01-1755.
Full text
39
Jeong, Soo-Jin. "CFD Simulation of Pre-Chamber Spark-Ignition Engines—A Perspective Review." Energies 17, no. 18 (2024): 4696. http://dx.doi.org/10.3390/en17184696.
Full textAbstract:
The growing demand to reduce emissions of pollutants and CO2 from internal combustion engines has led to a critical need for the development of ultra-lean burn engines that can maintain combustion stability while mitigating the risk of knock. One of the most effective techniques is the pre-chamber spark-ignition (PCSI) system, where the primary combustion within the cylinder is initiated by high-energy reactive gas jets generated by pilot combustion in the pre-chamber. Due to the complex physical and chemical processes involved in PCSI systems, performing 3D CFD simulations is crucial for in-depth analysis and achieving optimal design parameters. Moreover, combining a detailed CFDs model with a calibrated 0D/1D model is expected to provide a wealth of new insights that are difficult to gather through experimental methods alone, making it an indispensable tool for improving the understanding and optimization of these advanced engine systems. In this context, numerous previous studies have utilized CFD models to optimize key design parameters, including the geometric configuration of the pre-chamber, and to study combustion characteristics under various operating conditions in PCSI engines. Recent studies indicate that several advanced models designed for conventional spark-ignition (SI) engines may not accurately predict performance under the demanding conditions of Turbulent Jet Ignition (TJI) systems, particularly when operating in lean mixtures and environments with strong turbulence–chemistry interactions. This review highlights the pivotal role of Computational Fluid Dynamics (CFDs) in optimizing the design of pre-chamber spark-ignition (PCSI) engines. It explores key case studies and examines both the advantages and challenges of utilizing CFDs, not only as a predictive tool but also as a critical component in the design process for improving PCSI engine performance.
40
Bianchi, Fiammetta Rita, Barbara Bosio, Arianna Baldinelli, and Linda Barelli. "Optimization of a Reference Kinetic Model for Solid Oxide Fuel Cells." Catalysts 10, no. 1 (2020): 104. http://dx.doi.org/10.3390/catal10010104.
Full textAbstract:
Solid oxide fuel cells (SOFCs) stand out among other fuel cell types because of their specific characteristics. The high operating temperature permits to reach optimal conductivity and favours kinetics without requiring noble metal catalysts. The SOFC behaviour analysis is fundamental to optimise operating conditions and to obtain the best performance. For this purpose, specific models are studied to investigate the electrochemical kinetics, which is the most critical aspect in the simulation. This is closely linked to cell materials and structure, as well as to operating conditions (feed composition and temperature above all) that influence cell polarization effects. The present work aims at evaluating these contributions by means of a semi-empirical kinetic formulation based on both theoretical and experimental approaches. A dedicated experimental campaign on an anode-supported NiYSZ/8YSZ/GDC-LSCF button cell is performed to identify experimental parameters. Each working variable is changed singularly to understand its specific effect, avoiding the overlap of multiple effects. The studied kinetics is validated using a 0D model to evaluate global cell operation, and a 1D model to estimate occurring mechanisms along anode thickness. The comparison between experimental and simulated data allows a preliminary validation of the proposed model, providing a base for subsequent more specific studies.
41
Di Lorenzo, Giuseppe, Emma Frosina, Luigi De Petrillo, et al. "Design and Development of Hybrid-Electric Propulsion Model for Aeronautics." MATEC Web of Conferences 304 (2019): 03012. http://dx.doi.org/10.1051/matecconf/201930403012.
Full textAbstract:
Nowadays, worldwide environmental issue, associated to reduction of pollutant and greenhouse emissions are gaining considerable attention. Aviation sector contribution to the whole CO2 released accounts to around 2%, but it is expected to grow in the next future due to increase of demand. Probably, combustion engine design and fuel efficiency have already reached their optimum technology level and only a breakthrough as hybrid-electric propulsion could be able to satisfy the new international more demanding requirements. However, an improvement of the technology readiness level of hybrid-electric propulsion is strongly necessary and many operational and safety challenges should be addressed. In the work here reported, a hybrid-electric model was designed and developed for general aviation aircrafts, by means of the Mathworks® Matlab – Simulink 1D/0D simulation environment. Both thermal and electric energy storage units, transmission systems and power management devices were considered and the overall performances were evaluated during cruise phase and a conventional training mission, characterized by several run(lap) “touch-and-go”. Furthermore, an innovative mathematical methodology was implemented for battery pack discharge profile interpolation. Finally, reliability and accuracy of the new proposed model were evaluated through comparison with the commercial code Simcenter AMESim® software and an average bias only equal to 5% was achieved.
42
Irimescu, Adrian, Bianca Maria Vaglieco, Simona Silvia Merola, Vasco Zollo, and Raffaele De Marinis. "Conversion of a Small-Size Passenger Car to Hydrogen Fueling: Evaluating the Risk of Backfire and the Correlation to Fuel System Requirements through 0D/1D Simulation." Energies 16, no. 10 (2023): 4201. http://dx.doi.org/10.3390/en16104201.
Full textAbstract:
Hydrogen is an effective route for achieving zero carbon dioxide emissions, with a contained cost compared to electric powertrains. When considering the conversion of spark ignition (SI) engines to H2 fueling, relatively minor changes are required in terms of added components. This study looks at the possibility of converting a small-size passenger car powered by a turbocharged SI unit. The initial evaluation of range and peak power showed that overall, the concept is feasible and directly comparable to the electric version of the vehicle in terms of powertrain performance. Injection phasing effects and cylinder imbalance were found to be potential issues. Therefore, the present work applied an 0D/1D simulation for investigating the effects of hydrogen fueling with respect to the likelihood of backfire. A range of engine speeds and load settings were scrutinized for evaluating the possibility of achieving the minimal risk of abnormal combustion due to pre-ignition. Ensuring the correct flow was predicted to be essential, especially at high loads and engine speeds. Fuel delivery phasing with respect to valve intake and closing events was also found to be a major factor that influenced not only backfire occurrence but conversion efficiency as well. Interactions with the electronic control unit were also evaluated, and additional requirements compared to standard conversion kits for LPG or CNG fueling were identified.
43
Irimescu, Adrian, Bianca Maria Vaglieco, Simona Silvia Merola, Vasco Zollo, and Raffaele De Marinis. "Conversion of a Small-Size Passenger Car to Hydrogen Fueling: Simulation of CCV and Evaluation of Cylinder Imbalance." Machines 11, no. 2 (2023): 135. http://dx.doi.org/10.3390/machines11020135.
Full textAbstract:
In the efforts to achieve zero-emission transportation, hydrogen offers a valid choice as a complete replacement of gasoline. Adapting spark ignition (SI) engines to this alternative fuel can be implemented with relatively minor changes and limited investment in added components. The conversion of a small-size passenger car to hydrogen fueling was evaluated initially from the perspective of achievable range and peak power. Overall, the concept was found to be feasible and comparable to the fully electric version of the vehicle. Cylinder imbalance was found to be one of the possible issues compared to gasoline operation. This study looks in more detail at cycle-to-cycle variability (CCV) and how this could influence vehicle dynamics as well as noise–harshness–vibration (NHV). CCV was simulated with a 0D/1D approach in vehicle-relevant engine speed–load conditions. A dedicated laminar flame speed sub-model was implemented so as to include fuel chemistry effects, while CCV was simulated by inducing perturbations in the initial combustion stages and fuel system characteristics as well as variation of air–fuel ratio throughout flame propagation. Significant improvement of stability was predicted with hydrogen, while cylinder imbalance was found to be one of the main sources of variability. Applying algorithms that compensate for the imbalance through individual injection valve regulation may not be enough to mitigate the identified issue, and more extensive changes of control strategies could be required. The start of injection settings may need to be adapted for each operating condition to maximize the effect of H2 combustion stabilization.
44
Shen, Haosheng, Fumiao Yang, Dingyu Jiang, et al. "Parametric Investigation on the Influence of Turbocharger Performance Decay on the Performance and Emission Characteristics of a Marine Large Two-Stroke Dual Fuel Engine." Journal of Marine Science and Engineering 12, no. 8 (2024): 1298. http://dx.doi.org/10.3390/jmse12081298.
Full textAbstract:
Identifying and analyzing the engine performance and emission characteristics under the condition of performance decay is of significant reference value for fault diagnosis, condition-based maintenance, and health status monitoring. However, there is a lack of relevant research on the currently popular marine large two-stroke dual fuel (DF) engines. To fill the research gap, a detailed zero-/one-dimensional (0D/1D) model of a marine two-stroke DF engine employing the low-pressure gas concept is first established in GT-Power (Version 2020) and validated by comparing the simulation and measured results. Then, three typical types of turbocharger performance decays are defined including turbine efficiency decay, turbine nozzle ring area decay, and turbocharger shaft mechanical efficiency decay. Finally, the three types of decays are introduced to the engine simulation model and parametric runs are performed in both diesel and gas modes to identify and analyze their impacts on the performance and emission characteristics of the investigated marine DF engine. The results reveal that turbocharger performance decay has a significant impact on engine performance parameters, such as brake efficiency, engine speed, boost pressure, etc., as well as CO2 and NOx emissions, and the specified limit value on certain engine operational parameters will be exceeded when turbocharger performance decays to a certain extent. The changing trend of engine performance and emission parameters as turbocharger performance deteriorates are generally consistent in both operating modes but with significant differences in the extent and magnitude, mainly due to the distinct combustion process (Diesel cycle versus Otto cycle). Furthermore, considering the relative decline in brake efficiency, engine speed drop, and relative increase in CO2 emission, the investigated engine is less sensitive to the turbocharger performance decay in gas mode. The simulation results also imply that employing a variable geometry turbine (VGT) is capable of improving the brake efficiency of the investigated marine DF engine.
45
Liu, Cong, Baiqing Li, Zhiqiang Wei, Zongwei Zhang, Zezhong Shan, and Yu Wang. "Effects of Wake Separation on Aerodynamic Interference Between Rotors in Urban Low-Altitude UAV Formation Flight." Aerospace 11, no. 11 (2024): 865. http://dx.doi.org/10.3390/aerospace11110865.
Full textAbstract:
In recent years, unmanned aerial vehicle (UAV) formation flight has become an effective strategy for urban air mobility (UAM). However, close rotor separation during formation flight leads to complex aerodynamic interference between rotors, significantly affecting UAV flight performance and operational safety. This study systematically examines the effects of axial and lateral rotor separation on the rotor’s thrust performance through wind tunnel experiments. The tests simulate horizontal, vertical, and hovering states by generating relative airflow in the wind tunnel, focusing primarily on the thrust coefficient changes of the bottom rotor at various separations. The results are compared with a single rotor operating under the same conditions without wake interference. Additionally, computational fluid dynamics (CFD) simulations using the Fluent software were conducted to investigate the effect of wake interactions by analyzing the velocity flow field between the two rotors in different separations. Both the experimental and simulation results demonstrate that rotor aerodynamic performance is notably influenced by wake interactions. Under hovering and vertical states, substantial aerodynamic interference occurs in the region directly beneath the top rotor, within 1D ≤ Z ≤ 3D. This interference gradually diminishes as the rotor separation increases. Additionally, the thrust coefficient of the bottom rotor decreases with increasing flight speed due to the wake, and at higher flight speeds, the wake tends to contract. When the lateral separation is X = 0D, the mid-sectional flow field of the two rotors exhibits symmetry; however, with lateral separation, the symmetry of the bottom rotor’s wake velocity field is disrupted. During the horizontal flight, the rotor wake tilts backward due to the relative airflow, and the extent of this influence is governed by both rotor rotational speed and flight velocity. Therefore, when UAVs operate in formation, it is crucial to account for these factors affecting aerodynamic performance, and rotor separation must be optimized to enhance flight safety and efficiency.
46
Zheng, Yunxin, Zhiping Hu, Xiang Ren, Rui Wang, Enxiang Zhang, and Zhao Long. "Effects of Partial Supporting Pile Removal from Deep Foundation Pits by Shallow Excavation Method in Loess Areas." Advances in Materials Science and Engineering 2021 (August 27, 2021): 1–13. http://dx.doi.org/10.1155/2021/9934113.
Full textAbstract:
Partial supporting piles removal from deep foundation pit may lead to large-scale foundation pit collapse, resulting in severe consequences. Various studies have investigated the underpinning technology of cutting abutment piles by combining field monitoring and numerical simulation, but there are few studies on cutting supporting piles of foundation pit by the shallow excavation method. Taking an actual deep and large foundation pit as an example, the finite element method (FEM) was adopted to study the surface settlement and the changing trend of the force and displacement of the supporting pile caused by cutting piles during the shallow excavation of double tunnels. The FEM results were verified with the field monitoring data. The simulation results show that the surface settlement around the foundation pit mainly occurs at the pile cutting stage under different excavation sequences (0D, 1D, 2D), and the main distribution area is the one-fold diameter area outside the double tunnel. After the supporting piles are partially cut, the bending moment and displacement of the lower part of the broken piles differ significantly due to different excavation sequences, but the bending moment and displacement of the upper part of the broken piles are basically similar. In the process of removing the supporting piles, the Earth pressure behind the piles is redistributed, and the load is mainly transferred to the adjacent supporting piles outside the tunnel within the radius of one time of the tunnel diameter. However, the load is not evenly transferred to the adjacent supporting piles. Some recommendations for the reinforcement scheme of the supporting structure during cutting supporting piles in deep foundation pit are also proposed. The research results can provide theoretical basis and practical guidance for the construction of similar projects in the future.
47
Moridis, George, Niwit Anantraksakul, and Thomas A. Blasingame. "The Partial Transformational Decomposition Method for a Hybrid Analytical/Numerical Solution of the 3D Gas-Flow Problem in a Hydraulically Fractured Ultralow-Permeability Reservoir." SPE Journal 26, no. 04 (2021): 2440–67. http://dx.doi.org/10.2118/199015-pa.
Full textAbstract:
Summary The analysis of gas production from fractured ultralow-permeability (ULP) reservoirs is most often accomplished using numerical simulation, which requires large 3D grids, many inputs, and typically long execution times. We propose a new hybrid analytical/numerical method that reduces the 3D equation of gas flow into either a simple ordinary-differential equation (ODE) in time or a 1D partial-differential equation (PDE) in space and time without compromising the strong nonlinearity of the gas-flow relation, thus vastly decreasing the size of the simulation problem and the execution time. We first expand the concept of pseudopressure of Al-Hussainy et al. (1966) to account for the pressure dependence of permeability and Klinkenberg effects, and we also expand the corresponding gas-flow equation to account for Langmuir sorption. In the proposed hybrid partial transformational decomposition method (TDM) (PTDM), successive finite cosine transforms (FCTs) are applied to the expanded, pseudopressure-based 3D diffusivity equation of gas flow, leading to the elimination of the corresponding physical dimensions. For production under a constant- or time-variable rate (q) regime, three levels of FCTs yield a first-order ODE in time. For production under a constant- or time-variable pressure (pwf) regime, two levels of FCTs lead to a 1D second-order PDE in space and time. The fully implicit numerical solutions for the FCT-based equations in the multitransformed spaces are inverted, providing solutions that are analytical in 2D or 3D and account for the nonlinearity of gas flow. The PTDM solution was coded in a FORTRAN95 program that used the Laplace-transform (LT) analytical solution for the q-problem and a finite-difference method for the pwf problem in their respective multitransformed spaces. Using a 3D stencil (the minimum repeatable element in the horizontal well and hydraulically fractured system), solutions over an extended production time and a substantial pressure drop were obtained for a range of isotropic and anisotropic matrix and fracture properties, constant and time-variable Q and pwf production schemes, combinations of stimulated-reservoir-volume (SRV) and non-SRV subdomains, sorbing and nonsorbing gases of different compositions and at different temperatures, Klinkenberg effects, and the dependence of matrix permeability on porosity. The limits of applicability of PTDM were also explored. The results were compared with the numerical solutions from a widely used, fully implicit 3D simulator that involved a finely discretized (high-definition) 3D domain involving 220,000 elements and show that the PTDM solutions can provide accurate results for long times for large well drawdowns even under challenging conditions. Of the two versions of PTDM, the PTD-1D was by far the better option and its solutions were shown to be in very good agreement with the full numerical solutions, while requiring a fraction of the memory and orders-of-magnitude lower execution times because these solutions require discretization of only the time domain and a single axis (instead of three). The PTD-0D method was slower than PTD-1D (but still much faster than the numerical solution), and although its solutions were accurate for t < 6 months, these solutions deteriorated beyond that point. The PTDM is an entirely new approach to the analysis of gas flow in hydraulically fractured ULP reservoirs. The PTDM solutions preserve the strong nonlinearity of the gas-flow equation and are analytical in 2D or 3D. This being a semianalytical approach, it needs very limited input data and requires computer storage and computational times that are orders-of-magnitude smaller than those in conventional (numerical) simulators because its discretization is limited to time and (possibly) a single spatial dimension.
48
Tatarchuk, Tetiana. "Studying the Defects in Spinel Compounds: Discovery, Formation Mechanisms, Classification, and Influence on Catalytic Properties." Nanomaterials 14, no. 20 (2024): 1640. http://dx.doi.org/10.3390/nano14201640.
Full textAbstract:
Spinel ferrites demonstrate extensive applications in different areas, like electrodes for electrochemical devices, gas sensors, catalysts, and magnetic adsorbents for environmentally important processes. However, defects in the real spinel structure can change the many physical and chemical properties of spinel ferrites. Although the number of defects in a crystal spinel lattice is small, their influence on the vast majority of physical properties could be really decisive. This review provides an overview of the structural characteristics of spinel compounds (e.g., CoFe2O4, NiFe2O4, ZnFe2O4, Fe3O4, γ–Fe2O3, Co3O4, Mn3O4, NiCo2O4, ZnCo2O4, Co2MnO4, etc.) and examines the influence of defects on their properties. Attention was paid to the classification (0D, 1D, 2D, and 3D defects), nomenclature, and the formation of point and surface defects in ferrites. An in-depth description of the defects responsible for the physicochemical properties and the methodologies employed for their determination are presented. DFT as the most common simulation approach is described in relation to modeling the point defects in spinel compounds. The significant influence of defect distribution on the magnetic interactions between cations, enhancing magnetic properties, is highlighted. The main defect-engineering strategies (direct synthesis and post-treatment) are described. An antistructural notation of active centers in spinel cobalt ferrite is presented. It is shown that the introduction of cations with different charges (e.g., Cu(I), Mn(II), Ce(III), or Ce(IV)) into the cobalt ferrite spinel matrix results in the formation of various point defects. The ability to predict the type of defects and their impact on material properties is the basis of defect engineering, which is currently an extremely promising direction in modern materials science.
49
Laroche, Emmanuel, David Donjat, and Philippe Reulet. "A Combined Experimental and Numerical Characterization of the Flowfield and Heat Transfer around a Multiperforated Plate with Compound Angle Injection." Energies 14, no. 3 (2021): 613. http://dx.doi.org/10.3390/en14030613.
Full textAbstract:
The aerodynamic and thermal behaviour of multiperforated zones in combustors is essential to the development of future combustion chambers. Detailed databases are therefore crucial for the validation of RANS/LES solvers, but also regarding the derivation of heat transfer correlations used in 0D/1D in-house codes developed by engine manufacturers. In the framework of FP7 EU SOPRANO Program, the test-rig used in a previous study is modified to be compatible with anisothermal conditions. The plate studied is a 12:1 model with a 90∘ compound angle injection. A heating system is used to generate a moderate temperature gradient of about 20 K between the secondary hot flow and the main cold flow. The aerodynamic field is acquired by a PIV 2D-3C (Stereo Particle Image Velocimetry) system. The surface heat transfer coefficient is derived based on surface temperature distribution acquisitions. Several heating power levels are tested, which allows evaluating the convective heat transfer coefficient and reference temperature through a linear regression. Measurements are conducted on both sides of the plate, which also gives access to those quantities on the injection/suction sides. From a numerical point of view, the configuration is studied using the unstructured ONERA in-house CEDRE solver with an advanced Reynolds Stress Model. A systematic comparison is presented between the experimental and numerical database. Due to the high blowing ratio, the film protection is low in the first rows, with a convective heat transfer coefficient enhancement around three, and freestream cold air brought close to the wall by vortices created at injection. After four rows, the film is building up, leading gradually to a better insulation of the wall. The comparison with the numerical simulation exhibits a qualitative agreement on the main flow structures. However, the mixing between the jets, the film and the freestream is underestimated by the calculation.
50
Giardiello, Giovanni, Alfredo Gimelli, Davide Riccio, and Giuseppe Zeppa. "An Automated Geometric Analysis and Characterization of an Oil-Lubricated Twin-Screw Compressor for Predictive Modeling." Journal of Physics: Conference Series 2893, no. 1 (2024): 012133. https://doi.org/10.1088/1742-6596/2893/1/012133.
Full textAbstract:
Abstract Compressor manufacturing companies are showing a growing interest in the development of validated compressor simulation models capable of predicting the behaviour of the machine if subjected to appropriate modifications. A validated predictive model of the entire compressor is useful for analysing the influence of the variation of some fundamental parameters, such as the variation of volumes or new inlet and outlet sections, on the behaviour of the machine. To create these models, geometric parameters such as the variation in volumes, the variation in inlet and outlet sections and the presence of leakage or blowhole phenomena must be provided as input. The precision of these geometric parameters is of fundamental importance for the correct operation of the model and subsequent design analyses. In this work, the authors analysed the complete geometry of an oil-lubricated twin-screw compressor. In particular, an automated calculation methodology was developed using CAD software capable of defining the characteristic curves of the volumes and areas of the compressor: starting from the geometries of the rotors and the stator case, the fluid volumes delimited at the bottom by the rotors and at the top by the case were defined through a Boolean subtraction operation. Subsequently, the volumes that complete the compression phase together were isolated and, through an automatic kinematic analysis with steps of 5° of rotation, starting from the zero reference (null volumes), the characteristic curves of the volumes and inlet and outlet areas were defined through the use of special virtual sensors. The passage sections of the leakage and blowhole leaks were defined in the same way. Particular attention was paid to the analysis of leakage and blowhole phenomena, the presence of which determines a reverse flow of part of the mass flow rate of air during the compression phase, resulting in a decrease in volumetric efficiency. Knowledge of this data is of fundamental importance for the subsequent creation of the 1D/0D model.