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Letteratura scientifica selezionata sul tema "ZERO-DIMENSIONAL (0D)"

Autore: Grafiati

Pubblicato: 11 settembre 2023

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Articoli di riviste sul tema "ZERO-DIMENSIONAL (0D)"

Kim, Soohwan, Hyundong Yoo e Hansu Kim. "Chemically anchored two-dimensional-SiOx/zero-dimensional-MoO2 nanocomposites for high-capacity lithium storage materials". RSC Advances 10, n. 36 (2020): 21375–81. http://dx.doi.org/10.1039/d0ra02462g.

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Han, Dan, Hongliang Shi, Wenmei Ming, Chenkun Zhou, Biwu Ma, Bayrammurad Saparov, Ying-Zhong Ma, Shiyou Chen e Mao-Hua Du. "Unraveling luminescence mechanisms in zero-dimensional halide perovskites". Journal of Materials Chemistry C 6, n. 24 (2018): 6398–405. http://dx.doi.org/10.1039/c8tc01291a.

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Zero-dimensional (0D) halides perovskites, in which anionic metal-halide octahedra (MX₆)⁴⁻ are separated by organic or inorganic countercations, have recently shown promise as excellent luminescent materials.

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Wu, Jie, Shuai Zhang, Jun Yan, Bingsuo Zou e Ruosheng Zeng. "A New Zero-Dimensional (CsK2)BiCl6 Metal Halide: Boosting Emission via B-Site Mn-Doping". Crystals 12, n. 11 (21 novembre 2022): 1681. http://dx.doi.org/10.3390/cryst12111681.

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The A site of zero-dimensional (0D) metal halides A3BiCl6 can be replaced by Cs and/or K, thus, four possible 0D A3BiCl6 forms exist, such as (Cs2K)BiCl6, (CsK2)BiCl6, K3BiCl6 and Cs3BiCl6. It is well known that Cs3BiCl6 has been reported. We predict that both (Cs2K)BiCl6 and K3BiCl6 do not have enough structural and thermodynamic stability, but (CsK2)BiCl6 should be a 0D stable A3BiCl6 candidate based on density functional theory (DFT). Furthermore, 0D (CsK2)BiCl6 metal halide was experimentally prepared by the solvothermal method. Though (CsK2)BiCl6 metal halide exhibits an indirect bandgap and poor luminescence properties, the emission can be boosted by B-site Mn-doping due to the efficient energy transfer from self-trapped excitons (STE) to the d-state of Mn ions. Our results enrich the family of 0D bi-based metal halides and provide guidance for the regulation of the structural and optical properties of metal halides.

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Liu, Feng, Debayan Mondal, Kai Zhang, Ying Zhang, Keke Huang, Dayang Wang, Wensheng Yang, Priya Mahadevan e Renguo Xie. "Zero-dimensional plate-shaped copper halide crystals with green-yellow emissions". Materials Advances 2, n. 11 (2021): 3744–51. http://dx.doi.org/10.1039/d1ma00061f.

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Tian, Ye, Qilin Wei, Hui Peng, Zongmian Yu, Shangfei Yao, Bao Ke, Qiuyan Li e Bingsuo Zou. "A Zero-Dimensional Organic Lead Bromide of (TPA)2PbBr4 Single Crystal with Bright Blue Emission". Nanomaterials 12, n. 13 (28 giugno 2022): 2222. http://dx.doi.org/10.3390/nano12132222.

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Blue-luminescence materials are needed in urgency. Recently, zero-dimensional (0D) organic metal halides have attractive much attention due to unique structure and excellent optical properties. However, realizing blue emission with near-UV-visible light excitation in 0D organic metal halides is still a great challenge due to their generally large Stokes shifts. Here, we reported a new (0D) organic metal halides (TPA)2PbBr4 single crystal (TPA+ = tetrapropylammonium cation), in which the isolated [PbBr4]2− tetrahedral clusters are surrounded by organic ligand of TPA+, forming a 0D framework. Upon photoexcitation, (TPA)2PbBr4 exhibits a blue emission peaking at 437 nm with a full width at half-maximum (FWHM) of 50 nm and a relatively small Stokes shift of 53 nm. Combined with density functional theory (DFT) calculations and spectral analysis, it is found that the observed blue emission in (TPA)2PbBr4 comes from the combination of free excitons (FEs) and self-trapped exciton (STE), and a small Stokes shift of this compound are caused by the small structure distortion of [PbBr4]2− cluster in the excited state confined by TPA molecules, in which the multi-phonon effect take action. Our results not only clarify the important role of excited state structure distortion in regulating the STEs formation and emission, but also focus on 0D metal halides with bright blue emission under the near-UV-visible light excitation.

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Zhu, Xingwang, Jinyuan Liu, Zhenzhen Zhao, Jia Yan, Yuanguo Xu, Yanhua Song, Haiyan Ji, Hui Xu e Huaming Li. "Hydrothermal synthesis of mpg-C3N4 and Bi2WO6 nest-like structure nanohybrids with enhanced visible light photocatalytic activities". RSC Advances 7, n. 61 (2017): 38682–90. http://dx.doi.org/10.1039/c7ra06681c.

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Due to the anisotropic growth of Bi₂WO₆, the zero-dimensional (0D) nanoparticles can be transformed into two-dimensional (2D) nanosheets, and finally self-assembled into three-dimensional (3D) nest-like structures.

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Santhoshkumar, P., K. Prasanna, Yong Nam Jo, I. Nirmal Sivagami, Suk Hyun Kang e Chang Woo Lee. "A facile and highly efficient short-time homogenization hydrothermal approach for the smart production of high-quality α-Fe2O3 for rechargeable lithium batteries". Journal of Materials Chemistry A 5, n. 32 (2017): 16712–21. http://dx.doi.org/10.1039/c7ta04797e.

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Wu, Haixia, Zhenxu Lin, Jie Song, Yi Zhang, Yanqing Guo, Wenxing Zhang e Rui Huang. "Boosting the Self-Trapped Exciton Emission in Cs4SnBr6 Zero-Dimensional Perovskite via Rapid Heat Treatment". Nanomaterials 13, n. 15 (6 agosto 2023): 2259. http://dx.doi.org/10.3390/nano13152259.

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Zero-dimensional (0D) tin halide perovskites feature extraordinary properties, such as broadband emission, high photoluminescence quantum yield, and self-absorption-free characteristics. The innovation of synthesis approaches for high-quality 0D tin halide perovskites has facilitated the flourishing development of perovskite-based optoelectronic devices in recent years. However, discovering an effective strategy to further enhance their emission efficiency remains a considerable challenge. Herein, we report a unique strategy employing rapid heat treatment to attain efficient self-trapped exciton (STE) emission in Cs4SnBr6 zero-dimensional perovskite. Compared to the pristine Cs4SnBr6, rapid thermal treatment (RTT) at 200 °C for a duration of 120 s results in an augmented STE emission with the photoluminescence (PL) quantum yield rising from an initial 50.1% to a substantial 64.7%. Temperature-dependent PL spectra analysis, Raman spectra, and PL decay traces reveal that the PL improvement is attributed to the appropriate electron–phonon coupling as well as the increased binding energies of STEs induced by the RTT. Our findings open up a new avenue for efficient luminescent 0D tin-halide perovskites toward the development of efficient optoelectronic devices based on 0D perovskites.

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Miao, Yuhang, Xiaojing Wang, Jie Sun e Zhong Yan. "Recent advances in the biomedical applications of black phosphorus quantum dots". Nanoscale Advances 3, n. 6 (2021): 1532–50. http://dx.doi.org/10.1039/d0na01003k.

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Zhang, Haihua, Qing Liao, Yishi Wu, Jianwei Chen, Qinggang Gao e Hongbing Fu. "Pure zero-dimensional Cs4PbBr6 single crystal rhombohedral microdisks with high luminescence and stability". Physical Chemistry Chemical Physics 19, n. 43 (2017): 29092–98. http://dx.doi.org/10.1039/c7cp06097a.

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Più fonti

Tesi sul tema "ZERO-DIMENSIONAL (0D)"

Wolcott, Abraham. "Zero-dimensional (0D), one-dimensional (1D) and two-dimensional (2D) nanostructures for sustainable energy production and biolabeling applications /". Diss., Digital Dissertations Database. Restricted to UC campuses, 2009. http://uclibs.org/PID/11984.

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SHARMA, PRATEEK. "GROWTH OF MOLYBDENUM DISULFIDE (MoS2) NANOSTRUCTURES AND THEIR APPLICATIONS". Thesis, DELHI TECHNOLOGICAL UNIVERSITY, 2021. http://dspace.dtu.ac.in:8080/jspui/handle/repository/18624.

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7.1. Summary The objectives of the current thesis entitled “Growth of molybdenum disulfide (MoS2) nanostructures and their applications” disclosed the structural, morphological, electrical, compositional and optical properties of MoS2 nanostructures and discussed their utility for sensing and photocatalytic applications. The MoS2 has gained a great attention because of its structural similarity with graphene [1]. The layers tuned bandgap of MoS2 possesses magnificent optical and electronic properties which exhibit a wide range of applications, i.e., catalysis, transistors, batteries, photodetectors, gas sensing, and as well as optoelectronic devices [2-16]. When the layered MoS2 nanosheets are reduced to the zero-dimensional (0D) quantum dots (QDs) then the entirely different photo-physical properties of MoS2 arises because of its quantum confinement and edge effects [17–19]. MoS2 QDs have been extensively studied due to its low toxicity, high stability, abundance availability and excellent optical properties. The production of novel and advance MoS2 nanostructures, is the fundamental step towards their implications to the numerous applications in various divisions. This thesis holds synthesis of different MoS2 nanostructures by adopting the facile hydrothermal route. The hydrothermal/solvothermal method to synthesize MoS2 was opted, due to its ability to form nanostructures at high pressure and temperatures, ease in handling, uniform production of nanomaterials and high yield [20–22]. The MoS2 nanosheets and their quantum dots were prepared by altering the size of the particles and confining them in one or all axis to explore their properties comprehensively. The optical properties of MoS2 146 nanostructures (like absorption, photoluminescence and time-resolved photoluminescence) along with the different sensing and photocatalytic applications have also been discussed in detail. 7.2. Important findings of the research work The MoS2 nanostructures were hydrothermally synthesized and their constituent phase, phase purity and the crystallite size were analysed from the XRD and compared with the respective JCPDS files. The results were then confirmed by analysing HR-TEM images, for particle size and structure. The orderly patterned fringes confirmed the formation of crystalline structure of MoS2. The optical investigations through UV-visible absorption spectroscopy, PL spectroscopy and FTIR spectroscopy had been carried out for the prepared nanostructures to recorded their optical performances. The synthesized MoS2 QDs were then employed to detect the very explosive compound, 2,4,6-trinitrophenol (TNP), which has greater explosive strength than the very well-known explosive, trinitrotoluene (TNT). The TNP or picric acid is very acidic in nature and has been used in various industries, whose waste can cause severe health-related issues and destroy the soil and water resources. The primary detection of TNP of concentration as low as 5 μM, could be recorded through this sensing probe. The highest quantum yield (QY) of the prepared quantum dots i.e., 17% had been achieved among previously reported QDs through the same hydrothermal route. Then, the absorption and PL spectra were recorded of the MoS2 QDs and used to detect the lead metal ions (Pb2+) in water bodies. The Pb2+ ions can cause severe damage to the human brain and could be a preliminary cause of cancer. The detection of Pb2+ ions in water holds great significance for the sustainability of humanity. The detection of the Pb2+ ions was pursued the 147 greater sensitivity and larger selectivity among other metal ions in water. Therefore, certain experiments were carried out and the data has been represented wisely to demonstrate the MoS2 QDs as an efficient Pb2+ ion sensor. The detection of Pb2+ of concentration as low as 50 μM is possible through this probe. The synthesized nanosheets were then employed for the photodegradation of the organic pollutant, i.e., crystal violet (CV) dye in water. The photodegradation of CV dye was performed because of the bandgap of the nanosheets, which lies in the visible region and supports the environment by using the abundant solar energy for the decomposition of an organic pollutant. The presence of the CV dye in water is a severe threat to the environment and aquatic life. Therefore, its degradation holds great significance for the upliftment of a sustainable environment. The other transition metal dichalcogenides were also synthesized. The synthesis and characterization of tungsten disulfide (WS2) QDs were carried out. The bright blue fluorescence was observed when exposed to ultraviolet light (365 nm). The prepared QDs were then employed to detect the TNP compound in water. The sensitivity and selectivity of the WS2 QDs based sensor were calculated. The primary detection of TNP of concentration as low as 0.2 μM, could be recorded through this sensing probe.

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Kaprielian, Leslie. "Modélisation 0D pour la combustion dans les moteurs à allumage commandé : développements en proche paroi et dans le front de flamme". Thesis, Paris, ENSAM, 2015. http://www.theses.fr/2015ENAM0012/document.

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Depuis quelques années, les modèles 0D trouvent un regain d'intérêt auprès des motoristes. En effet, ces modèles, fournissant aisément un comportement thermodynamique du moteur, peuvent être couplés avec des outils de contrôle moteur. Néanmoins, leur précision doit être augmentée, pour répondre aux enjeux technologiques actuels. Dans les moteurs à allumage commandé, la flamme turbulente prémélangée est modélisée comme un ensemble de flammelettes cohérentes entre elles. Cette approche généraliste nécessite un traitement particulier en proche paroi, motivé par une modification de la structure de flamme due aux couches limites thermique et cinématique. Ce présent travail propose des approches de modélisations 0D de la combustion, en proche paroi et dans la zone réactionnelle de la flamme. Pour modéliser la combustion en proche paroi, la flamme est scindée en une contribution en propagation libre, et une contribution en interaction avec les parois. Chaque contribution est divisée en une zone de transport, dans laquelle l'entraînement des gaz frais est décrit, et une zone de réaction, dans laquelle la réaction de combustion est modélisée. L'ajout d'une zone de réaction en interaction avec les parois permet de modéliser un gradient de température et une réaction de combustion ralentie en proche paroi. Pour modéliser la zone réactionnelle, une discrétisation de la flamme en N zones de réaction indépendantes est proposée. Une plage de fonctionnement moteur a été simulée avec nos approches de modélisation, afin de quantifier la variabilité des paramètres de calibration. Pour ce faire, les modèles sont calibrés sur chaque point de fonctionnement, par une méthode de minimisation de l'erreur quadratique moyenne sur la loi de dégagement d'énergie. Des corrélations aisées de paramètres de calibration peuvent être établies, en fonction de paramètres moteurs. Les résultats de simulations, obtenus à partir de ces corrélations, sont satisfaisants
Recently, the interest for zero-dimensional models has increased. Indeed, these models provide easily the engines thermodynamic behavior and can be coupled with control tools. However, their accuracy must be improved to meet the current technological challenges. In the spark ignition engines, the premixed turbulent flame is modeled as a set of coherent flamelets. This approach requires special treatment near the walls, motivated by the modifications of the flame structure due to boundary layers. The present work proposes 0D modeling of combustion near the walls and in the reaction zone of the flame. To combustion model near the walls, the flame is divided into a free propagation contribution, and an interacting contribution with the walls. Each contribution is divided into a convective zone, wherein the entrainment of fresh gas is described, and a reaction zone, wherein the combustion reaction is modeled. Adding a reaction zone near the walls allows modeling a thermal gradient and a slower combustion reaction near the walls. To model the reaction zone, a flame discretization is made into several reaction zones. An engine operating range is simulated with our models, for quantifying the calibration parameters variability. To do this, models are calibrated on each operating point, by a method of minimization of the quadratic error on the heat released rate. Linear correlations can be found, depending on engines parameters. A good agreement between experimental data and simulation results is obtained with these parameters correlations

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Capitoli di libri sul tema "ZERO-DIMENSIONAL (0D)"

Launois, H., D. Mailly, Y. Jin, F. Pardo, A. Izrael, J. Y. Marzin e B. Sermage. "Fabrication and Quantum Properties of 1D and 0D Nanostructures in III-V Semiconductors". In Science and Engineering of One- and Zero-Dimensional Semiconductors, 17–24. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4684-5733-9_3.

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"Synthesis, Characterization, and Applications of Zero-Dimensional (0D) Nanostructures". In Synthesis and Applications of Inorganic Nanostructures, 21–146. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2017. http://dx.doi.org/10.1002/9783527698158.ch2.

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"Applications of Quantum Dots in Supercapacitors". In Materials Research Foundations, 169–90. Materials Research Forum LLC, 2021. http://dx.doi.org/10.21741/9781644901250-7.

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Quantum dots (QDs) are a new class of zero-dimensional (0D) nanomaterials having unique electronic and optical properties along with biocompatibility, chemical inertness, dispersibility in water, and high specific surface area that gives them potential for biological, optoelectronic and energy related applications. Among them, charge storage supercapacitor (SC) devices have been intensively studied as the nano-sized QDs act as an excellent interface to stimulate an enhanced interaction between electrode and electrolyte resulting in superior charge storage properties of the SC. In this chapter, the latest research progress on the five representative types of QDs namely carbon nanodots (CNDs), graphene QDs (GQDs), polymer QDs (PQDs), transition metal oxide (TMO) and dichalcogenide (TMD) QDs are comprehensively introduced and their influence on the final charge storage properties of supercapacitor devices is emphatically discussed in detail. Finally, a brief outlook is given, pointing out the challenges which remain to be settled before adoption of QDs can be of widespread utility for near future energy-functional devices.

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Atti di convegni sul tema "ZERO-DIMENSIONAL (0D)"

Sundström, Elias, Bertrand Kerres e Mihai Mihăescu. "Evaluation of Centrifugal Compressor Performance Models Using Large Eddy Simulation Data". In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-57169.

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Zero-dimensional (0D) compressor performance models, which consist of several sub-models for different loss terms, are useful tools in early design stages. In this paper, one typical model for centrifugal compressors is evaluated by comparing the loss-terms predicted by the model to data extracted from experimentally validated Large-Eddy-Simulation. The simulations were run on a truck-sized turbocharger compressor with a ported shroud and a vaneless diffuser. Four operating points are considered: One mass flow at design conditions and one mass flow close to surge, on two speedlines. The performance prediction models evaluated are impeller incidence loss, impeller skin friction loss, diffuser skin friction loss, and the tip clearance loss. Results show that the total losses are well-predicted by the model at design conditions. Friction losses are approximately independent of mass flow in the LES data, while the 0D model assumes a quadratic increase. The assumption of constant tip clearance loss is validated by the LES data, and the impeller incidence loss model also fits the data well. Due to the ported shroud, most of the losses as calculated by entropy increase occur through isobaric mixing at the impeller inlet.

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Liang, Feng, Quanyong Xu, Xudong Lan e Ming Zhou. "The Comparison of Four Pressure-Thermal Models of Oil Film Bearing With the Non-Newtonian and Temperature-Viscosity Effects". In ASME 2016 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/detc2016-59127.

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The thermohydrodynamic analysis of oil film bearing is essential for high speed oil film bearing. The temperature field is coupled with the pressure field. The numerical model can be built or chosen according to the complexity of the objects and requirement of the accuracy. In this paper, four pressure-thermal (P-T) models are proposed, which are zero-dimensional temperature field coupled with Reynolds equation (0D P-T model), two-dimensional temperature field coupled with Reynolds equation (2D P-T model), two-dimensional temperature with third dimensional correction coupled with Dawson equation (2sD P-T model), three-dimensional temperature field coupled with Dawson equation (3D P-T model). The non-Newtonian and temperature-viscosity effects of the lubrication oil are considered in all the four models. Two types of cylindrical journal bearing, the bearing with/without axial grooves, are applied for the simulation. All the simulated cases are compared with the solutions of the CFX. The results show that the 0D P-T model fails to predict the behavior of high speed bearing; The 2D and 2sD P-T model have an acceptable accuracy to predict the performance of the bearing without grooves, but are not able to simulate the P-T field of the bearing with grooves because of the under-developed thermal boundary layer; The 2sD P-T model shows a great improvement when calculating the pressure field compared with the 2D P-T model; the 3D P-T model coincides well with the CFX at any condition. The comparison of these four models provides a reference to help designer choose a proper numerical model for a certain project.

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Liu, Jinlong, Christopher Ulishney e Cosmin E. Dumitrescu. "Application of Random Forest Machine Learning Models to Forecast Combustion Profile Parameters of a Natural Gas Spark Ignition Engine". In ASME 2020 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/imece2020-23973.

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Abstract Predicting internal combustion (IC) engine variables such as the combustion phasing and duration are essential to zero-dimensional (0D) single-zone engine simulations (e.g., for the Wiebe function combustion model). This paper investigated the use of random forest machine learning models to predict these engine combustion parameters as a modality to reduce expensive engine dynamometer tests. A single-cylinder four-stroke heavy-duty spark-ignition engine fueled with methane was operated at different engine speeds and loads to provide the data for training, validation, and testing the proposed correlated model. Key engine operating variables such as spark timing, mixture equivalence ratio, and engine speed were the model inputs. The performance of the models was validated by comparing the prediction dataset with the experimentally measured results. Results showed that the prediction error of the random forest machine learning algorithm was acceptable, suggesting that it can be used to predict the combustion parameters of interest with acceptable accuracy.

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Kim, Yirop, Myoungsoo Kim e Han Ho Song. "Analyzing the Effect of Engine Design Modification on the Spark-Ignition Engine Performance via Simplified Quasi-Dimensional Modeling". In ASME 2017 Internal Combustion Engine Division Fall Technical Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/icef2017-3519.

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For past decades, substantial developments have been accomplished in internal combustion (IC) engine technology, but there still remain some possible improvements. The combustion in an IC engine is a highly intricate phenomenon, thus, numerous factors correlated with different forms of loss decides the efficiency of an engine. In spark-ignition (SI) engines, the combustion duration is considered important because it plays a key role in determining the combustion phasing for best possible energy conversion. The geometry of engine components may directly change the burning rate of air-fuel mixture, therefore, it should also be considered as significant as other aspects like exhaust gas recirculation (EGR) rate or boosting in investigation of the engine performance. This is the reason the development engineers are putting their effort to design an engine with optimized flow motion. Tweaking the flow dynamics via design modification or use of auxiliary device influences the turbulence level inside the combustion chamber, thus, the burning rate as well. Intake port orientation, masking, and piston shape are one of the typical design parameters manipulated for such purpose, and profound understanding on the effect of these design parameters on burning rate is encouraged in order to assist the optimization process. The design optimization process should be based on a fundamental understanding of how the design parameters affect the flow motion and combustion characteristics. This study aims for a simpler and faster method to investigate the consequences of design modifications. As a base model, a physics-based quasi-dimensional (QD) engine model is developed for simulation of SI combustion phenomenon. It is modeled to consider the change in flow motion and turbulence properties via simplified modeling. The advantages of such QD model is that it requires much less computational resource compared to 3D CFD model, and allows a greater degree of freedom within the simulation process which facilitates parametric studies. A zero-dimensional (0D) turbulence submodel is used to describe energy cascade mechanism, and turbulence intensity is calculated reflecting the effect cause by design modification. According to the sensitivities drawn from parametric study, the results of each effect on burning rate and other engine performance properties are compared individually and collectively. A qualitative analysis suggests how sensitive each effect are at given operating conditions. The result infers that the flow concentration by port design modification boosts the burning rate, but it is advantageous in terms of fuel economy to enhance the breathing ability by valve masking. The product of this comparative study assists an intuitive understanding on how the design modification would affect the engine operations, and it is encouraged to develop the model further via validation with experiment data to provide more reliable output. It is believed that it can be utilized as a good reference in engine design process.

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