Academic literature on the topic 'CAD, 3D modelling, flight simulation, design'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'CAD, 3D modelling, flight simulation, design.'
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.
Journal articles on the topic "CAD, 3D modelling, flight simulation, design"
1
Karunakaran, Sreedhar. "Innovative exploration of safe in-flightcrew escape options." Aircraft Engineering and Aerospace Technology 90, no. 8 (November 5, 2018): 1221–26. http://dx.doi.org/10.1108/aeat-09-2016-0151.
Full textAbstract:
Purpose The purpose of this paper is to explore various in-flight crew escape options of a prototype transport aircraft and finalize the option offering safest crew egress for different combinations of contingencies and flight conditions. Design/methodology/approach Various egress options were explored through simulation in a computational fluid dynamics (CFD) software using aircraft 3D CAD model and scalable digital mannequins. For this, certain important contingencies which best describe the extreme aircraft behaviour were identified. Crew escape options, which have least external interference in expected egress trajectory, were selected. Several test simulations representing each feasible combination of contingency, escape option and flight condition were simulated. The option which offers safe crew escape in each test case is deemed to be the safest egress option for the test aircraft. Findings Among five options explored, crew escape through forward ventral hatch provided the safest crew escape for all test cases. The selected option was validated for robustness with additional test cases modelling different anthropometric characteristics of 5th and 50th percentile pilot populations with different postures. Originality/value In-flight validation of safe crew escape option is infeasible by actual trial. Exploration of safe crew options for required number of test cases by any analytical method or by wind tunnels tests is tedious, time consuming and extremely expensive. On the other hand, exploration of safest crew option by CFD, besides being first of its kind, provides convenient option to configure, test and validate different test cases with unmatched benefits in time, cost and simplicity.
2
Ricotta, V., R. I. Campbell, T. Ingrassia, and V. Nigrelli. "A new design approach for customised medical devices realized by additive manufacturing." International Journal on Interactive Design and Manufacturing (IJIDeM) 14, no. 4 (September 7, 2020): 1171–78. http://dx.doi.org/10.1007/s12008-020-00705-5.
Full textAbstract:
AbstractThe aim of this work is the design of a new customised elbow orthosis completely realized by Additive Manufacturing and the development of generative algorithms for parametric modelling and creation of 3D patterns to be adapted to the CAD model. This work describes a method to perfect the design of a custom elbow orthosis. A reverse engineering approach has been used to digitalize the patient’s arm and the subsequent CAD modelling of the structure of the custom elbow orthosis has been performed. In particular, two algorithms have been implemented for the creation of 3D patterns and Voronoi tessellations. Subsequently, FEM analyses have been carried out to validate the design. Finally, a prototype of the elbow orthosis with Voronoi tessellation has been realized by means of the SLS technology. The results obtained have demonstrated that the implemented algorithm solved the problems found during CAD modelling with conventional software. Furthermore, the results of FEM analyses have validated the design choices. All this allowed realizing the prototype by AM technologies without problems. Moreover, the new proposed modelling approaches allows creating, in an interactive way, patterns on complex surfaces. The results of this research activity present innovative elements of originality in the CAD modelling sector, which can contribute to solving problems related to the modelling for Additive Manufacturing. Furthermore, another innovative characteristic of the device is the use of torsion springs that simulate the action of physiotherapists during exercises for patient rehabilitation.
3
Buranský, Ivan, Martin Necpal, and Matej Bračík. "3D Model Optimization of Four-Facet Drill for 3D Drilling Simulation." Research Papers Faculty of Materials Science and Technology Slovak University of Technology 24, no. 38 (September 1, 2016): 87–93. http://dx.doi.org/10.1515/rput-2016-0043.
Full textAbstract:
Abstract The article is focused on optimization of four-facet drill for 3D drilling numerical modelling. For optimization, the process of reverse engineering by PowerShape software was used. The design of four-facet drill was created in NumrotoPlus software. The modified 3D model of the drill was used in the numerical analysis of cutting forces. Verification of the accuracy of 3D models for reverse engineering was implemented using the colour deviation maps. The CAD model was in the STEP format. For simulation software, 3D model in the STEP format is ideal. STEP is a solid model. Simulation software automatically splits the 3D model into finite elements. The STEP model was therefore more suitable than the STL model.
4
Cofaru, Nicolae Florin, Lucian Ion Roman, Valentin Oleksik, and Adrian Pascu. "Generalized Modelling of the Stabilizer Link and Static Simulation Using FEM." ACTA Universitatis Cibiniensis 68, no. 1 (December 1, 2016): 16–21. http://dx.doi.org/10.1515/aucts-2016-0004.
Full textAbstract:
Abstract This paper proposes an organological approach of one of the components of front suspension, namely anti-roll power link. There will be realized a CAD 3D modelling of this power link. 3D modelling is generalized and there were used the powers of Catia V5R20 software. Parameterized approach provides a high flexibility in the design, meaning that dimensional and shape changes of the semi-power link are very easy to perform just by changing some parameters. Several new versions are proposed for the anti-roll power link body. At the end of the work, it is made a static analysis of the semi-power link model used in the suspension of vehicles OPEL ASTRA G, ZAFIRA, MERIVA, and constructive optimization of its body.
5
Shriwise, Patrick C., John R. Tramm, Andrew Davis, and Paul K. Romano. "TOWARDS CAD-BASED GEOMETRY MODELLING WITH THE RANDOM RAY METHOD." EPJ Web of Conferences 247 (2021): 03023. http://dx.doi.org/10.1051/epjconf/202124703023.
Full textAbstract:
The Advanced Random Ray Code (ARRC) is a high performance computing application capable of high-fidelity simulations of full core nuclear reactor models. ARRC leverages a recently developed stochastic method for neutron transport, known as The Random Ray Method (TRRM), which offers a variety of computational and numerical advantages as compared to existing methods. In particular, TRRM has been shown to be capable of efficient simulation of explicit three dimensional geometry representations without assumptions about axial homogeneity. To date, ARRC has utilized Constructive Solid Geometry (CSG) combined with a nested lattice geometry which works well for typical pressurized water reactors, but is not performant for the general case featuring arbitrary geometries. To facilitate simulation of arbitrarily complex geometries in ARRC efficiently, we propose performing transport directly on Computer-Aided Design (CAD) models of the geometry. In this study, we utilize the Direct-Accelerated Geometry Monte Carlo (DAGMC) toolkit which tracks particles on tessellated CAD geometries using a bounding volume hierarchy to accelerate the process, as a replacement for ARRC’s current lattice-based accelerations. Additionally, we present a method for automatically subdividing the large CAD regions in the DAGMC model into smaller mesh cells required by random ray to achieve high accuracy. We test the new DAGMC geometry implementation in ARRC on several test problems, including a 3D pincells, 3D assemblies, and an axial section of the Advanced Test Reactor. We show that DAGMC allows for simulation of complex geometries in ARRC that would otherwise not be possible using the traditional approach while maintaining solution accuracy.
6
Millot, Grégory, Olivier Scholz, Saïd Ouhamou, Mathieu Becquet, and Sébastien Magnabal. "Development of a 3D CFD aerodynamic optimization tool and application to engine air intake design." International Journal of Numerical Methods for Heat & Fluid Flow 30, no. 9 (June 6, 2019): 4219–39. http://dx.doi.org/10.1108/hff-06-2018-0276.
Full textAbstract:
PurposeThe paper deals with research activities to develop optimization workflows implying computational fluid dynamics (CFD) modelling. The purpose of this paper is to present an industrial and fully-automated optimal design tool, able to handle objectives, constraints, multi-parameters and multi-points optimization on a given CATIA CAD. The work is realized on Rapid And CostEffective Rotorcraft compound rotorcraft in the framework of the Fast RotorCraft Innovative Aircraft Demonstrator Platform (IADP) within the Clean Sky 2 programme.Design/methodology/approachThe proposed solution relies on an automated CAD-CFD workflow called through the optimization process based on surrogate-based optimization (SBO) techniques. The SBO workflow has been specifically developed.FindingsThe methodology is validated on a simple configuration (bended pipe with two parameters). Then, the process is applied on a full compound rotorcraft to minimize the flow distortion at the engine entry. The design of the experiment and the optimization loop act on seven design parameters of the air inlet and for each individual the evaluation is performed on two operation points, namely, cruise flight and hover case. Finally, the best design is analyzed and aerodynamic performances are compared with the initial design.Originality/valueThe adding value of the developed process is to deal with geometric integration conflicts addressed through a specific CAD module and the implementation of a penalty function method to manage the unsuccessful evaluation of any individual.
7
Stanciu, Alexandru Lucian, Nicoleta Pascu, Constantin Dogariu, and Cristina Mohora. "Researches regarding scale reduced models for the optimisation of the aerodynamic coefficient." MATEC Web of Conferences 290 (2019): 04011. http://dx.doi.org/10.1051/matecconf/201929004011.
Full textAbstract:
Within the lifecycle of the product, the reduced models are very important for the experimental validation of the prototype. The modelling, simulation and optimization stage precedes the prototype realization, being part of the computer aided design (CAD), computer aided engineering (CAE). The physical model is a physical layout or test setup that reproduces, on a small scale, the features of the original system, in our case the vehicle body layout. The paper presents an automobile reduced model, with the aim to study the aerodynamic theory. The paper presents the algorithms of conceptual design of the scale reduced model, namely: 3D modelling, small scale modelling technology and geometric shape optimization solutions using different CAD-CAE programs.
8
Tu, Yan Qiong, and Guang Hua Ai. "Application of Computer Simulation to Mineral Processing of Shaking-Tables." Applied Mechanics and Materials 446-447 (November 2013): 1369–74. http://dx.doi.org/10.4028/www.scientific.net/amm.446-447.1369.
Full textAbstract:
This article tells us how to use Auto CAD and 3DS MAX to design the procedure of 3D animation and the computer simulation in the mineral-separation procedure of shaking-tables. It introduces the essential factors of all parts modelling, animation parameterssetting,simulated connection and design in the mineral-separation procedure of shaking-tables. We can realize the animation and simulation of the mineral-separation procedure of shaking-tables .And we introduce the applying foreground and significance of the computer simulation technique in the Mineral processing.
9
WILSON, DAVE. "Data exchange and software integration: Interdisciplinary design challenges." Artificial Intelligence for Engineering Design, Analysis and Manufacturing 12, no. 1 (January 1998): 73–76. http://dx.doi.org/10.1017/s0890060498121145.
Full textAbstract:
Hewlett-Packard develops and markets a family of computer-aided engineering products used by high-frequency designers to model the signal path in contemporary communications systems. As design frequencies, clock speeds and packaging densities continue to increase, more designers are finding that system and circuit simulation products need to be complemented by electromagnetic simulation software to develop models for basic circuit functionality or to characterize and compensate undesired parasitic effects. The HP High-Frequency Structure Simulator (HP HFSS) is a frequency-domain, finite element-based simulator, which enables engineers to characterize high-frequency behavior in 2D (transmission lines) and arbitrary 3D structures. Links with mechanical computer aided design (CAD) software have also become more important as the 3D structures to be analyzed by HP HFSS can involve packaging parasitics when the housing in which the electrical circuitry is enclosed becomes an influence on the signal path. Depending upon the complexity of the structure to be analyzed, HP HFSS can require hundreds of Mbytes of RAM and disk during automated adaptive solution convergence processes which determine field and circuit parameter solution results to user-specified accuracies. Although computer resource requirements will always be an important consideration for users of this type of product, another important situation to address for the future involves the exchange of data between the different simulation and modelling tools required to take design from concept through simulation to manufacture. The introduction of physical simulation tools into the traditional circuit simulation arena changes the design process flow and increases the demand for improved integration and interoperability of circuit simulators, numerical EM simulators, and mechanical CAD software. This paper provides an overview of data exchange issues in high-frequency electrical–physical–mechanical design processes.
10
Barone, S., M. Casinelli, M. Frascaria, A. Paoli, and A. V. Razionale. "Interactive design of dental implant placements through CAD-CAM technologies: from 3D imaging to additive manufacturing." International Journal on Interactive Design and Manufacturing (IJIDeM) 10, no. 2 (April 22, 2014): 105–17. http://dx.doi.org/10.1007/s12008-014-0229-0.
Full textDissertations / Theses on the topic "CAD, 3D modelling, flight simulation, design"
1
Abel, Federico. "Ricostruzione virtuale del velivolo storico Caproni Ca5." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
Find full textAbstract:
Modellazione CAD e studio preliminare delle caratteristiche di un velivolo storico, il Ca5.
L’obbiettivo di questo lavoro è analizzare in dettaglio la geometria del velivolo attraverso le fonti bibliografiche a disposizione e modellarlo poi in 3D in ambiente CAD SolidWorks. Una volta completata la fase di modellazione, è stata svolta una stima delle caratteristiche aerodinamiche ed inerziali del velivolo, ottenendo così una prima valutazione delle principali derivate aerodinamiche e dei parametri necessari a valutare le prestazioni del velivolo. Infine, utilizzando l’ambiente Aerosim, sviluppato per il modulo Simulink del software di calcolo Matlab, è stato implementato un modello dinamico del velivolo per rendere possibile la simulazione del volo. In questo modo è stato possibile cercare di comprendere quali fossero le prestazioni e le caratteristiche di stabilità e di manovrabilità del velivolo.
Sono state descritte le modalità e le fasi di lavoro attraverso cui è stato possibile studiare questo velivolo e sono state anche messe in evidenza le maggiori difficoltà affrontate, dovute largamente alla mancanza di dati precisi sul velivolo; sono anche state riportate le assunzioni poste per ottenere ugualmente dei dati per quanto possibile significativi. Sono presenti una descrizione delle fasi attraverso cui è stato modellato al CAD il velivolo Ca5 e le formule utilizzate per stimare la sua aerodinamica ed i principali dati relativi a pesi, inerzie, dimensioni.
Sono inoltre incluse alcune simulazioni del volo che dimostrano come il modello di velivolo implementato utilizzando i dati calcolati in questa tesi sia “volabile” e presenti caratteristiche di volo che lo rendono pilotabile, anche se in virtuale utilizzando un joystick al posto dei comandi di volo originali.
Conference papers on the topic "CAD, 3D modelling, flight simulation, design"
1
Milli, Andrea, and Olivier Bron. "Fully Parametric High-Fidelity CFD Model for the Design Optimisation of the Cyclic Stagger Pattern of a Set of Fan Outlet Guide Vanes." In ASME Turbo Expo 2009: Power for Land, Sea, and Air. ASMEDC, 2009. http://dx.doi.org/10.1115/gt2009-59416.
Full textAbstract:
The present paper deals with the redesign of cyclic variation of a set of fan outlet guide vanes by means of high-fidelity full-annulus CFD. The necessity for the aerodynamic redesign originated from a change to the original project requirement, when the customer requested an increase in specific thrust above the original engine specification. The main objectives of this paper are: 1) make use of 3D CFD simulations to accurately model the flow field and identify high-loss regions; 2) elaborate an effective optimisation strategy using engineering judgement in order to define realistic objectives, constraints and design variables; 3) emphasise the importance of parametric geometry modelling and meshing for automatic design optimisation of complex turbomachinery configurations; 4) illustrate that the combination of advanced optimisation algorithms and aerodynamic expertise can lead to successful optimisations of complex turbomachinery components within practical time and costs constrains. The current design optimisation exercise was carried out using an in-house set of software tools to mesh, resolve, analyse and optimise turbomachinery components by means of Reynolds-averaged Navier-Stokes simulations. The original configuration was analysed using the 3D CFD model and thereafter assessed against experimental data and flow visualisations. The main objective of this phase was to acquire a deep insight of the aerodynamics and the loss mechanisms. This was important to appropriately limit the design scope and to drive the optimisation in the desirable direction with a limited number of design variables. A mesh sensitivity study was performed in order to minimise computational costs. Partially converged CFD solutions with restart and response surface models were used to speed up the optimisation loop. Finally, the single-point optimised circumferential stagger pattern was manually adjusted to increase the robustness of the design at other flight operating conditions. Overall, the optimisation resulted in a major loss reduction and increased operating range. Most important, it provided the project with an alternative and improved design within the time schedule requested and demonstrated that CFD tools can be used effectively not only for the analysis but also to provide new design solutions as a matter of routine even for very complex geometry configurations.
2
Faath, Andreas, and Reiner Anderl. "Interdisciplinary and Consistent Use of a 3D CAD Model for CAx Education in Engineering Studies." In ASME 2016 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/imece2016-65031.
Full textAbstract:
Computer Aided Design (CAD) represents one of the key lectures in the studies of mechanical and process engineering as well as several other engineering disciplines. Furthermore Computer Aided x (CAx) systems are firmly established in the product development process. A new concept of teaching for engineering studies at the Technical University of Darmstadt (TU Darmstadt) derived by project based learning is introduced using CAx process chains i.e. the CAD-Multi Body Simulation (MBS) process chain. For the first time in engineering degree a 3D CAD model is consistently used by different process chains in multiple lectures and exercises during the whole engineering study. The early integration of this 3D CAD model in the second semester lays a foundation for its usage in further lectures, courses, projects and theses. Due to the fact, that this 3D CAD model embodies a university groups’ race car, students are able to deepen their knowledge within the university group “TU Darmstadt Racing Team e.V. (DART)”. Therefore, synergies between private and student activities are promoted, e.g. students acquire knowledge about automotive engineering. Besides the virtual implementation and validation, concepts can use the prototype for implementation and validation. The suitability of the 3D CAD model for CAD education in engineering studies especially the modelling and assembling of parts and assemblies is validated by the coached exercise of the course “Computer Aided Design”. The design education of students with mechanical engineering orientated fields of studies is held as a mandatory course in the second semester of mechanical engineering degrees at TU Darmstadt since 1995 and is solely taught with modern 3D CAD Systems. The MBS process chain is validated by several projects and theses using the McNeil Swendler Corp. (MSC) Software Automated Dynamic Analysis of Mechanical Systems (ADAMS) Car. Students run MBS by using the 3D CAD model. Besides driving maneuvers, stamp tests are simulated. In this context the entire MBS process chain is passed. The 3D CAD model serves as a basis for structures, geometry and the representation of kinematic chains, guided by the 3D CAD models geometry.
3
Kannan, Ashwin, Jonathan Thewlis, and Akin Keskin. "Novel End-End System for Combustor Design and Analysis." In ASME Turbo Expo 2021: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/gt2021-60016.
Full textAbstract:
Abstract High quality geometry creation is a key step in the design process for complex modern turbomachinery subsystems such as an annular combustor assembly. In particular, parametric generation of 3D CAD geometry is an enabler for design studies and multi-disciplinary analysis. In a traditional approach, 3D CAD models are either created in a bespoke manner with respect to the engine of interest or if a parametric approach is used, the geometry is for one particular combustor configuration, which typically leads to insufficient flexibility for topological variations. In either of these cases for every combustor design, substantial manual efforts are involved in geometry creation as well as in geometry manipulation towards creation of a truncated sector model suitable for meshing and analysis. A more flexible and fully parametric approach in highly integrated and automated design processes during all product design phases is therefore necessary. The present paper focuses on the exploitation and integration of a novel geometry modelling approach into an existing and well-established combustor design and analysis system called Prometheus in order to achieve a massive step toward a fully End-to-End (E2E) system. The new system is enabling rapid combustor design and analysis by combining feature-based geometry modelling approach that enables automatic creation of an analysis compatible combustor assembly with a geometry-centric optimization system. The automated design system can manipulate 3D geometry, to create necessary script files for meshing, simulation and post-processing for a typical CFD analysis, and execute the process to analyze different designs with respect to defined design objectives and constraints. The improved system enables engineers to assess different design concepts quickly early in the design process by providing best trade-offs between design objectives but also allows the use of detailed simulation models and boundary conditions in later more mature designs stages. The paper will discuss the robustness and flexibility of the underlying parametric CAD approach, how it augments the downstream processes, which is able to handle and translate significant topological changes throughout the E2E system. It will also clearly demonstrate the efficiency gain of the automated combustor design process, which enables design engineers to make better decision faster.
4
Tching, Loi¨c, Georges Dumont, and Je´roˆme Perret. "Haptic Assembly of CAD Models Using Virtual Constraint Guidance." In ASME 2010 World Conference on Innovative Virtual Reality. ASMEDC, 2010. http://dx.doi.org/10.1115/winvr2010-3707.
Full textAbstract:
In the context of virtual reality (VR) and of computed aided design (CAD), haptic simulations are used to perform assembly tasks between 3D objects. To help the user to perform the assembly of CAD objects, we propose a new method of interactive assembly that uses both kinematic constraints and virtual guiding fixtures. Modelling a haptic assembly task as a combination of mechanical joints, we focus on the guidance of objects and on the activation cues of kinematic constraints within physical simulation. In this article, we first outline the difficulties related to the haptic-assembly of CAD objects in VR simulation. Introducing the virtual constraint guidance (VCG), we present a new method for haptic guidance that decomposes a task in two independent steps: a guiding step which use geometries as virtual fixtures to position objects, and a functional step that use kinematic constraints to perform the assembly task while deactivating locally the collisions between objects. We finally present a complete application of our method on a insertion task and present our experimental results concerning the usability of our method.
5
Sukindar, Nor Aiman, Azib Azhari Awang Dahan, Sharifah Imihezri Syed Shaharuddin, and Nor Farah Huda Abd Halim. "Performance of Low-Cost 3D Printer in Medical Application." In ASME 2021 16th International Manufacturing Science and Engineering Conference. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/msec2021-63208.
Full textAbstract:
Abstract Fused Deposition Modelling (FDM) is an additive manufacturing (AM) process that produces a physical object directly from a CAD design using layer-by-layer deposition of the filament material that is extruded via a nozzle. In industry, FDM has become one of the most used AM processes for the production of low batch quantity and functional prototypes, due to its safety, efficiency, reliability, low cost, and ability to process manufacturing-grade engineering thermoplastic. Recently, the market is flooded with the availability of low-cost printers produced by numerous companies. This research aims to investigate the effect of different porosity levels on a scaffold structure produced using a low-cost 3D printer. Comparisons of these porous structures were made in terms of Von-Mises strain, total deformation, as well as compressive stress. Various porosity levels were created by varying printing parameters, including layer height, infill density, and shell thickness by slicing the initial solid CAD file using Repetier Host 3D printing software. Finite Element Analysis (FEA) simulation was then performed on the created scaffold structures by using Ansys Workbench 19.2. The simulation result indicates that the greater porosity level will result in higher total deformation of the structure. Meanwhile, the compression test shows that the minimum strength value obtained was favourable at 22 MPa and had exceeded that of the trabecular femur (15 MPa). However, its porosity level (maximum at 52%) was still below that of the minimum threshold of porosity level of 70 percent. However, the printing parameters currently used can be adjusted in the future. Therefore, it was deduced that the low-cost 3D printer offers promising potential to fabricate different porosity structures with multiple outcomes.
6
Le Gouez, J. M. "Numerical Simulation of Non Newtonian Hemodynamics in Compliant Vessels." In ASME 2006 Pressure Vessels and Piping/ICPVT-11 Conference. ASMEDC, 2006. http://dx.doi.org/10.1115/pvp2006-icpvt-11-93801.
Full textAbstract:
The numerical simulation of hemodynamics is increasingly recognized as a valuable analysis tool for the bioengineering laboratories who design implantable vascular grafts, and it is thought to become in a not so far future a complement to the physician’s analysis for the choice of interventional methods to restore a proper irrigation in diseased arteries [1]. The detailed numerical results obtained from 3d unsteady simulations permit to verify the hypotheses formulated by physiologists concerning the evolution of arterial disease and to quantify the risks associated to medical intervention. These objectives require an accurate representation of the major physiological parameters, much more complex than that encountered in standard CFD analysis of pipe flows, which makes the computation of blood flows in compliant vessels extremely challenging to the CFD and CSM communities. A comprehensive methodology for the adaptation of existing numerical schemes to this advanced modelling issues was conducted, for the behaviour laws of the fluid and walls on the one hand, and for the unsteady boundary conditions on the other hand. The complex nature of the mathematical model formed by the coupled fluid and structural mechanics equations, completed by highly unsteady boundary conditions, led to a choice of fully time-implicit algorithms with problem matching subiterations. These algorithms are successfully applied to different 3D, unsteady haemodynamics problems in a coronary artery. The complex, patients’ dependent geometry of a stenosed artery was reconstructed in CAD format from medical imaging. The accuracy of the numerical procedure is discussed, and this methodology can open the way for the validation of physiological criteria for the design of medical apparatus and the choice of interventional methods adapted to each individual patient’s situation.
7
Li, Yaojun, and Fujun Wang. "Computer-Aided Design and Numerical Flow Analysis of Axial-Flow Pump With Inducer." In ASME 8th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2006. http://dx.doi.org/10.1115/esda2006-95369.
Full textAbstract:
Axial-flow pump equipped with inducer are widely used in marine propulsion systems. The interaction of inducer and impeller has significant effect on the performance of pump. In this study, a special axial-flow pump is designed and analysed by CAD-CFD approaches to study the interaction of inducer and impeller. The pump includes two main elements, an inducer with 3 blades mounted on a conical hub and a 6-blade impeller. The blade angle of impeller is adjustable to generate different relative circumferential angles between the inducer blade trailing edge and the impeller blade leading edge. The 3D pump solid model is generated by taking the data file as interface between hydraulic-design and 3D modelling. A computational fluid dynamics code is used to investigate the flow characteristics and performance of the axial-flow pump. Numerical simulation is performed by adopting 3D RANS equations with RNG k-epsilon turbulence model. An unstructured grid system and the finite-volume method are used for the solution procedure of the discretized governing equations for this problem. The rotator-stator interaction is treated with a multiple reference frame (MRF) strategy. Computations are performed in different cases: 7 different relative circumferential angles (Δθ) between the inducer blade trailing edge and the impeller blade leading edge, 3 different axial gaps (G) between the inducer and the impeller. Variation of the hydraulic loss in the rotator is obtained with the change of delta theta. The numerical results show that the pressure generated is minimum in case of (G = 3%D). This indicates that the interference between inducer and impeller is strong if the axial gap is small. The pump performances are predicted and compared to the experimental measurements. The current investigation leads to a thorough enough understanding of the flow characteristics in axial-flow pumps with complex configurations. Recommendations for future modifications and improvements to the pump design are also given.
8
Walvekar, Vinayak, Chandrashekhar K. Thorbole, Prasanna Bhonge, and Hamid M. Lankarani. "Birdstrike Analysis on Leading Edge of an Aircraft Wing Using a Smooth Particle Hydrodynamics Bird Model." In ASME 2010 International Mechanical Engineering Congress and Exposition. ASMEDC, 2010. http://dx.doi.org/10.1115/imece2010-37667.
Full textAbstract:
With the increase in air travel, the recent occurrences of birdstrikes on aircraft pose a major threat to human life; hence, there is a need to develop aircraft structures with a high resistance to such occurrences. According to the Federal Aviation Regulation (FAR 25.571) on Damage-Tolerance and Fatigue Evaluation of Structure (Amdt. 25-96), an airplane must be capable of successfully completing a flight during which likely structural damage might occur as a result of impact with a four-pound (1.8 kg) bird at sea-level cruise velocity or 0.85 percent of cruise velocity at 8,000 feet (2,400 m). Since the actual physical testing of a birdstrike is expensive, time-consuming, and cumbersome, this paper presents a methodology, based on the use of analytical finite element modeling and analysis, to certify an aircraft for a birdstrike. In actual physical testing for birdstrikes the mass of the bird might not be accurate and hence for certification purpose the computational modelling technique is more accurate and standardizes the certification procedure. The modeling and simulations are carried out as follows: the bird is modeled using the smooth particle hydrodynamics (SPH) technique in the LS-Dyna nonlinear finite element code. To validate this model, birdstrikes are carried out on rigid and deformable plates. The results, including displacement, Von-Mises stresses, forces, impulse, squash time and rise time, are obtained from the simulation, and non-dimensional values are plotted and compared with results from the test data. The detailed CAD geometry of the leading edge of an aircraft is modeled in CATIA V5. Meshing, connections, and material properties are then defined in the Altair Hypermesh 9.0 program. The results obtained from the birdstrike simulations on this leading edge are compared to data from the experiments, and the process is validated. Parametric studies are carried out by designing the aircraft leading edge for different values of nose radius and by assigning appropriate thickness values for leading-edge components and impacting the SPH-modeled bird at different velocities. The methodology and results obtained from simulation can be utilized in the initial design stages as well as for “certification by analysis” of an aircraft for birdstrike requirements as per federal regulations.