NAFEMS International Journal of CFD Case Studies最新文献_第2页

Digital Prototyping Methodology for Cyclonic Multiphase Flow Separation 旋涡多相流分离的数字样机方法

NAFEMS International Journal of CFD Case Studies Pub Date : 2016-04-01 DOI: 10.59972/zbwl6jwx

A. Kulkarni, M. Kulkarni, P. More, S. Showalter

{"title":"Digital Prototyping Methodology for Cyclonic Multiphase Flow Separation","authors":"A. Kulkarni, M. Kulkarni, P. More, S. Showalter","doi":"10.59972/zbwl6jwx","DOIUrl":"https://doi.org/10.59972/zbwl6jwx","url":null,"abstract":"Safety and reliability are fundamental requirements for gas turbine engines. Continuous health monitoring and diagnostics devices are prime enablers for the same, and gaining a lot of attention for advancements. Oil debris monitoring is one of the important elements of an engine condition monitoring system. The cyclone separator is the key component of the debris monitoring system which separates air, oil and solid particles. The separation efficiency of various phases determines the cyclone performance and is governed by highly turbulent swirling flow field. Further, the particle capture efficiency depends on successful capturing of the flow field. Cyclone performance enhancement requires a detailed understanding of turbulent swirling multiphase flow field with free and forced vortex interactions. This poses a significant challenge for physical prototyping and demands detailed computational models to resolve the anisotropic structure of a turbulent flow field with multiphase interaction. Detailed investigation of various computational models such as turbulence models, multiphase models, and drag models has been carried out to capture the complex flow physics. A structured computational approach helped to establish a CFD methodology having a close match with experimental findings for all the performance parameters of three phase separation. The methodology is validated with the experimental results with the variation between CFD and experiments observed to be less than 10% for all four performance parameters namely pressure drop, air separation efficiency, oil separation efficiency and particle capture efficiency.","PeriodicalId":183819,"journal":{"name":"NAFEMS International Journal of CFD Case Studies","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134201139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Water in Fuel Sloshing for Aircraft Fuel Tanks 飞机燃料箱中的水晃动

NAFEMS International Journal of CFD Case Studies Pub Date : 2013-03-01 DOI: 10.59972/4tp574tw

G. Hylands, C. Toomer, J. Lam

引用次数: 0

Computational Fluid Dynamics Simulations of the Complex Geometry of a Technical Textile 工业纺织品复杂几何结构的计算流体动力学模拟

NAFEMS International Journal of CFD Case Studies Pub Date : 2013-03-01 DOI: 10.59972/1jryslvs

K. Farber, J. Jasper, M. Märtin, Martin Schmitt, S. Krick, P. Farber, J. Leisen, H. Beckham

{"title":"Computational Fluid Dynamics Simulations of the Complex Geometry of a Technical Textile","authors":"K. Farber, J. Jasper, M. Märtin, Martin Schmitt, S. Krick, P. Farber, J. Leisen, H. Beckham","doi":"10.59972/1jryslvs","DOIUrl":"https://doi.org/10.59972/1jryslvs","url":null,"abstract":"The use of virtual prototypes for the prediction of relevant flow related parameters is well established in many industries such as the automotive industry. For the development of technical textiles an analogous approach is anticipated as being beneficial. However, so far the complex geometry of textiles consisting of a very large number of filaments has impeded this approach. We utilize this approach for the first time investigating a fabric, which is used during the paper forming process. The most challenging aspect for the simulation is the the process of geometry creation by use of single filaments together with the indispensable simplifications for a currently marketed fabric. Meshes of different sizes up 20 million cells have been generated and results from CFD calculations will be displayed together with an analysis of the numerical accuracy. The individual relevance of the simulation experiments will be discussed. Physical experiments at ambient temperature of laminar water flow through the same fabric under comparable conditions with a Reynolds Number of 15 based on pipe diameter of 9.0 mm and pipe volume flow rate averaged velocity magnitude of 0.00172 m/s were performed. The Reynolds Number based on the diameter of the different filaments of 0.2 mm up to 0.45 mm is approx. between 0.34 and 0.77. The experimental set up using Magnetic Resonance Imaging (MRI) will be explained. The use of this experimental approach as a means to validate the results of the simulation will be critically evaluated.","PeriodicalId":183819,"journal":{"name":"NAFEMS International Journal of CFD Case Studies","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129585386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

CFD-Supported Design of Lifeboats cfd支持的救生艇设计

NAFEMS International Journal of CFD Case Studies Pub Date : 2013-03-01 DOI: 10.59972/ffm3fczg

Hans Jo̸rgen Mo̸rch, M. Peric, Jasmin Röper, E. Schreck

{"title":"CFD-Supported Design of Lifeboats","authors":"Hans Jo̸rgen Mo̸rch, M. Peric, Jasmin Röper, E. Schreck","doi":"10.59972/ffm3fczg","DOIUrl":"https://doi.org/10.59972/ffm3fczg","url":null,"abstract":"Lifeboats are important for the safety of crew on oil platforms and marine vessels. Their design has so far been mostly based on experimental studies. However, the large number of factors which influence the loads on the lifeboat structure and its occupants makes optimization studies by experimental means both time-consuming and expensive. Besides, many effects cannot be studied at laboratory scale due to the inability to match all similarity parameters, and certain conditions cannot be realized in a laboratory. Numerical simulations based on modern computational fluid dynamics (CFD) methods could complement experimental studies if proven to be sufficiently accurate and efficient. The aim of this study is to demonstrate that this indeed is the case: comparisons between experimental data and simulation results performed by the authors so far indicate that the achieved accuracy in numerical simulations is comparable to the accuracy of experiments. It is also shown that a simulation of one drop test can be performed with sufficient accuracy in one day on a single core of a personal computer. Together with a computational method which uses overlapping grids to simplify the handling of lifeboat motion and specification of initial and boundary conditions, parametric studies of lifeboat water entry have thus become practicable.","PeriodicalId":183819,"journal":{"name":"NAFEMS International Journal of CFD Case Studies","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123796364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multi-physics Models for Friction Stir Welding Simulation 搅拌摩擦焊接仿真的多物理场模型

NAFEMS International Journal of CFD Case Studies Pub Date : 2013-03-01 DOI: 10.59972/fkwes73g

D. Mackenzie, Hongjun Li, R. Hamilton

{"title":"Multi-physics Models for Friction Stir Welding Simulation","authors":"D. Mackenzie, Hongjun Li, R. Hamilton","doi":"10.59972/fkwes73g","DOIUrl":"https://doi.org/10.59972/fkwes73g","url":null,"abstract":"Friction stir welding (FSW) is a solid-state welding technology for joining a range of metals and alloys. The FSW joining process involves several coupled non-linear phenomena including; frictional heating, large plastic deformation, material transportation and dissipative heating. Numerical simulation of the process may include some or all of these physical processes, depending on the objective of the analysis. This paper gives an overview of two continuum solid mechanics FSW simulation models of differing complexity. The first model is a simplified ANSYS thermo-mechanical finite element model with an externally applied heat source simulating frictional and dissipative heating. The model can be used to quickly evaluate temperature, stress and deformation of the welded plate for a specified heat input. The second model is an ABAQUS/EXPLICIT Arbitrary Lagrangian-Eulerian (ALE) model of the complete FSW process: plunge, dwell, travel and withdraw. The model simulates coupled frictional heating, plastic dissipation, transient heat transfer and solid-state material flow. The results obtained for transient temperature distribution, material flow, residual stress and strain, etc. are found to be consistent with experimental observations.","PeriodicalId":183819,"journal":{"name":"NAFEMS International Journal of CFD Case Studies","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121300315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimization of a Sanding System for a Tramway Car by Numerical Simulation of the Sand-Air Two-Phase Flow 基于砂气两相流数值模拟的有轨电车车厢磨砂系统优化

NAFEMS International Journal of CFD Case Studies Pub Date : 2011-04-04 DOI: 10.59972/x9am4m4u

Sebastian Möller, D. Langmayr, G. Brenn, P. Krieg

{"title":"Optimization of a Sanding System for a Tramway Car by Numerical Simulation of the Sand-Air Two-Phase Flow","authors":"Sebastian Möller, D. Langmayr, G. Brenn, P. Krieg","doi":"10.59972/x9am4m4u","DOIUrl":"https://doi.org/10.59972/x9am4m4u","url":null,"abstract":"In tramways, sanding systems are used to avoid gliding while accelerating or slowing down the vehicle under bad rail conditions. The total amount of sand required should be a minimum to reduce costs and unnecessary formation of particulate matter in road traffic. The main aim of the present paper is to minimize this total amount of sand by means of modern computational methods. For this purpose, the software ANSYS FLUENT is used to develop a numerical simulation model, which allows the flow of a sand-air mixture to be simulated under the conditions of a sanding system. Of particular importance in the approximation to reality is the correct modelling of the rebound behavior of the sand particles on the surface of the rails. For an accurate prediction of the related physics, a stochastic sub-model was implemented whose parameters were tuned using results from in-house experiments carried out for this purpose. A series of simulation computations led to suggestions of improved design variants of the end piece at the exit of the sanding device and a better focused sand jet. Finally, the improved end pieces were tested in simulations with approximated realistic geometry and boundary conditions.","PeriodicalId":183819,"journal":{"name":"NAFEMS International Journal of CFD Case Studies","volume":"38 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129429077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Towards Virtual Testing of Compression Systems in Gas Turbine Engines 燃气轮机压缩系统的虚拟测试研究

NAFEMS International Journal of CFD Case Studies Pub Date : 2011-03-01 DOI: 10.59972/gxbuf1zn

N. Sayma

{"title":"Towards Virtual Testing of Compression Systems in Gas Turbine Engines","authors":"N. Sayma","doi":"10.59972/gxbuf1zn","DOIUrl":"https://doi.org/10.59972/gxbuf1zn","url":null,"abstract":"Current trends in the computational fluid dynamics (CFD) analysis of gas turbine engines are in the direction of the so called “virtual testing”. Although this term is used nowadays loosely in the context of this application, the ultimate objective of virtual tests is to replace partly or fully rig and engine tests during the design and certification of engines. In the past few decades, significant developments have been achieved in the discretisation methods and the associated CFD algorithms. Combined with the rapid developments in hardware in both speed and memory which are becoming increasingly available at affordable prices, the simulation of full engine or rig tests are increasingly becoming a reality. This paper describes a method by which virtual tests can be conducted on a low pressure compression system of a gas turbine engine using smart boundary conditions and allowing the sweep along a speed characteristic or sweep along a working line during the mapping of the compressor characteristic in a similar fashion to a typical rig test. The low pressure compression system is equipped with a variable downstream nozzle and the rotational speed is allowed to vary during the computations. The simulations are validated using NASA rotor 67 experimental data against which good agreement was obtained.","PeriodicalId":183819,"journal":{"name":"NAFEMS International Journal of CFD Case Studies","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124535449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Numerical Simulation of Roughness Effects Inside a Brick-lined Cyclone Separator 砖衬旋风分离器内部粗糙度效应的数值模拟

NAFEMS International Journal of CFD Case Studies Pub Date : 2011-03-01 DOI: 10.59972/x2bpsrlk

D. Kahrimanović, S. Pirker, G. Aichinger, F. Plaul

{"title":"Numerical Simulation of Roughness Effects Inside a Brick-lined Cyclone Separator","authors":"D. Kahrimanović, S. Pirker, G. Aichinger, F. Plaul","doi":"10.59972/x2bpsrlk","DOIUrl":"https://doi.org/10.59972/x2bpsrlk","url":null,"abstract":"An industrial cyclone used for separating dust from a hot gas mixture was studied by means of numerical simulation. Because of the high gas temperatures (about 1075 K), the inner surfaces of the cyclone separator and the inlet pipe must be lined with refractory bricks, causing high wall roughness. The virtual wall model was used to simulate this roughness, and a new model extension accounting for joints between the bricks is proposed and validated experimentally. As the cyclone inlet mass load was relatively low (0.01 kg/kg), the Eulerian-Lagrangian approach was used for the simulations. The continuous phase conservation equations were solved in the Eulerian reference frame on a fixed grid, whereas the discrete phase properties were determined by computing particle trajectories through the computational domain in a Lagrangian reference frame. Besides inlet particle diameters ranging from 1 μm to 100 μm, different particle materials with varying particle densities had to be considered. The measurements and the Muschelknautz analytical model were compared to the numerical simulations regarding pressure loss, particle spectra at the outlet, and the fractional separation efficiency. The Muschelknautz model exhibited some difficulties with the kind of wall roughness considered here (especially joints between bricks). Moreover, this method was not designed to handle multiple different particle densities simultaneously. Nevertheless, comparisons show good agreement between numerical simulations, measurements and theoretical predictions.","PeriodicalId":183819,"journal":{"name":"NAFEMS International Journal of CFD Case Studies","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133019025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simulation of the Efficiency of Static Mixers 静态混合器效率的仿真

NAFEMS International Journal of CFD Case Studies Pub Date : 2011-03-01 DOI: 10.59972/7gwrrmm7

J. Schöck, F. Muggli, S. Hirschberg

{"title":"Simulation of the Efficiency of Static Mixers","authors":"J. Schöck, F. Muggli, S. Hirschberg","doi":"10.59972/7gwrrmm7","DOIUrl":"https://doi.org/10.59972/7gwrrmm7","url":null,"abstract":"Within the Sulzer Corporation the behavior and efficiency of static mixers is predicted by means of CFD. Typical mixers are the SMX mixer and the CompaX mixer. As the SMX mixer is used for laminar mixing and homogenization of high viscous fluids, the CompaX mixer is applied for turbulent flow regimes. Simulations carried out for these mixers have been validated with measurements. Key values to evaluate the efficiency are the pressure loss and mixing quality. The pressure loss for both mixer types can be directly gained from the CFD simulation. But it is not possible to predict the mixing quality of laminar mixers directly from CFD simulations as for laminar flows the numerical diffusion is significantly higher than the real molecular diffusion. Thus, to predict the mixing quality of laminar mixers a trajectory method is applied. The molecular diffusion along the trajectories is taken into consideration by a Monte Carlo method. For turbulent flows diffusive mass transfer plays only a minor role. Therefore, the mixing quality can be gained directly from the CFD simulation. Furthermore, for structural analysis the forces acting on the mixer elements induced by the flow, the residence time distribution of fluid elements in the mixer and heat exchange with the duct wall is of particular interest.","PeriodicalId":183819,"journal":{"name":"NAFEMS International Journal of CFD Case Studies","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124850146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simulation of the Temperature Distribution in Automotive Head Lamps 汽车前照灯温度分布的仿真研究

NAFEMS International Journal of CFD Case Studies Pub Date : 2011-03-01 DOI: 10.59972/2u541r2q

A. Wenzel, Carsten Horn, J. Scheuchenpflug

{"title":"Simulation of the Temperature Distribution in Automotive Head Lamps","authors":"A. Wenzel, Carsten Horn, J. Scheuchenpflug","doi":"10.59972/2u541r2q","DOIUrl":"https://doi.org/10.59972/2u541r2q","url":null,"abstract":"The design of head lamps plays an important part in the development process of modern cars as it contributes significantly to the first impression of a car. However, beyond the design aspect technical requirements have to be fulfilled. These are foremost the lighting properties, the quality of the product and its lifetime. In this respect, the knowledge of the maximum temperature of different components of the head lamp is of great importance during the development process, as the temperature limits of the various materials are not to be exceeded. Therefore, numerical simulation is an important tool for the prediction of temperature distributions in head lamps during the development process. The heat transfer in an automotive head lamp is a complicated process, as different mechanisms have to be taken into account. These are the conduction in the solid parts and the transport due to convection by the air, respectively. Furthermore, heat transport due to thermal radiation plays a dominant role. Together with Audi AG, Merkle & Partner has investigated a method to predict the temperature distribution in a head lamp by means of numerical simulation. Therefore we use Star-CD for the computation of the convective flow field and the software AURA for the calculation of the radiation heat transfer. Both codes are coupled by user-subroutines. Within this paper we want to briefly describe the methodology of the process. As an example a simplified model of an automotive head lamp is investigated. The influence of the different heat transfer mechanisms is described.","PeriodicalId":183819,"journal":{"name":"NAFEMS International Journal of CFD Case Studies","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116662469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1