CFD技术在汽车工程领域中的应用研究

介绍了计算流体力学在汽车工程领域的应用概况,重点叙述了汽车CFD技术在外流场、发动机、空调系统及气动噪声等领域中的研究进展,指出了在汽车CFD技术研究中需进一步解决的问题,并展望了其发展趋势和应用前景。     

CFD方法在流体机械设计中的应用

为了计算低速到超音速的无粘和粘性流动 ,综合CFD方法当前的研究成果 ,编制了CFD通用程序并且应用于流体机械的分析与设计。几个实例表明 ,该程序是有效的 ,具有较高的工程应用价值     

CFD软件在对旋式轴流风机数值模拟中的应用

综合分析介绍了CFD软件在叶轮机械数值模拟中的两个关键问题,即数值算法和湍流模型及其最近的一些研究进展,并以对旋式轴流风机的数值模拟为例对其应用进行了举例说明,最后对CFD在叶轮机械数值模拟中的应用及发展趋势进行了展望.     

CFD在柴油机螺旋进气道位置误差分析中的应用研究

以实际发动机产品气道为研究对象,使用三维流体动力学软件Fire完成了气道稳流试验台中气道—气缸流动的三维流场数值模拟计算,分析了气道上下平移和倾斜对气道性能的影响规律,结果与采用气道试验方法的结果吻合良好。     

CFD技术在化工机械设计中的应用

在化工机械设计中引入CFD技术,这种引入的技术在化工机械行业已经日益发展起来。本文将对CFD数字模拟技术的特点进行介绍,举例说明CFD技术在化工机械设计中的应用技术,以求让读者了解使用CFD技术解决化工问题的求解过程,为读者了解和研究化工机械模拟做下铺垫。     

计算机模拟与预测方法在材料科学研究中的应用

计算机模拟与预测方法在材料科学研究中得到愈来愈广泛的应用。针对材料研究的发展趋势,介绍了常用的有限元法、有限差分法、蒙特卡罗方法、分子动力学方法及人工神经网络方法等的特点,并列举了它们在材料研究开发中的应用。     

激光在材料加工中的新应用

本文着重阐明激光冲击波处理、激光表面合金化处理、小功率CO_2激光器在材料加工中的特殊用途以及激光材料加工的前景。     

材料热加工工艺模拟的研究现状及技术发展趋势

１开展热加工工艺模拟研究的重大意义（１）使热加工由定性→定量;“技艺”→“科学”热加工兼有成形、改性两个功能高温、动态、瞬时,难于观察、测试多因素、强耦合、非线性、非稳态,难以用理论定量模拟过程,预测结果,优化设计（２）具有重要应用背景及重大效益力保...     

CFD在柴油机螺旋进气道评价中的应用

本文用CFD软件对直喷柴油机螺旋进气道进行了三维数值模拟；通过气道稳流试验台对模拟计算得到的Ricardo和FEV评价参数进行了验证，得出两者趋势吻合良好的结论；指出了CFD在评价柴油机螺旋进气道性能中的实用价值。     

CFD在吹风冷却装置设计中的应用

讨论将CFD技术引入到吹风冷却装置中去。通过对吹风冷却装置实例利用CAD／CAM软件UGⅡ和CFD软件FLUENT相结合,进行气流场模拟,结合实验测试,在验证仿真模拟方法的基础上,对吹风冷却装置的设计进行了有效的改进。     

Analysis of viscosity effect on turbine flowmeter performance based on experiments and CFD simulations

Viscosity effect is one important factor that affects the performance of turbine flowmeter. The fluid dynamics mechanism of the viscosity effect on turbine flowmeter performance is still not fully understood. In this study, the curves of meter factor and linearity error of the turbine flowmeter changing with fluid viscosity variations were obtained from multi-viscosity experiments (the viscosity range covered is 1.0×10^–6 m²/s–112×10^–6 m²/s). The results indicate that the average meter factor of turbine flowmeter decreases with viscosity increases, while the linearity error increases. Furthermore, Computational Fluid Dynamics (CFD) simulation was carried out to analyze three-dimensional internal flow fields of turbine flowmeter. It was demonstrated that viscosity changes lead to changes of the wake flow behind the upstream flow conditioner blade and the flow velocity profile before fluid entering turbine rotor blade, which affect the distribution of pressure on the rotor blades, so impact the turbine flowmeter performance.     

基于CFD的风冷摩托车发动机气缸体的传热仿真研究

针对单缸风冷摩托车发动机气缸体的传热问题,基于热力学第一定律建立了进气过程中气缸壁传热量的数学模型,分析了气缸周壁的传热方式,通过CAD三维软件建立了发动机气缸体的三维模型,并进行计算网格划分,给定边界条件,应用计算流体力学( CFD)软件对发动机气缸体传热过程进行数值模拟计算,得出气缸体的温度分布图,从而获得气缸壁传给进气气体的热量值,为进一步研究摩托车发动机气缸体的传热问题提供参考.     

基于CFD数值模拟的中冷器导流装置性能研究

基于计算流体力学(Computational Fluid Dynamics)方法,对某款中冷器导流装置的分配性能进行研究。把中冷器在有、无导流装置作用时的数值模拟结果作比较,定性和定量分析导流装置对中冷器芯子流道间流体均匀分配的作用,并进一步分析了质量流量变化对导流装置分配作用的影响。结果发现,导流装置能显著提高中冷器的流体分配的均匀性;同时增加导流装置以后,对中冷器的压降不会带来较大的增加,不会影响整车的油耗。研究结果为进一步改进中冷器的气室结构,改善中冷器的流动分配的均匀性提供必要的理论依据。     

车用涡轮流量计叶轮的有限元分析

主要阐明了对车用涡轮流量计的机械结构进行有限元分析的过程,结合分析结果对涡轮流量计的叶片造型参数提出改进方案.首先使用Catia软件对流量计机械结构和管道中的流体进行建模,然后导入ANSYS CFX进行流体分析,得出仿真结果后,经过对比确定叶片的造型参数,使得流量计计量精度提高.     

The effect of blade angle on the flow and pressure distributions in the vicinity of the diffuser blades of a room air conditioner

Many studies on air-conditioning systems are more focused on the individual thermal comfort rather than the thermal efficiency, due to an increase in health concerns. There are several factors influencing the thermal comfort, such as temperature, humidity, convection and air movement, etc. Numerical analyses were performed to investigate the effect of blade angle on the flow characteristics in the vicinity of diffuser blades of a room air conditioner (RAC), with three different blade discharge angles of 45.1°, 58.6° and 116°. We used the commercial code FLUENT to calculate the two-dimensional steady thermal flow fields with different impeller rotational velocities. The angular velocities were located within the range from 900 rpm to 1200 rpm. Turbulence closure was achieved using a standard k-ɛ model. A moving reference frame (MRF) approach was adopted to simulate the flow field generated by the impeller in an RAC. The results were graphically depicted with various geometrical configurations and operating conditions. This paper was presented at the 7th JSME-KSME Thermal and Fluids Engineering Conference, Sapporo, Japan, October 2008. Youn-Jea Kim received his B.S. degree in Mechanical Engineering from Sungkyunkwan University, Korea, in 1982. He then received his M.S. and Ph.D. degrees from the State University of New York at Buffalo in 1987 and 1990, respectively. Dr. Kim is currently a Professor at the School of Mechanical Engineering at Sungkyunkwan University in Korea. Dr. Kim’s research interests include gas dynamics, MEMS, and fluid-machineries, etc.     

Pulsatile blood flows through a bileaflet mechanical heart valve with different approach methods of numerical analysis; pulsatile flows with fixed leaflets and interacted with moving leaflets

Many researchers have investigated the blood flow characteristics through bileaflet mechanical heart valves using computational fluid dynamics (CFD) models. Their numerical approach methods can be classified into three types; steady flow analysis, pulsatile flow analysis with fixed leaflets, and pulsatile flow analysis with moving leaflets. The first and second methods have been generally employed for two-dimensional and three-dimensional calculations. The pulsatile flow analysis interacted with moving leaflets has been recently introduced and tried only in two-dimensional analysis because this approach method has difficulty in considering simultaneously two physics of blood flow and leaflet behavior interacted with blood flow. In this publication, numerical calculation for pulsatile flow with moving leaflets using a fluid-structure interaction method has been performed in a three-dimensional geometry. Also, pulsatile flow with fixed leaflets has been analyzed for comparison with the case with moving leaflets. The calculated results using the fluid-structure interaction model have shown good agreements with results visualized by previous experiments. In peak systole, calculations with the two approach methods have predicted similar flow fields. However, the model with fixed leaflets has not been able to predict the flow fields during opening and closing phases. Therefore, the model with moving leaflets is rigorously required for advanced analysis of flow fields.     

正弦波纹流道中流体流动和传热特性研究

采用计算流体力学(CFD)方法,研究了一定雷诺数范围内(50≤Re≤200),正弦波纹流道内的流体充分发展的层流流动和传热性能。比较了不同结构的正弦波纹流道的阻力因子ef、传热因子eNu和能效因子e的值,研究结果表明,正弦波纹流道的波纹波幅对于流体流动和传热性能的影响较大。分析了波纹流道中垂直于主流方向特殊横截面上的流体速度矢量图和温度等值线图,研究结果表明,波纹流道的弯曲壁面使得流体在流道中垂直于主流方向的截面上产生二次流,二次流的出现增强了流道中心流体和近壁处流体的混合和传热,传热性能提高的同时阻力增加。     

Numerical analysis of a weak shock wave propagating in a medium using lattice boltzmann method (LBM)

This study introduced a lattice Boltzmann computational scheme capable of modeling thermo hydrodynamic flows with simpler equilibrium particle distribution function compared with other models. The equilibrium particle distribution function is the local Maxwelian equilibrium function in this model, with all the constants uniquely determined. The characteristics of the proposed model is verified by calculation of the sound speeds, and the shock tube problem. In the lattice Boltzmann method,a thermal fluid or compressible fluid model simulates the reflection of a weak shock wave colliding with a sharp wedge having various angles θ_w. Theoretical results using LBM are satisfactory compared with the experimental result or the TVD.