摘要
空气滤清器是内燃机进气系统的重要部件,直接影响内燃机性能。提高空气滤清器内气流速度分布均匀性,降低压力损失,是提高其滤清效率、延长其使用寿命的重要措施,也是空气滤清器结构设计的关键。应用先进的三维数值计算技术可以获得空气滤清器内部流场详细信息,得到其综合评价结果,为空气滤清器结构优化设计提供重要的理论依据。
应用多孔介质模型模拟了空气滤清器粗滤器内的丝网和精滤器内的滤芯,建立了空气滤清器内部流动数学模型。利用Pro/Engineer建立了空气滤清器三维几何模型,利用STAR-CD前处理器Pro/am生成了其流场三维非结构化计算网格。
在确定初值、边界条件后,应用STAR-CD求解器STAR较详细地计算了空气滤清器内部流场,利用压力云图和速度矢量分布图等进行了内部流场显示,得到了速度场、压力场的分布规律。结果表明:气流对空气滤清器入口部分拐角处产生了强烈冲击,出口处的速度分布不均匀;空气滤清器内部存在明显涡流,造成较大的压力损失。
分析计算了空气滤清器入口处壁面圆弧大小对其压力分布、速度分布的影响。在此基础上,对空气滤清器入口处进行了结构优化设计,以圆弧结构取代原直线结构。结构优化前后的计算分析结果表明:优化后入口部分内部流场速度分布均匀性提高了10%,进出口压力损失降低了32%。
As an important component of the internal combustion engine intake system, the air filter has directly effect on its performances. The improvement of the flow velocity distribution and the reduction of the pressure loss are helpful to increase air filter filtration efficiency and prolong its service time, and they are also the keys to design air filter. With advanced three-dimensional numerical simulation technology,the detail flow filed in the air filter can be obtained, and the overall evaluation can be gotten, and the important theoretical foundation can be provided for the structure optimization of the air filter.
The mesh in the preliminary filter and the fibre core of the fine filter are simulated with a porous medium model, and then the mathematical model of the flow in air filter is set up. The three-dimensional geometry models of the air filter are made by Pro/Engineer, and the numerical simulation computation grids of the flow field in air filter are generated by STAR-CD pretreatment tool Pro/am.
Based on STAR-CD, the simulation of the flow field in the air filter is carried out more detailed after the initial and boundary values are determined. The flow field visualization is done with the pressure atlas and velocity vector, the pressure and velocity distributions are gotten. The results show that the flow had a strong impact on the entrance corner of air filter inlet part, the velocity distribution of the exit is uneven, and the vortexes exist in air filter, so that it caused greater pressure loss.
The influences of inlet box arc in inlet of the air filter on the pressure and velocity distributions are simulated and analyzed, and then the inlet box shape of the air filter is optimized using the arc structure to replace the original linear structure. The optimization results show that the velocity distribution uniformity is enhanced 10% and the pressure loss is reduced 32% after the structure optimized.
引文
[1] 陈晓玉.摩托车空气滤清器性能检测方法探讨[J].摩托车技术, 2005(7): 25-26
[2] Fodor J. Improving the Economy of I. C. Engine Life by Controlling the Contaminants Through Filtration [A]. World Filtration Congress Ⅲ[C].1982: 77-80
[3] Fodor J. Improving Utilization of Potential I. C. Engine Life by Filtration [J]. tribology Intimation, 1979(12): 127-129
[4] 葛蕴珊.进气灰尘对柴油机磨损的实验研究[J].内燃机工程, 1997(1): 57-60
[5] 12150 柴油机编写组.12150 柴油机[M].北京: 国防工业出版社, 1976: 124-150
[6] 高雪莲.基于三维紊流计算的空气滤清器性能分析[D].北京: 北京理工大学, 2003
[7] 吴一敏.车用空气滤清器的现状及其发展趋势汽车研究与开发[J].汽车研究与开发, 1999(4): 42-51
[8] 高延奎.浅谈汽车发动机进气系统空气滤清器的设计[J].辽宁交通科技,2005: 99-100
[9] Bugh N. Filtration Challenges and Conical Filter Development for Engine Air Induction System [J]. SAE Paper, 1995(9): 41-45
[10] Barras M. Total Filtration TM: The Influence of Filter Selection on Engine Wear, Emission, and Performance [J]. SAE Paper, 1995(2):55-57
[11] 沈俊.CFD 在汽车空气动力学设计中的应用[J].汽车技术, 2000(10): 1-3
[12] 李明华,魏名山,马朝臣.静电旋风微粒捕集器的研究现状及其在柴油机上的应用[J].铁道机车车辆, 2003(23): 23-26
[13] 王洪斌.JDL-3080 型收获机空气滤清器的改装[J].现代化农业, 2006(3): 38
[14] 乔瑞东, 张俄文.贝拉斯矿用汽车空气滤清器的改进[J].矿用汽车, 2000(3): 27-30
[15] 张东育,宋学文.关于风沙地区 DF4 型机车空气滤清器的改进[J].内燃机车, 2003(9): 34-35
[16] 雷银霞.机车用新型空气滤清器的研制[J].内燃机车, 2003(4): 15-17
[17] 阎为革, 刘淑艳, 黄虹宾.一种新型车用空气滤清器的研究[J].北京理工大学学报, 2002(10): 23-25
[18] 黄佑生, 孙茂棠, 刘闽京.高速旋转式动态空气滤清器[J].北京理工大学学报, 2000(2): 55-59
[19] 高雪莲, 王国玉, 刘淑艳等.旋转自洁式空气滤清器内部气固两相流场的计算与分析[J].北京理工大学学报, 2003(23): 44-48
[20] 刘淑艳, 徐永强, 阎为革等.旋转自洁式空气滤清器结构选择的试验研究[J].车辆与动力技术, 2001(4): 8-12
[21] A.Al-Sarkhi. Optimization techniques for design of automotive air filter housings with improved fluid dynamic performance and filtration [J]. Particulate Science and Technology, 2004(22): 47-50
[22] 黄虹宾, 刘淑艳.郑世琴等.二级空气滤清器中旋风分离器流场的数值模拟[J].内燃机学报, 1999(17): 82-86
[23] Bugh N J.发动机进气系统空滤器的性能要求[J].国外内燃机, 1999(1): 14-24
[24] Rikke k. Byskov, Christina B. Jacobsen. Flow in a centrifugal Pump Impeller at Design and Off Design Conditions—PartⅡ[J]. Large Eddy Simulations Journal of Fluids Engineering, 2003(22): 25-73
[25] 姚征,陈康民.CFD 通用软件综述[J].上海理工大学学报, 2002(2): 43-50
[26] 孙庆宽,王硕.STAR-CD 软件在家用空调产品开发中的应用[J].家电科技, 2004(4): 49-54
[27] STAR-CD New User Training [Z]. CD adapco Group
[28] 韩艳霞.计算流体力学通用软件 STAR-CD简介[J].甘肃科技, 2005(9): 42, 76
[29] 谭洪卫.计算流体动力学在建筑环境工程上的应用[J].暖通空调, 1999, 29(4): 31-36
[30] Chen C-J, Jaw S-Y. Fundamentals of turbulence modeling [J]. Washington DC, Taylor& Francis, 1998. X I: 91-92, 119, 69,71,63,64
[31] 窦国仁.湍流力学[M].北京: 高等教育出版社, 1985:232-280
[32] Anderson D A, Tannehill J C, Pletcher R H. Computational fluid mechanical and heat transfer [M]. Washington DC: Hemisphere, 1984: 199-201
[33] Markatos N C, The mathematical modeling of turbulence flows[J]. Appl math modeling, 1986(10): 190-220
[34] Ferziger J H. High-level simulation of turbulence flows [J]. In: Essers J A, ed. Computational methods for turbulent flows, transonic and viscous flows. Washington DC: hemisphere, 1983: 93-182
[35] Orszag S A. Numerical simulation of turbulence flows [J]. Frost W, Moulden T H, eds. Handbook of turbulence. New York: Plenum Press, 1977: 281-313
[36] Moin P, Mahesh K. Direct numerical simulation: a tool in turbulence research [J]. Ann Rev Fluid Mech. 1998(30): 39-78
[37] Moin P, Kim J. Numerical investigations of turbulent channel flow [J]. J Fluid Mech, 1982: 341-344
[38] Chapman D R. Computational aerodynamics development and outlook [J]. AIAA J, 1979(17): 1293-1313
[39] 蔡树棠, 刘宇陆.湍流理论[M].上海:上海交通大学出版社, 1993: 152,145
[40] ANSYS. Modeling and Meshing Guide [Z]. Release5.5, 1997
[41] Bas ven den Heuvel. In-Cylinder Flow Analysis for Production-Type Internal Combustion Engines [J].Printed in the Netherlands, 1998: 34-37
[42] D.B.Spalding.Lectures in Mathematical Models of Turbulence [A]. Academic Press: London, England[C].1972: 82-85
[43] STAR-CD Methodology [Z]. Computational Dynamics Limited, 2001
[44] 吴子牛.计算流体力学[M].北京: 科学出版社, 2001: 83-92
[45] Girault V, Raviart P A. Finite element methods for Navier-Stokes equations[J]. Berlin Springer, 1986(10): 57-61
[46] 张涵信, 沈孟育著.计算流体力学差分方法的原理和应用[M].北京: 国防工业出版社, 2003: 50-76
[47] 金忠青.N-S 方程的数值解和紊流模型[M].南京: 河海大学出版社, 1989: 56-63
[48] 陈作斌.计算流体力学及应用[M].北京: 国防工业出版社, 2003: 109-119
[49] 张涵信, 贺国宏, 张雷.高精度差分求解气动方程的几个问题[J].空气动力学报, 1993,11(4): 347-356
[50] LiuX, Osher S, Chan T. Weighed Essentially Non-Oscillatory Shock Capturing Schemes [J]. J. Comp. Phys.1994 (11): 200-212
[51] 王福军.计算流体动力学分析 CFD 软件原理与应用[M].北京: 清华大学出版社, 2004: 63-105
[52] 刘碧俊.基于 Pro/E 的仿形靠模三维造型设计[J].现代制造工程, 2007(1): 63-64
[53] Thompaon Joe F. A reflection on d generation in the 90s: trends, needs, and influences [A]. In: 5th International Conferences on Grid Generation in Computational Field Simulation[C], 1996: 106-109
[54] 陶文铨.计算传热学的近代进展[M].北京: 科学出版社, 2000, 431-452
[55] Steven J. Owen. Non Simplical Unstructured Mesh Generation [J]. The Department of Civil and Environmental Engineering Carnegie Mellon University, 1999(4): 8-33
[56] Chris L, Jackins, Steven L, et a1. Oct-Tree and Their Use in Representing Three-Dimensional Objects [J]. Computer Graphics and Image Processing, 1980(14): 249-269
[57] 龚光彩, 张文宏, 孙培雷.网格自动生成技术进展综论[J].建筑热能通风空调, 2006(2): 29-34, 77
[58] Sumit R. Maloo. A Rule-Based Approach to Quadrilateral Mesh Generation [J]. The Master of Science Degree in Industrial Engineering, 2001(10): 1-21
[59] STAR-CD Version 3. 26 Tutorial Manual, 2005
[60] Biswas R, Strawn R C. Tetrahedral and hexahedral mesh adaptation for CFD problems [J]. Applied Numerical Mathematics, 1998, 26(1): 135-151