直背式小轿车外流场数值模拟摘要随着人们生活水平的提高、建造高速公路水平的提高,人们驾驶汽车的车速就有了明显增加,这使得对汽车空气动力学的研究变得极为重要。气动阻力和气动升力的研究不仅可以提高汽车的性能,同时可以减少能源的消耗和提高提车的安全性,具有重大的经济意义。传统的空气动力学研究是采用风洞试验,但是这种研究成本高、周期长。随着计算机技术和计算流体力学(CFD)的发展,汽车空气动力学研究中运用CFD技术极大的减少了成本和周期。本文采用CFD方法对长安某型汽车进行了汽车外流场研究。对其汽车进行适当建模,研究它的外流场特性,得到在不同速度下的气动阻力和气动升力。本课题采用Workbench软件对长安某型汽车以1:1比例建立简单三维模型,并画出流场域,采用ICEM对其进行分块网格划分。运用Fluent软件对其进行汽车外流场数值模拟,分析它的气动阻力特性、气动升力特性和流动情况。关键词:空气动力学特性计算流体力学网格划分流场ABSTRACTWiththeimprovementofpeople'slivingstandard,therapiddevelopmentofexpresswayandtheincreaseofvehiclespeed,itisverynecessarytostudytheaerodynamiccharacteristicsofautomobile.Thestudyofaerodynamicdragandaerodynamicliftcannotonlyimprovetheperformanceofthecar,butalsoreducetheenergyconsumptionandimprovethesafetyofthecar.ThetraditionalaerodynamicsresearchUSESwindtunneltest,butthiskindofresearchcostishigh,thecycleislong.Withthedevelopmentofcomputertechnologyandcomputationalfluidmechanics(CFD),theapplicationofCFDtechnologyinautomobileaerodynamicsresearchgreatlyreducesthecostandcycle.Inthispaper,CFDmethodisusedtostudytheautomobileoutflowfieldofacertaintypeofautomobileinchang'an.Themodelofthevehicleisproperlymodeled,andthecharacteristicsofitsoutflowfieldarestudied.Theaerodynamicresistanceandaerodynamicliftatdifferentspeedsareobtained.Inthisproject,Workbenchsoftwarewasusedtobuildasimple3dmodelforacertaintypeofautomobileinchang'anat1:1ratio,andflowfieldwasdrawn.ICEMwasusedtosegmentthegrid.Fluentsoftwarewasusedtosimulatethenumericalsimulationoftheoutflowfieldofitsmemoryvehicles,anditsaerodynamicresistancecharacteristics,aerodynamicliftcharacteristicsandflowconditionswereanalyzed.Keywords:aerodynamiccharacteristics;computationalfluiddynamics;griddivision;flowfielddivision目录摘要........................................................................................................................IABSTRACT....................................................................................................................II目录............................................................................................................................11绪论....................................................................................................................31.1研究目的及意义........................................................................................31.2国内外研究现状........................................................................................31.3论文主要工作............................................................................................52汽车空气动力学基础............................................................................................62.1气动阻力....................................................................................................62.1.1形状阻力............................................................................................62.1.2摩擦阻力...................................................................................