某改型汽油机机体热负荷分析

通过建立的气缸盖、机体和冷却水耦合计算模型,使用直接耦合法,利用CFD软件计算了机体温度场。计算结果显示,将汽油机原有的2气门配气机构改为4气门后,随着热负荷的加大,机体最高温度升高了22.1℃。并以此温度场为边界条件,利用FEA软件计算了机体热应力和热变形。结果表明,在只有热负荷作用时,改型后机体受到的最大热应力由51.0 MPa增加到60.2 MPa,最大热变形由0.27 mm增加到0.37 mm。

Analysis on Thermal Load of a Modified Gasoline Engine Cylinder Block

Directly coupled simulation is employed in this paper to investigate the temperature field of cylinder block in a 4-valve gasoline engine by using of CFD software.Computational model includes cylinder head,cylinder block and water jacket.After the valve train is changed from 2 valves to 4 valves.The CFD result shows that for thermal load enhance,the highest temperature of cylinder block increase 22.1 ℃.Then,the temperature field is loaded in FEA software to predict thermal stress and deformation.The FEA result reveals that the maximum thermal stress of cylinder block increases from 51.0 MPa to 60.2 MPa.The maximum thermal deformation increase from 0.27 mm to 0.37 mm.