新型2D25卧式柴油机冷却水套CFD分析

CFD Analysis of Cooling Jacket in New Type of Horizontal Diesel Engine

针对新型2D25卧式柴油机冷却水套结构,采用NX5.0软件建立了冷却水套三维分析模型,并应用CFD软件AVL-FIRE,对冷却水套进行三维流动仿真计算,详细分析了冷却水套速度场、换热系数分布、流量分布、压力损失等流场特征。结果表明,该两缸柴油机冷却水套整体水流平均速度约为0·8m/s,基本能够满足设计要求;缸体、缸盖处水流平均速度分别为0.898m/s、0.67m/s,但从换热系数、缸盖上水孔流量及截面速度看,该冷却水套各缸冷却不均、局部存在流动死区,有待进一步改进。

With the CFD software FIRE from AVL,3D flow simulation calculation of cooling jacket of the new- developed two-cylinder horizontal engine is performed. Flow field characteristics, such as flow velocity field, HTC （heat transfer coefficient distributions）, mass flow distributions and pressure losses in the cooling jacket are analyzed specifically. Results demonstrate that the overall flow average velocity of this two-cylinder cooling jacket is about 0. 8 m/s, assuring to be able to basically meet the design requirements. Average folw velocity in the Cylinder block is 0.898 m/s. It＇s 0. 67 m/s in the cylinder head. But according to HTC, mass flow of water passing holes and velocity slices of the cylinder head, cooling characteristics of the two cylinders are uneven, there exist stagnation zones in local regions. The structure of cooling jacket needs to be improved.