基于灵敏度分析-中心组合设计的乘用车发动机舱温度场优化

Optimization of Car Underhood Temperature Field Based on Sensitivity Analysis and Central Composite Design

针对某乘用车传动轴护套表面温度超标问题,基于灵敏度分析和中心组合设计方法对其发动机舱的温度场进行优化。首先,对发动机舱进行CFD仿真分析找出问题原因;然后,通过灵敏度分析找出主要影响因素;接着,采用中心组合设计和二次多项式回归方程建立传动轴护套表面温度预测模型,并找出主要影响因素的最优组合;最后,进行仿真和实车试验验证。结果表明:护套表面温度降低到限值以下,有效解决了其温度超标问题。

Aiming at the overheat problem of a car driving shaft shroud, an optimization on the temperature field in engine compartment is conducted based on sensitivity analysis and central composite design method. Firstly, the CFD simulation of engine compartment is performed to find out the causes. Then, the main influencing factors are found by sensitivity analysis. Next, model for predicting the surface temperature of driving shaft shroud is established using central composite design method and quadratic regression equation, and the optimal combination of main influencing factors are found. Finally simulation and real vehicle test are carried out for verification. The results indicate that the surface temperature of driving shaft shroud reduces to below the limit value, effectively solving its overheat problem.