冷却管结构及进气方向对空冷中冷器性能的影响

Influence investigation of cooling tube structure and airflow direction on thermal-hydraulic performance of air-cooled charge air cooler

首先,通过试验方法获得了基准空冷中冷器在不同速度时的冷侧静压降和传热系数。然后,采用计算流体力学方法对试验值进行了验证,结果表明,对于静压降,试验值与仿真值的绝对误差不超过7%,而传热系数则不超过15%,说明当前仿真的准确性。接着,继续采用计算流体方法研究了冷侧风速为6 m/s时,不同冷却管前缘半径R_(1)及进气方向β对空冷中冷器冷侧热工水力性能的影响,结果表明,当R_(1)=3.6 mm且β=90°时,Fanning摩擦因子f取得各工况中的最小值;当R_(1)=0 mm且β=90°时,努赛尔数Nu取得各工况中的最大值;当R_(1)=3.6 mm且β=90°时,中冷器热工水力性能综合评价准则PEC取得各工况中的最大值。

In this paper, the static pressure drop and heat transfer coefficient of the cold side of the benchmark air-cooled Charge Air Cooler(CAC) at different speeds are obtained through experimental methods. Then the experimental values are verified by computational fluid dynamics methods. Results show that for the static pressure drop, the absolute error between experimental values and simulation values is less than 7%, and for heat transfer coefficient the error is less than 15%, which indicates the accuracy of the current simulation. After the validation, computational fluid dynamics method was applied to investigate the influence of the leading edge radius R_(1)of the cooling pipe and the airflow direction β on the cold side thermal and hydraulic performance of the CAC under the airflow speed of 6 m/s. Research results show that, when R_(1)=3.6 mm and β=90°, the Fanning friction factor f achieves the minimum value in each working condition;when R_(1)=0 mm and β =90°, Nusselt number Nu reaches the maximum value in all working conditions;and when R_(1)=3.6 mm and β =90°, the Performance Evaluation Criterion(PEC) for the thermal and hydraulic performance of the CAC obtaines the maximum value in each working condition.