车用散热器百叶窗布置方式的数值模拟与分析

针对车用百叶窗翅片式散热器的传热和流阻特性,采用数值模拟计算方法对百叶窗对称布置和非对称布置2种方式的散热器进行了研究分析,通过计算百叶窗翅片空气侧的传热量、传热因子和压降,以及散热器综合性能评价因子,获得了综合性能较优的百叶窗布置形式.结果表明,在相同的进出口边界和给定的几何参数条件下,对称布置的百叶窗翅片具有较高的传热性能,但流阻性能较差.当空气入口速度为5.58,m/s时,与非对称形式相比,对称布置时的传热量提高了14.7%,压降却增加了29.3%;在不同的空气入口速度条件下,对称布置时百叶窗翅片具有较高的散热器综合性能评价因子,因此,百叶窗对称布置时散热器综合性能较好.

Numerical Simulation and Analysis of Different Louver Arrangements of Automotive Heat Exchangers

Numerical simulation investigation and analysis of heat transfer and flow resistance performance over lou- vered fins in automotive heat exchangers were presented. Three-dimensional simulations on the air-side were per- formed for two types of louvered fin configurations i. e. symmetrical arrangement and asymmetrical arrangement. Calculated results reflected by air-side heat transfer rate, heat transfer factor and pressure drop, along with compre- hensive evaluation factor, indicated that a symmetrical arrangement of louvered fins provided an increase in heat transfer performance and also an increase in pressure drop compared with the asymmetrical arrangement of louvered fins under the same inlet and outlet boundary conditions for the given geometrical parameters. At the air frontal veloc- ity of 5.58 m/s, the heat exchangers with symmetrical arrangement of louver provided a 14.7% increase in heat trans- fer rate but also a 29.3% increase in pressure drop compared with the asymmetrical arrangement of louver. And for different air frontal velocities, the comprehensive evaluation factor for symmetrical arrangement of louvered fins are higher than that of the asymmetrical arrangement. The results indicate that the overall performance is better for heat exchangers with symmetrical arrangement of louver.