ABSTRACT

Many troubles appear when vehicles work in the plateau region, and the main reason is that the heat-transfer capability of radiator in the vehicle cooling system reduces under the plateau low air pressure environment. Hence, the research on the flow and heat transfer characteristics of radiators in plateau low air pressure environment is necessary. In this paper, the experimental study on the thermal-hydraulic characteristics of corrugated fin radiator is conducted on a wind tunnel test-bed with low pressure function. The results illustrate that the air-side convective heat transfer coefficient of the corrugated fins decreases with the decrease of the ambient pressure, and the Colburn factor (j) and Friction factor (f) increase simultaneously. When the gauge pressure is −44 kPa, the air-side convective heat transfer coefficient is 34% lower than that under normal pressure on average, and the Colburn factor and Friction factor increase by an average of 21.1% and 55.6%, respectively. On this basis, the entransy dissipation and field synergy angle distribution of the corrugated fin radiator under low-pressure environment are studied. It is showed that the entransy dissipation number at −44 kPa gauge pressure reduces by 65% on average. The air-side field synergy angle increases with the decrease of the ambient pressure. Finally, the experimental correlations of the Colburn factor and Friction factor are performed, and the average deviations of the calculated results are 2.8% and 3.3%, respectively.

摘要

车辆在高原地区工作会出现很多问题，主要原因是在高原低气压环境下，车辆冷却系统中散热器的传热能力降低。因此，有必要对高原低气压环境下散热器的流动和传热特性进行研究。本文在具有低压功能的风洞试验台上对波纹翅片散热器的热工水力特性进行了实验研究。结果表明，波纹翅片的空气侧对流传热系数随着环境压力的降低而降低，科尔本系数（j）和摩擦系数（f）同时增加。当表压为-44 kPa时，空气侧对流传热系数比常压下平均降低34%，科尔本系数和摩擦系数分别平均提高21.1%和55.6%。在此基础上，研究了波纹翅片散热器在低压环境下的焓耗散和场协同角分布。结果表明，-44 kPa 表压下的焓耗散数平均减少了 65%。空气侧场协同角随着环境压力的减小而增大。最后对Colburn因子和摩擦因子进行了实验相关，计算结果的平均偏差分别为2.8%和3.3%。分别。在此基础上，研究了波纹翅片散热器在低压环境下的焓耗散和场协同角分布。结果表明，-44 kPa 表压下的焓耗散数平均减少了 65%。空气侧场协同角随着环境压力的减小而增大。最后对Colburn因子和摩擦因子进行了实验相关，计算结果的平均偏差分别为2.8%和3.3%。空气侧场协同角随着环境压力的减小而增大。最后对Colburn因子和摩擦因子进行了实验相关，计算结果的平均偏差分别为2.8%和3.3%。空气侧场协同角随着环境压力的减小而增大。最后对Colburn因子和摩擦因子进行了实验相关，计算结果的平均偏差分别为2.8%和3.3%。