Abstract: In order to ensure that the vehicle cooling performance meets the development target,now more car companies use environmental wind tunnels to complete relevant development work in the laboratory,which not only ensures the consistency of verification standards,but also greatly shortens the development time and cost. However,it is undeniable that the external air temperature,humidity,wind speed,sunshine and other environmental parameters simulated by the environmental wind tunnel are different from the actual driving environment of the vehicle. By using vehicle offset to simulate the external environment,the air flow and cooling performance of a side radiator of a minibus were compared when the vehicle was normal and offset,and the test differences caused by the size limitation of the nozzle of the environmental wind tunnel were clarified. Moreover,the evaluation results under the actual external use environment were predicted through data correction in the subsequent vehicle development.

Key words: cooling performance, environmental wind tunnel, wind volume of radiator