浙江科技学院学报

In order to explorethe flow pattern and the coupled heat transfer characteristics of external airflow field and internal fluid flow of the engine radiator, an engine cooling system test-bed was built and the 465Q engine ribbon-tubular radiator was selected for an experimental research. The axial velocity distributions on the surface of the radiator and the outlet of the wind duct were obtained by measuring andcalculating the static pressures of each 15 measuring points on the front and the back of the radiator, as well as the total pressures, the static pressuresand thefan shaft powers of 8 measuring points on the wind duct outletat 8 kinds of fan rotational speed. At the same time, the study synchronicallymeasured the physical parametersof the radiator, such aspressuresand temperatures at the inlet and the outlet, and conducted the frontal thermographyof the radiator, under the definite conditions of influent flow qv=1.8 m3/h and inlet water temperature t1=85 ℃. The study then plotted curves of the surfacepressure, the velocity distribution, as well as the heat transfer characteristicsofthe radiator changing with variable fan speed, and fitted a series of function equations. The results show that with the increase of fan speed, the airflow rate and the average airflow velocity increases, the heat dissipation tends to increase at first and then decrease. The analysis data shows that the average airflow surface velocity and the heat dissipation of the radiator approximately meet the similar conversion relationship of 1.7 times.