The distributions of axial static pressure coefficient and flow fluctuation in the test section affect aerodynamic measurement in an open jet wind tunnel. In this paper, the flow characteristics of the open jet automotive wind tunnel with passive reinjection and active reinjection were simultaneously investigated by experimental and numerical approaches. The axial static pressure coefficient variations can be reduced by passive or active reinjection, and recycle flow returns to the test section from the loophole is the main reason. The more mass flow rate, the better improvement effect. Meanwhile, it is found that the improvement of the axial static pressure coefficient by reinjection is always better in the condition of 0° collector angle. The turbulence intensity on the collector angle of 15° is lower than that of 0°, and the reinjection increases the turbulence intensity near the collector. The increase of the turbulence intensity by active reinjection in the collector angle of 0° is greater than with the collector angle of 15° for the 3.28° diffusion angle. There are some peaks emerge at the frequencies of 40 Hz and 50 Hz, which indicates that the flow field fluctuations may have induced by structure vibration. The peaks at several frequencies increase when the passive and active reinjection are conducted, and the increase of peak is correlate with the increase of the reinjection flow rate. Due to the reduction of average static pressure coefficient and increase of flow fluctuations, the application of passive and active reinjection should be considered at the same time.
کلید واژگان :The distributions of axial static pressure coefficient and flow fluctuation in the test section affect aerodynamic measurement in an open jet wind tunnel. In this paper, the flow characteristics of the open jet automotive wind tunnel with passive reinjection and active reinjection were simultaneousl
ارزش ریالی : 600000 ریال
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