翼身组合体流场测量和分析

Measurement and Analysis of the Flow Field above a Wing/Body Configuration

本文给出了翼身组合体空间流场测量结果,揭示了机身涡、机翼涡随迎角的变化及相互干扰情况。当迎角足够大时,翼面上方流态从破裂涡发展成完全分离流,其尺度可达5～8倍机身直径。

The flow patterns over a wing/body configuration at high angles of attack are very complex. There are many difficulties in numerical simulation of the complex flow with vortex burst and full separation. Thus, measurement of the flow field over a wing / body configuration is needed. This paper will introduce the measured result of the flow field above the wing/body configuration with a double delta wing. The test on a configuration with double delta wing was conducted in a wind tunnel . The leading edge swept angle of the inner and outer wing for the double delta wing are 70°/50° respectively. The test was completed in the closed retern wind tunnel with an open test section at BUAA. The test wind speed was about 15m/sec. Based on the mean aerodynamic chord of the wing, Reynolds number was about 320000. The measurement of the pressure and velocity distribution with the 7-holes probe was performed in the sections perpendicular to the axis of the wind tunnel. For each angle of attack tested, stations 2 to 5 along the axis were selected. The measurement result of the flow field shows that the flow patterns over a wing/body configuration with double delta wing at medium to large angles of attack can be attributed to the following factors, the wing leading edge vortex and the body vortex, the broken down vortex flow and the full separation flow. The body vortex appears at medium incidence. It is induced by the wing vortex with the same rotation sense and pulled into above the wing. There is a viscous interference regime with low energy near the junction of the wing-body, which is increased with larger incidence . When the burst point of the wing vortex approaches to the apex of exposed wing, the dimension of the flow with low energy is 5~8 times as large as the diameter of the body near the trailing edge of the wing.