二维气动探针非定常流测量中动态效应的数值研究

本文采用数值方法模拟了一个三孔探头周围与测压孔内的二维可压缩非定常流场，研究了动态效应对探头绕流和测孔压力的影响，以及相应的测量误差。结果显示，当流场高频振荡时（如： ２０００ Ｈｚ），其有效测量范围内的速度误差为 ２～４％，气流角误差约为 １０％之内。当流动接近失速时，该项误差迅速增大。文中还给出了高频振荡流中测压孔内外非定常与准定常流场分布之间的差异。

NUMERICAL INVESTIGATION OF THE DYNAMIC EFFECTS ON A 2D PROBE HEAD MEASURING UNSTEADY FLOW

The 2D unsteady flow fields around a 3-hole probe head and in its pressureholes have been numerically simulated in order to investigate the dynamic effects on the probe measurement errors. The results show that under high oscillating frequency, e.g. 2000 Hz, the error of velocity amplitude is around 2-3% and that of flow angle is about 10% or less when there is no separated flow around the pressure-holes, the errors become large, e.g. 4-5% or higher for velocity when small flow separation occurs; the errors increase rapidly until the probe measurement is invalidation when large flow separation appears. In the paper, the differences between the unsteady and quasi-steady velocity and pressure distributions around the probe head and in the pressure-holes are also given.