低湍流度风洞中湍流度对平板边界层转捩影响的试验研究

Experimental Study of Boundary Layer Transition on a Flat Plate at Different Turbulent Level in Low Turbulence Wind Tunnel of NPU

本文报告了在西北工业大学柔壁低湍流度风洞中进行平板边界层转捩试验研究的简况及初步结果。试验湍流度为０．０２％、０．１％及０．３３％，用恒温热线风速仪测量时均速度型，求得边界层沿流向的位移厚度分布，并用示波器观察速度脉动波形变化，从而确定起始转捩点和完全转捩点位置。结果表明，转捩的规律性和国外经典结果极为吻合。

This paper describes the tests and preliminary result analysis of the research ofboundary layer transition on a flat plate in flexible wall low turbulence wind tunnel ofNorthwestern Polytcchnical University (NPU). The turbulence level used in the tests are0. 02%, 0. 1% and 0. 33%. The velocity profiles of the boundary layer were measured by useof a DISA constant temfserature hot wire anemometer, then the boundary displacement thicknessdistributiuns along the flow direction were obtained. An osillograph was used to observe the waveshape of the velocity fluctuation to obtained the position of initial transition point and the fulltransition point. Experimental results show that the locations of transition.zone coincide with theclassical results very well.