加热对竖置平板水边界层影响的实验研究

本文用流场显示，电视录像与测量局部摩擦阻力同时进行的方法，研究了加热对竖置平板水边界层流态及摩擦阻力的影响，实验发现在流场湍度１％的水洞中，模型前部壁面的加热有效地延迟了水边界层的转捩，延长了层流区长度，相应地斑生成频率下降，处于转捩区的测力板上的平均摩擦阻力明显下降，处于层流区测力板上的摩阻略有减小，而处于湍流区侧力板上的摩阻略有增大，实验中还观察了模型头部加热引起层流分离现象。

Effects of Heat Transfer on the Boundary Layer of a Upright Flat Plate in Water

The effects of heat transfer on the boundary layer of a upright flat plate in water have been re-ported in this paper. Flow visualization, along with wall shear measurements, is used to infer the velocity field near the wall. The experiments are conducted in a water tunnel. Experimental results suggest that, in a water tunnel of 1 % turbulence level, heating the forepart of the flat plate delays the laminary-turbulence boundary lay-er transition, and the laminar riegion expands downstream. Correspondingly, the bursting frequency of the tur-bulent sports and the wall shearing stress decrease obviously in the transition region, and the wall shearing stress decreases in the laminar rigion, while the wall shearing stress increases in the turbulent region. The phenomenon of flow separation caused by heating the head of the model strongly is also observed.