跨音速翼型风洞缝壁开度选择初探

对跨音速风洞洞壁干扰问题的研究由来已久。经典的洞壁干扰理论是以考虑压缩性影响的线化亚音速理论为基础的。将此线性理论用于跨音速风洞,存在着根本缺陷。另一方面,由于人们缺乏对透气壁流体流动及粘性损失特性的足够了解,过去的干扰修正理论都只能基于半经验的均匀线化边界条件。随着计算流体力学的迅速发展,出现直接求解跨音速非线性方程确定洞壁干扰的方法,但这类方法,由于使用均匀线化边界条件,其适用性仍十分有限。

A TENTATIVE OPTION FOR VENTILATION RATIO OF SLOTTED WALL IN TWO-DIMENTIONAL TRANSONIC WIND TUNNEL

The present paper gives the results of the slotted wall interference study in two-dimentional transonic wind tunnel.First, a model was tested in the slotted wall test section with two pressure rails. A NACA0012 airfoil was used for the model, Mach numbers were 0.6, 0.75 and 0.9, the angles cf attack were 0°to 3°, the ventilation ratios of slotted wall were 2% and 5%.Second, a simple computing method to assessing wall interference was developed using the transonic small disturbance pressure equationComparing experimental and computed results, we carefully analyze the influence on the wall interference exerted by the variation of ventilation ratio, Mach number and angle of attack. The result shows that the adoption of uneven ventilated wall is benifitial to decrease or even remove the wall interference.