抄録
We have proposed the paint erosion method for non-contact measurement of wall shear stress distribution. The basic principle of this method is based on the assumption that erosion of paint on the wall is mainly caused by wall shear stress. Therefore, wall shear stress is estimated by detecting the decrease in paint thickness which is measured by light transmission power instantaneously using image. The relationship between wall shear stress and decreasing rate of paint thickness was clarified with steady and unsteady flow in a pipe flow. The Reynolds number was set in ranged from 885 to 14147 in steady flow to examine under laminar flow and turbulent flow condition. Frequency of unsteady flow was set 0.67, 1, and 1.13 Hz to observe influence of pulsatile flow to the erosion speed. The velocity profiles of each flow were measured by laser dopplar velocimetry. A definite correlation between wall shear stress and decreasing rate of paint thickness existed independently of the flow pattern, initial thickness, an pattern of the paint. We concluded that the paint erosion method has great potential to measure the wall shear stress without probe.
