A theoretical study on the overlap region in a flat plate turbulent boundary layer

作者：Nishioka Michio^*

来源：Fluid Dynamics Research, 2010, 42(4): 045502.

DOI：10.1088/0169-5983/42/4/045502

This paper studies the wall-law defect-law overlap region in a zero pressure gradient turbulent boundary layer. By taking account of the non-parallel flow effect, a system of differential equations is derived, which describes the velocity profile for the overlap layer and the velocity and length scales for the outer layer. Two kinds of solutions are obtained for the velocity profile in combination with corresponding solutions for the outer layer scales. One is of log-law type and the other is of power-law type. These are possible solutions that represent the necessary condition for the existence of the overlap layer. In the light of the present solutions, recent experimental data for a zero pressure gradient turbulent boundary layer are examined. It is found that the observed velocity data follow the log-law solution for momentum thickness Reynolds numbers R(theta) above 20000.

• 出版日期2010-8