Abstract
This paper describes the structures of turbulent boundary layers on the wind tunnel rough surfaces which are regularly arranged with simple roughness elements. The followings are the outlines of our experiments; The identities of turbulent Reynolds Number (U_z/K_z) and the ratio of representative length and roughness parameter (L/z_0) are confirmed on the geometrically similar rough surfaces. The turbulent structures such as mixing length, energy dissipation and so on become similar, and the formula of reduced scale free stream U_<∞M>/U_<∞N>=(ε_M/ε_N)^<1/3>(L_M/L_N)^<1/3> is formed at the both cases of U_∞=constant and U_∞∝L^<1/3> on the reduced scale rough surfaces. The profiles of mean velocity and turbulent intensity in our tests are similar to those of field observations in surface layer at Tokyo. From the results of this experiments, it can be said that the small tunnels in this use are valid for the studies of wind effects on buildings, if the reduced scale models can be constructed corresponding to the growth of surface boundary layers on the tunnel surface.
