Abstract
In this paper, the thermally stratified boundary layer developed over a rough-wall is investigated. Two kinds of turbulent boundary layer flow with α=1/7 and α=1/4 are generated by placing roughness elements on the wall of wind tunnel, in which the floor and flow temperatures can be controlled. The changes of the turbulence characteristics of the neutral flow on the stability are shown as follows : 1) The exponent of velocity profiles increases with stability. 2) The turbulent intensity decreases with stability near wall area. 3) The effect of thermal stratification on turbulence become obvious at larger exponent of velocity profile.
