Abstract: An″X″type hot wire probe was used to measure the turbulent parameters,such as turbulent kinetic energy and turbulent stress,in boundary layers downstream of discrete film cooling holes.The probe was rotated to three orientations on its axis in order to obtain plenty information of three dimensional flow. From experimental data it is indicated that the profiles of turbulence kinetic energy in boundary layer appeared with the shape of a reversed.The blowing ratio and the number of film cooling hole rows gave significant influence on the profiles which remained in a long distance downstream. Therefore,the commonly used k-ε turbulence model could not be applied to predict this kind of boundary layer successfully without modification.

Key words: film cooling, turbulent heat transfer, boundary layer flow