In recent years there has been a growing interest in ceramic materials for high-temperature gas turbine chambers. Owing to different material properties, these gas turbine chambers have thicker walls than the metallic ones and, thus, a different geometry of the film-cooling slots, which affects the flow field. In this work the mean and fluctuating velocities and fluid temperatures have been studied numerically for two different lip-to-slot ratios. When the lip is thick, the flow becomes unsteady and a vortex street appears behind the lip; hence, unsteady computations have been carried out. The calculated results are compared with single hot-wire measurements made recently by Boman [I].