Abstract
This study deals with the experimental and numerical studies of
the effect of free-stream turbulence on turbine blade leading edge
film cooling. The study examines several test cases with two
blowing ratios (BR=1.0 and 2.0) and three mainstream turbulence
intensities (1.0, 3.3 and 12.0 %) using two types of leading edge
models with cylindrical holes and diffuser holes [1]. The leading
edge model consists of a semi-circular part of 80mm diameter and a
flat after-body. Film effectiveness and heat transfer coefficient on
the model surface are measured by the transient method using
thermochromatic liquid crystal with video camera. In addition,
detailed investigation of the film cooling is carried out using CFD
simulations. RANS approach using Shear Stress Transport turbulence
model was employed to solve the flow field. In the case of
diffuser hole, the effect of mainstream turbulence intensity appears
significantly, and spanwise averaged film effectiveness is decreased.
