AN EXPERIMENTAL SIMULATION ON THE INFLUENCE OF DIFFERENT FILM COOLING HOLE SHAPES ON PARTICLE DEPOSITION ON TURBINE VANE

The deposition of particles, such as sands, dusts and volcanic ashes, on turbines could reduce the aerodynamic and cooling performance of turbines. To investigate the effect of film-cooling with different holes shapes on the deposition, an experiment at about ambient temperature is designed, in which the test models are plates but with different film-cooling hole shapes and a kind of wax is atomized as the particles. Firstly, the influence of angle of attack (AOA) on deposition is studied. The results show that, under different AOAs, the deposition rates on the pressure surface increase with the increase of AOAs. As the AOA increases from 0° to -15°, the relative increase in the deposition rate on the pressure surface of the cylindrical model is 110%, however, the deposition distribution does not change much. Therefore, the angle of attack is selected as -5° for research on the different hole shapes. After this, the effect of different hole shapes on deposition is also studied. The results show that the fan-shaped film-cooling hole could reduce the deposition rate 83% than the cylindrical film-cooling holes, and the RTSH film-cooling hole could reduce the deposition rate 79%, although most deposition forms near the film-cooling holes for all film-cooling holes shapes. The film-cooling efficiency of the plate with the fan-shaped hole could be improved by up to 16% (not relative value), and the RTSH film-cooling hole could be improved by up to 29% (not relative value), although the film-cooling efficiencies for all film-cooling holes shapes are not changed dramatically by the deposition under the experimental conditions. This study may be helpful for developing the technology of reducing the deposition and its harm on turbines.