Experimental And Numerical Study On The Film Cooling Characteristics For Anisotropic Composite Plates

Experimental and numerical studies was performed to investigate the film cooling characteristics for the anisotropic composite plates.They provided some references for the thermal protection design of engine hot components.The main contents and conclusions are as follows:1)The experiment system was designed and built to investigate the wall surface temperature of the anisotropic composite plates with different weaving methods at different blowing ratios,mainstream temperature.Experimental data show that the improvement of the blowing ratio and the decrease of the mainstream temperature can reduce the temperature of the hot side wall of the composite plates and improve the total cooling efficiency.Among the three anisotropic composite plates,the 2.5D braided composite plate produces the highest total cooling efficiency while the total cooling efficiency of the 3D braided composite plate is the lowest under the same experimental conditions.2)For the anisotropic composite plate,the influence of the thermal conductivity of X,Y and Z directions on the total cooling efficiency of single-hole flat plate and multi-row flat plate was revealed by computational analysis.For the single-hole composite plate,when X/D<3,the total cooling efficiency decrease with the increase of the thermal conductivity along the X direction,while the total cooling efficiency increases with the increase of the thermal conductivity along the X direction when X/D>3.The increase of the thermal conductivity along the Y direction has little influence on the total cooling efficiency.And the total cooling efficiency increases slightly with the increase of the thermal conductivity along the Z direction.For the multi-row composite plate,on the whole,the range of total cooling efficiency decreases with the increase of the thermal conductivity along the X direction.From the local area,the total cooling efficiency increases with the improvement of the thermal conductivity along the X direction when X/D<30,and the thermal conductivity has little influence on the total cooing efficiency when 30<X/D<60,and the total cooling efficiency decreases with the increase of the thermal conductivity along the X direction when X/D > 60.The increase of the thermal conductivity along the Y or Z direction can reduce the wall temperature and improve the total cooling efficiency of the composite plate.3)For the anisotropic composite plate,the influence of the thermal conductivity of X,Y and Z directions on the impingement-film cooling efficiency of multi-row flat plate was revealed by computational analysis.The results show that,the change of the total cooling efficiency occurs with the increase of the thermal conductivity along the X direction when X/D<35 and X/D>60.The total cooling efficiency increases with the thermal conductivity along the X direction when X/D<35 while the total cooling efficiency decreases with the thermal conductivity along the X direction when X/D>60.The increase of the thermal conductivity along the Y direction has no influence on the total cooling efficiency.But the increase of the thermal conductivity along the Z direction can improve the total cooling efficiency.