Study on Flow Coefficient of Film Cooling Hole in Combustor

The cooling hole is an important structural component of gas turbine combustion chamber. A part of air enters the combustion chamber through the cooling hole through the external passage of the combustion chamber to cool the inner wall of the combustion chamber.The cooling effect of the inner wall of the combustion chamber is related to the cooling method as well as the amount of air passing through the cooling hole.Therefore, the flow coefficient through the combustor cooling hole becomes an important basic data in the study of combustor air flow distribution and cooling method.Impact cooling and divergence cooling are two commonly used cooling methods in gas turbine combustor at present. Impact cooling holes and divergence cooling holes can be used alone, or impact-divergence cooling holes can be used to realize the cooling of the inner wall of the combustor.In order to obtain the effect of different cooling modes and cooling modes' structural parameters and aerodynamic parameters on the flow coefficient of cooling holes, numerical simulation method was used to study the flow coefficient of impact holes, divergence cooling holes and impact plus divergent double-wall cooling modes.Structural parameters focus on the spacing aperture ratio, aperture wall thickness ratio, aerodynamic parameters mainly study the inlet pressure drop ratio, primary and secondary flow direction and secondary flow inlet mode on the flow coefficient.The specific value of flow coefficient under different conditions and the variation trend with related parameters are obtained.It provides basis for combustor design and wall temperature prediction.