Numerical Simulation For Counterflow Convection-film Cooling Of A Gas Turbine Combustor Liner With Ribbed Wall

Ribbed flame tube counter-flow film cooling structure has a unique advantage in the aspect of gas turbine flame tube cooling.The surface of the ribbed flame has increased the roughness of the heat transfer wall in the cooling channel and the heat exchange area of the heat exchanger wall and the cooling air flow.The high-speed flow of cooling air film isolates the high temperature gas from the wall surface of the flame,thus greatly improving the cooling efficiency.In this paper,aiming at the problem of the cooling of the reflux gas film of the gas turbine flame cylinder,a fluid-solid coupled mathematical model for cooling heat transfer in flame tube is established.Among them,considering the propagation of turbulent shear stress,in the near wall,using the robustness of k-? model to capture the flow of viscous underlayer.The k-? model is used to avoid the disadvantage k-? for the over-sensitivity of inlet turbulence parameters in mainstream area.The SST k-? model used in this paper is a turbulent model which combines k-? model and k-? model with a mixture function to better fit the problem.In this paper,first of all,based on the study of the combustion chamber wall impactreverse convection-air film cooling characteristics based on published experimental data,the cooling structure of the corresponding combustion chamber wall reflux gas film is established.Using the method of fluid-solid coupling for numerical simulation,the coincidence of calculation results and experimental results is verified.Then according to the rib with the 300 mw gas turbine flame tube wall of the actual size,setting up corresponding geometric model,the calculation method of using validated the model for numerical simulation of the numerical analysis results clearly demonstrated the calculation domain of fluid flow field,temperature field and flame tube wall temperature field distribution of the rib.Finally,on the basis of the numerical analysis of gas turbine cooling ribbed wall counter-flow film cooling structure,the effect of blowing ratio on the cooling effect of the flame tube counter-flow film cooling structure with ribbed wall is studied in detail.The numerical analysis shows that the high temperature zone and the thermal stress concentration area of the flame tube are obtained.The results show that the change of the blowing ratio has an important influence on the cooling structure of the counter-flow film in the ribbed flame tube.