Investigation On Cooling Characteristics Of Combustor Flame Tube Wall

Gas turbine is a new generation of powertrain after steam turbine and internal combustion engine,which is widely used in the national economy and defense industries. With the continuousimprovement of the performance of gas turbine, pressure ratio of the compressor and temperature ofthe combustion chamber constantly increase, on one hand, the temperature of cooling air increaseswith it, then the cooling potential becomes lower and lower, on the other hand, the percent that the airused for cooling becomes small and small, which makes the temperature of the combustion chamberfar higher than the temperature that the material can resistant. Therefore, in order to ensure the safeand stable operation of the combustion chamber, it is necessary to develop advanced cooling methods.Both numerical and experimental methods were used to analysis the cooling efficiency and flowresistance characteristics of the impingement+convection+film cooling configuration. The coolingmedium is air. In order to study the effects of geometric parameters and blowing ratio on the coolingefficiency of the cooling configuration, many sets of numerical simulation and test models weredesigned. And then the computational results were compared with the testing results. Through theabove research, we get the following conclusions:At the same wall position in the film board, cooling efficiency increases with the increase of theblowing ratio. When the blowing ratio increases to a certain value, the increase of cooling efficiencyis small. The pressure loss coefficient also increases with the increase of blow ratio.Overall, the angle between film hole and the flow direction of mainstream hardly influences thecooling efficiency, however, the distance of each impingement hole in flow direction has influence onit.Under normal circumstances, the cooling efficiency of the impingement+reverse convection+film cooling structure is higher than the cooling efficiency of impingement+identical flowconvection+film cooling structure.The changing rule of the cooling efficiency acquired from the numerical simulation wasconsistent with the result of the experiment.