A Quasi-3D Calculation Method for Gas Turbine Combustor Liner Wall Cooling Techniques

Abstract

To obtain more accurate estimates of wall temperature of gas turbine combustors, it is essential to include the radiation flux contribution from the flame and hot gases into each wall segment. This step calls for the knowledge of the detailed three-dimensional combustor flow field in addition to an accurate means of defining a radiation view factor. In the present investigation, a quasi-three-dimensional calculation method is adopted to predict the wall temperature of a number of production combustors. The method utilizes the flow field parameters as given by the analytical code to evaluate the radiation and convection heat loading to the wall. It makes use of empirical expressions for overall effectiveness of different cooling schemes including conventional film cooling, extended surface convective/film cooling, impingement jets and transpiration systems such as Lamilloy*, effusion, and compliant matrix cooling. The calculation technique takes into account the fuel effects on wall temperature through their impact on the detailed flow field and radiation flux. The model validation involved comparing the calculations with the measured data of several combustors that used either film cooling devices or effusion hole schemes and operated on typical aviation fuels as well as special high density fuel types. An investigation of such effects as air distribution and the spray SMD on wall temperature was also conducted in the present effort.