ESTIMATION AND OPTIMIZATION OF THE FILM COOLING REQUIREMENTS IN A GAS TURBINE COMBUSTION CHAMBER

A study of film cooling requirements of a modern aero gas turbine combustion chamber over a typical aircraft flight path is undertaken. A computational procedure is used to estimate and optimize the coolant flow for a given value of the metal temperature along the whole length of the liner wall. These results are presented for a variety of mainstream and slot flow conditions. The effects of different film cooling geometries, mainstream turbulence, hot gas acceleration etc. are also investigated. It is found that for an actual liner wall, optimum values of mass flow ratio deviate significantly from unity. Increasing inlet pressure leads to increasing metal temperatures and the optimum value of mass flow ratio depends mainly upon internal radiation in the primary zone, convective components in the intermediate zone and the mainstream temperatures in the dilutio