TRANSIENT TEMPERATURE MEASUREMENTS OF COMBUSTOR WALLS ENCLOSING A 2-D MODEL COAXIAL INJECTOR

Abstract

Direct measurements of combustor inner wall temperatures are difficult due to harsh flow conditions. A novel approach was used to obtain the combustor wall temperature as a function of time and location in a H2-O2 model injector, enclosing acoustically forced flames. The emphasis was to obtain thermal boundary conditions for various injector operation. The new approach combined a series of experimental measurements on the outer wall with a transient heat transfer analysis applicable for low Biot number and low Fourier number conditions. Infrared thermometry technique was applied to obtain outer wall temperature distribution at three different wall thicknesses, and these measurements were combined with the transient analysis to calibrate the amount of heat transfer and the corresponding inner wall temperature. The results showed that the combustor inner wall temperature distribution evolved much differently for acoustically forced flames, suggesting a different thermal boundary condition should be used in those cases.