Convective and Radiative Wall Heat Transfer in Liquid Rocket Thrust Chambers

The relative weight of convective and radiative wall heat transfer in liquid rocket engine thrust chambers is estimated by means of dedicated computational fluid dynamics tools. In particular, although the convective wall heat flux is directly evaluated from the solution of the flowfield, an appropriate computational tool, based on the discrete transfer method, is developed to evaluate the radiative wall heat flux. Numerical results are compared against experimental data from the literature, concerning sub-scale thrust chambers fed with either oxygen/methane or oxygen/hydrogen. Then, the effect of varying the chamber pressure or the wall temperature is investigated via a parametric analysis. Results indicate a contribution of radiation up to 15% of the total wall heat flux for oxygen/methane and up to 11% for oxygen/hydrogen propellants.