Hot-Gas-Side Heat Transfer Characteristics of a Ribbed Combustor

Abstract

For expander cycle liquid rocket engines, the enhancement of the heat transfer between combustion gas and regenerative coolant is one of the key issues. The adoption of a ribbed combustor is one possible method of enhancing heat transfer. Hot firing tests of sub-scale combustors with hot gas side wall ribs were conducted to evaluate enhancement of hot gas side wall heat extraction. Based on the firing test results, the influence of combustion pressure and mixture ratio on heat transfer enhancement was evaluated as the basic heat transfer characteristics with ribs and the scale effect was also examined. Nomenclature Pc = chamber pressure MR = mixture ratio ηC* = efficiency of characteristic exhaust velocity φ = rib efficiency