Relation between Combustion Mode and Wall Heat Flux in a Scramjet Combustor.

Heat flux on scramjet combustor wall is measured experimentally with thermocouples in a Mach 2 supersonic combustion wind tunnel, and numerical simulations are conducted to discuss the relation between combustion mode and the heat flux profiles. The combustion in the scramjet combustor is categorized into four modes; blow-off mode, weak combustion mode, intensive combustion mode and thermal choke mode. The heat flux profile in each mode reflects the corresponding characteristic flow pattern. If there is no combustion, the wall heat flux can be estimated by Reynolds analogy. When the fuel is injected into the main flow, the heat flux profile is influenced by the behavior of the free fuel plume in the absence of the shock wave system, whereas it is influenced by separation bubbles and/or large distortion of the main flow in the presence of the shock wave system.