To better evaluate the performance of dual-mode scramjet combustor, the axis distribution of heat release must be predicted accurately. Current work is based on a modified 1-D model assisted by measurements acquired in a dual-mode combustor on direct-connected scramjet facility. CH~* images have been employed to study the combustion stabilization modes and further determine the start position of heat release for 1-D model. The heat release distributions of multi-ports and sing-port injections have been numerically investigated by 1-D model and validated by TDLAS measurements. The results show that heat release distributions depend on the arrangements of injections and flameholders. Close multi-ports injections bring higher combustion efficiency but further propagation of pre-combustion shock. On the contrary, sing-port injection with pure three-dimensional flowfield can obtain both high efficiency and more stable pre-combustion shock.
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