Mixing enhancement by shock impingement in a generic scramjet combustion chamber

The present paper focuses on the mixing improvement in a generic supersonic combustion chamber for a fixed combustion chamber height with wall injection. On the one hand, internal shocks are employed to increase mixing and penetration, on the other hand injector design and spacing are investigated to achieve good penetration and mixing. With sonic hole injectors, a reduction of the injector spacing improves the mixing efficiency almost proportionally due to the reduced required massflow per injector. At very high aspect ratios, the relative penetration is reduced and the air in the upper part of the duct does not mix properly with the fuel. Penetration improvement due to the internal shock system, and tilted, supersonic inline injectors are presented to improve the mixing efficiency