Numerical Investigation of Hydrogen Strut Injections into Supersonic Airflows

The in uence of different injector geometries on the mixing behavior of planar supersonic jets is investigated. Hydrogen is injected in the  owdirection throughthebluntendofa strut.Different lip thicknesses at the injector end induce different extents of recirculation zones. Additionally, changes are caused within the shock-wave/expansion fan pattern at the injector exit that have an important in uence on loss in total pressure. The accuracy of the used numerical scheme is demonstrated for one injector geometry by comparison with experimental data. Based on this conŽ guration,modiŽ cations in lip thickness and injection Mach number are investigated numerically and are assessed using several calculated performance parameters. Results show that the chosen lip thickness has a much stronger in uence on loss in total pressure thanmoderatemodiŽ cations in injector length and height. For the very thin hydrogen jets that were investigated, the mixing efŽ ciency is nearly independent on injector lip thickness.

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