Interaction of aerospike nozzle flows with external flows

The function of launch vehicles is to carry satellites into a stable earth orbit. Efficient and safe transport is particularly important from both an economic and an ecological point of view. The typically installed thrusters have a bell shape, which is designed for a certain pressure ratio between the nozzle and ambient. However, as the flight trajectory progresses, this ratio changes, resulting in non-ideal operating points where over- or underexpansion of the propulsive jet leads to reduced thrust efficiency, while potential flow separations cause increased mechanical loads.

In the so-called aerospike nozzle, the propulsion jet does not expand against an external bell contour, but against the ambient pressure, which theoretically enables it to adjust the propulsion jet in the direction of the optimum operating point, at least in the overexpanding case. It is able to do this without moving elements and forced flow separation.

The aim of this research project is to experimentally investigate the flow of a model aerospike nozzle in combination with external flow. For this purpose, external flows in the Mach number range from 0.3 to 3.0 are to be realized in the Trisonic Wind Tunnel Munich (TWM). With the aid of Schlieren imaging, PIV and oil coating tests, gas dynamic phenomena occurring under different operating conditions of the nozzle are to be identified and made visible. In the further course of the project, the flow behavior of an aerospike nozzle with a truncated nozzle core will be investigated as well. This is an extremely relevant adaptation, since the full length of the core contributes little to thrust, but significantly to mass and manufacturability. In addition, modification of the nozzle exit in the form of nozzle clusters is part of the project. The modified model will be used to investigate the flow while performing a thrust vector control strategy.



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Person in charge:

  • Paul Wißmann M. Sc.



  • German Research Foundation (DFG)



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