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Proposing Institution

Institut für Aerodynamik und Strömungstechnik, Raumfahrzeuge
Project Manager

Prof. Dr. Klaus Hannemann
Bunsenstr. 10
37037 Göttingen
The accurate numerical simulation of combustion processes in rocket thrust chambers is a key element in thedesign of future space transportation vehicles. Besides the need for robust and fast RANS methods forevaluating different design approaches, scale-resolving simulation techniques like large- anddetached-eddy simulations allow to gain insight into complex dynamic processes in the combustion chamber. One particularly important example for such a multi physics process is the coupling of a chemically reacting flow with acoustic excitations in rocket thrust chambers. This coupling can give rise to very large acoustic amplitudes that possibly damage the engine or can lead to complete failure. Due to the harsh and difficult experimental conditions in such combustion devices, numerical simulations play a key role in understanding these phenomena.In this work, the DLR TAU code will be used to simulate the response of a chemically reacting flow to acoustic excitations in the subscale combustion chamber BKH (Brennkammer H) from DLR Lampoldshausen. Our work focuses on a BKH operating point that hasn't been studied numerically before. In contrast to previous studies operating with ambient temperature hydrogen and supercritical oxygen injection, we will use transcritical cold hydrogen in our simulations to reproduce the results from the experimental group.The DLR TAU code has been extended recently for the simulation of chemically reacting flows with real-gas thermodynamics. We will use a flamelet based combustion model suitable for real-gas combustion applications along with a detached-eddy turbulence model to accurately capture the flow inside the combustion chamber. The acoustic excitation inside the chamber will be modeled using a siren outflow boundary condition representing the true experimental setup.From our simulations we expect to find a shortening and flattening of the flames under transverse acoustic excitations. The numerical results will then be compared to shadowgraph and OH emission images that have been obtained during the experimental campaign. In addition to that, detailed pressure measurements at different locations inside the combustion chamber allow to reconstruct the acoustic mode shapes.

Impressum, Conny Wendler