Validation of the DLR TAU Code for Scale-Resolving Combustion Simulations

Kurzfassung

The accurate numerical simulation of combustion processes in rocket thrust chambers is a key element in the design of future space transportation vehicles. Besides the need for robust and fast RANS methods for evaluating different design approaches, scale-resolving simulation techniques like Large- and Detached-Eddy simulations allow to gain insight into complex dynamic processes in the combustion chamber. One example for this is the development of combustion instability which is currently not fully understood. This work will present the extension of the DLR TAU code for chemically reacting scale-resolving flow simulations. This work presents detached-eddy simulation results for the DLR H-3 GH2/Air flame using a progress-variable flamelet model. The DLR-H3 flame is a low-speed jet flame under ambient conditions that has been studied experimentally and numerically by many groups. Due to its simple and accessible experimental setup, various measurements of flow velocities and species mass fractions are available. We will present comparison to the experimental results as well as a detailed analysis of the grid resolution. Also, different numerical approaches will be presented and compared. A second study will focus on the the capabilities of the TAU code to accurately model the unsteady mixing process of real-gas O2 with gaseous hydrogen under high pressure conditions. For this part of the work, the real-gas extensions of TAU will be applied to the numerical case of Ruiz et al. This test case models the mixing of cryogenic O2 and GH2 behind a bluff body in a 2D geometry. Although this is a purely numerical test case, a comparison with the results of TAU will give valuable insights into the capabilities of TAU compared to other solvers.