Modelling an acoustically perturbed rocket engine combustion chamber with cryogenic propellant injection

An experimental combustor, dubbed BKH, has been developed at DLR Lampoldshausen to investigate combustion instability phenomena. The combustor operates with cryogenic liquid oxygen and hydrogen propellants at supercritical pressure conditions analogous to real rocket engines. The BKH combustor has been modelled using a specially developed version of the DLR TAU code with real gas capabilities for supercritical injection. The TAU code CFD results are compared with optical data recorded during BKH experiments. The numerical flame and liquid oxygen distributions match experimental observations. The acoustic field inside the BKH combustor has also been calculated separately with an acoustic solver that uses a realistic acoustic property distribution from the CFD calculations. The resonant modes are successfully predicted using the acoustic solver.