Enhancements of the Flow Solver TAU for Internal Flows at Supercritical Pressures
Proceedings of the 3rd International Conference of Fluid Flow, Heat and Mass Transfer (FFHMT'16)
This present paper discusses numerical investigations to verify the real fluid solver version of the DLR Navier-Stokes code TAU. Longterm goal is the simulation of real fluid cooling channel flows for liquid rocket engines (LREs). To verify the infrastructure of the code, a numerical micro-tube flow test case based on methane is selected. Due to severe problems in solving the stiff thermodynamics for real propellants and that security restrictions for experiments impede the use of hydrogen as
... se of hydrogen as propellant, most of the validation experiments are conducted with nitrogen. The use of nitrogen under supercritical pressure is an accepted strategy towards high pressure liquid rocket engine flows. To enable the computations, a modified Benedict-Webb-Rubin (MBWR) real fluid thermodynamic treatment and several boundary conditions have been implemented accounting for high pressure internal flow with heat transfer. Fluid properties have been chosen to supercritical pressure and subcritical temperatures at the inflow and supercritical pressure and temperature at the outflow due to heating. This ensures fluid conditions in the pseudo-critical region. In conclusion it can be shown that the TAU code is suitable to deal with real fluid convective heat transfer, although there are still a few stability concerns regarding realistic propellants like hydrogen and methane. By changing the infrastructure of the MBWR lookup table it is, eventually, possible to get a good trade-off between stability and performance.