For numerical simulations of reacting, viscous nozzle flows in advance
d rocket nozzles, a numerical method has been developed. The code is b
ased on the well established DLR Euler/thin layer Navier-Stokes code N
SHYP that was originally written for hypersonic re entry how simulatio
ns. The code solves the three-dimensional, time-dependent Euler and th
in-layer Navier-Stokes equations in conservation law form, Hydrogen an
d oxygen are considered as fuel and oxidizer, respectively. The passiv
e scaler approach accounts for the multicomponent diffusion effects. T
urbulent transport is described with an algebraic eddy-viscosity, and
a k-epsilon two-equations model. Calculations of conventional bell noz
zles were performed, Results of Vulcan Mark 1 nozzle flow simulations
are shown and compared in detail with another well-established numeric
al approach, based an the method of characteristics. A modified Vulcan
engine is proposed, where the gas generator exhaust gases are injecte
d into the main nozzle. Results of an engine analysis are presented. B
ased on this engine analysis, numerical flowfield calculations of the
modified nozzle were performed and are presented.