Radiation transport calculation in high enthalpy environments for two-dimensional axisymmetric geometries

Abstract

A Monte Carlo method to determine radiative source terms and boundary heat fluxes for generic, twodimensional axisymmetric geometries was developed. For the geometrical discretization, curvilinear structured grids have to be used. Thus, it is possible to use essentially the same grid as for the initial flowfield computation. The spectral behavior of gas radiation was considered as well as thermochemical nonequilibrium conditions of the medium using the NEQAIR code system. The radiation process is simulated by a large number of energycarrying bundles emitted at the appropriate locations, having the appropriate wavelength and direction of emission. These bundles are then traced on their path through the computational domain and their spectral absorption behavior is calculated. Departing from a given flowfield solution for the considered geometry, the radiation simulation method is initiated and yields the radiative source terms in an adequate form for coupling with the energy equations of the flowfield. The iteration is performed in a loosely coupled manner. A first radiation assessment for the case of a trajectory point of the ROSETTA-re-entry is presented.

The Advanced URANUS Navier-Stokes Code for the Simulation of Nonequilibrium Re-entry Flows

“…For the simulation of hyperbolic entry flows, the radiation source term is computed with the radiation transport code HERTA (High Enthalpy Radiation Transport Algorithm) 21) , which employs the program PA-RADE (Plasma Radiation Database) to determine the gas radiation spectrally resolved. 4,22) Eqs.…”