Analysis of Plume Impingement Effects from Orion Crew Service Module Dual Reaction Control System Engine Firings

Abstract

Plume impingement effects on the Orion Crew Service Module (CSM) were analyzed for various dual Reaction Control System (RCS) engine firings and various configurations of the solar arrays. The study was performed using a decoupled computational fluid dynamics (CFD) and Direct Simulation Monte Carlo (DSMC) approach. This approach included a single jet plume solution for the R1E RCS engine computed with the General Aerodynamic Simulation Program (GASP) CFD code. The CFD solution was used to create an inflow surface for the DSMC solution based on the Bird continuum breakdown parameter. The DSMC solution was then used to model the dual RCS plume impingement effects on the entire CSM geometry with deployed solar arrays. However, because the continuum breakdown parameter of 0.5 could not be achieved due to geometrical constraints and because high resolution in the plume shock interaction region is desired, a focused DSMC simulation modeling only the plumes and the shock interaction region was performed. This high resolution intermediate solution was then used as the inflow to the larger DSMC solution to obtain plume impingement heating, forces, and moments on the CSM and the solar arrays for a total of 21 cases that were analyzed. The results of these simulations were used to populate the Orion CSM Aerothermal Database. Abstract. Plume impingement effects on the Orion Crew Service Module (CSM) were analyzed for various dual Reaction Control System (RCS) engine firings and various configurations of the solar arrays. The study was performed using a decoupled computational fluid dynamics (CFD) and Direct Simulation Monte Carlo (DSMC) approach. This approach included a single jet plume solution for the R1E RCS engine computed with the General Aerodynamic Simulation Program (GASP) CFD code. The CFD solution was used to create an inflow surface for the DSMC solution based on the Bird continuum breakdown parameter. The DSMC solution was then used to model the dual RCS plume impingement effects on the entire CSM geometry with deployed solar arrays. However, because the continuum breakdown parameter of 0.05 could not be achieved due to geometrical constraints and because high resolution in the plume shock interaction region is desired, a focused DSMC simulation modeling only the plumes and the shock interaction region was performed. This high resolution intermediate solution was then used as the inflow to the larger DSMC solution to obtain plume impingement heating, forces, and moments on the CSM and the solar arrays for a total of 21 cases that were analyzed. The results of these simulations were used to populate the Orion CSM Aerothermal Database.

Plume Impingement Analysis for the European Service Module Propulsion System

“…[8][9] For example, the DSMC Analysis Code (DAC) has been applied to model plumes for several different programs including plume impingement on the ISS, the Orion SM RCS engines, and the Altair lunar lander ascent engine among others. [10][11][12] These efforts have shown that DSMC is a viable method to simulate and analyze plume flows and resulting plume impingement. IEMC uses the variable hard sphere (VHS) collision model and the energy transfer treatment between molecules and walls is modeled after Borgnakke and Larsen.…”

Green Propellant Infusion Mission Program Development and Technology Maturation

“…Other DSMC implementations have been successfully used for plume flow and plume impingement studies 26,27 . For example, the DSMC Analysis Code (DAC) has been applied to model plumes for several different programs including plume impingement on the International Space Station, the Orion SM RCS engines, and the Altair lunar lander ascent engine among others 28,29,30 .…”