Comparison of DAC and MONACO DSMC Codes With Flat Plate Simulation

Abstract Various implementations of the direct simulation Monte Carlo (DSMC) method exist in academia, government and industry. By comparing implementations, deficiencies and merits of each can be discovered. This document reports comparisons between DSMC Analysis Code (DAC) and “MONACO”. DAC is NASA’s standard DSMC production code and MONACO is a research DSMC code developed in academia. These codes have various differences; in particular, they employ distinct computational grid definitions. On one hand, DAC employs a wall surface grid comprising unstructured triangular cells in conjunction with a volume grid comprising three-space Cartesian cells. On the other hand, MONACO employs a volume grid generally comprising unstructured cells and defines a wall surface by one of its surface boundaries. In this study, DAC and MONACO are compared by having each simulate a blunted flat plate wind tunnel test, using an identical volume mesh. Simulation expense and DSMC metrics are compared. In addition, flow results are compared with available laboratory data. Overall, this study revealed that both codes, excluding grid adaptation, performed similarly. For parallel processing, DAC was generally more efficient. As expected, code accuracy was mainly dependent on physical models employed.