Hypersonic Vehicle Analyses: The Needs and Challenges of Multidisciplinary Simulations

We examined two different chemistry models for the purpose of understanding how chemistry modeling can affect the trajectories we can fly. The first model is the Legacy two temperature model by Park, commonly used in hypersonic flow codes worldwide. The second model is the modified Marrone Trainer model (MMT), a newer model based on a decade of Computational Chemistry research by various groups globally.

Our goal was to analyze how these two models differ in predicting heat transfer for a spear cone flying at five kilometers per second at altitudes ranging from sea level to 80 kilometers. Our comparisons showed that the Park and MMT models agree at very low and very high altitudes, but there are discrepancies in heat transfer predictions at intermediate altitudes. Sometimes MMT predicts lower heat transfer, while other times it predicts higher heat transfer.

These findings have raised questions about the impact of these discrepancies on trajectory design and optimization.