COUPLED VIBRATION-DISSOCIATION-EXCHANGE REACTIONS MODEL FOR HYPERSONIC AIR-FLOW COMPUTATIONS

A preferential coupled vibration-dissociation and exchange reactions-v ibration model resulting from an extension of the well-known Treanor a nd Marrone coupled vibration-dissociation-vibration model has been der ived to take into account the coupling between the vibrational excitat ion of the N-2 and O-2 molecules and the two Zeldovich exchange reacti ons. Analytical expressions for the exchange reactions coupling factor and for the average vibrational energy lost-or gained-by a molecule t hrough an exchange reaction have been developed, Tile influence of suc h a coupling has been shown by means of numerical simulations of hyper sonic airflows through different configurations: normal and bow shock waves, wind-tunnel nozzle, and boundary layer. Code-to-code comparison s of our model and other recent approaches and code-to-experiments com parisons have been conducted for the one-dimensional how behind a norm al shock wave. These comparisons have shown good agreement of our mode l results with the experimental data.