Unified gas-kinetic wave-particle methods V: Diatomic molecular flow

In this paper, the unified gas-kinetic wave-particle (UGKWP) method is further developed for diatomic gas with energy exchange between translational and rotational modes flow study in all regimes. The multiscale transport mechanism UGKWP coming from direct modelling a discretized space, where cell's Knudsen number, defined by ratio of particle mean free path over numerical cell size, determines physics simulated wave method. non-equilibrium distribution function tracked discrete analytical wave. weights distributed different regimes depend on distinguishable macroscopic variables are updated inside each control volume. becomes highly rarefied regime converges to scheme (GKS) Navier-Stokes solution continuum without particles. comparison velocity (DVM)-based (UGKS), computational cost memory requirement have been reduced several orders magnitude high speed temperature simulation, can be captured accurately transition regime. As result, hypersonic around flying vehicle, computation conducted using personal computer studies will validated various cases one dimensional shock structure three sphere, solutions compared reference DSMC results experimental measurements.