Vibrational nonequilibrium distribution of diatomic molecules

An attempt is made to develop an analytical model to modify the Hammerling's hypothesis in dealing with the vibration modes for diatomic under nonequilibrium states. The characteristics of distribution functions for vibration modes of diatomic molecules molecules undergoing a nonequilibrium relaxation process are studied and a new approximate form of distribution functions is proposed. The calculations of test cases show that the majority of the characteristics of the vibration modes can be represented by the deduced approximate function. The utilization of the formulation on computations of the rate of the N₂ dissociation undergoing a nonequilibrium relaxation process has demonstrated to be successful, and the study also partly verify the theory behind Park's two-temperature model.