RELAXATION MODELS FOR WAVE PHENOMENA IN LIQUID-VAPOR BUBBLE FLOW IN CHANNELS

We examine wave characteristics of a liquid-vapor mixture in order to investigate certain features of the homogeneous relaxation model. The model is described by one-dimensional averaged mass, momentum energy e quations, and a rate equation. Since the homogeneous relaxation model delivers a qualitative incompatibility of numerical and experiment res ults of large wave propagation it is extended so as to take into accou nt the heat conduction in the liquid surrounding vapor bubbles. With t his extension, the effects of spreading and damping of the waves in th e numerical solutions are similar to those observed in the experiment. Thus, a new model is created, the homogeneous relaxation-diffusion mo del which contains two physical quantities-the relaxation time and mac roscopic heat conduction coefficient Both quantities are determined ba sed on experimental data. It seems that the results obtained from the new model agree well qualitatively with the experiments.