Abstract:
Using the theoretical proof and numerical computation methods, this paper investigates the impact of different thermophysics models on the characteristics of cavitation bubble at the end, and analyzes their graphics, data and its local detail.The results show that with the increase of the polytropic index γ, the maximum combined external force and kinetic energy are gradually reduced, the maximum temperature inside the cavitation bubble is gradually increased, and the maximum pressure is gradually reduced.At the collapse closed point of cavitation bubble, the combined work force, kinetic energy and the radius reach the minimum value, at the same time, the temperature and pressure come to the maximal value, and all five of them have the simultaneity characteristics.When the cavitation bubble is compressed to the initial radius point R=R0, this point is the corresponding stagnation radius of combined external force and kinetic energy, at the same time, this point is also the demarcation point of isothermal process and the adiabatic process.This cavitation process is called the thermodynamics isothermal process including the begin of cavi〖JP+1〗tation bubble expansion to the maximum radius and the compressed to the original radius point R=R0.After that, from the beginning of cavitation bubble compressed to the initial radius until to the first time collapse closed point of cavitation bubble, that is the cavitation bubble radius reach the minimum radius R = Rmin, this process is called dynamics adiabatic process.At the same cavitation process of air cavitation bubble, the different thermophysics models of cavitation bubble are adopted at different stages.During the stage of thermodynamics isothermal process, the polytropic ratio of γ is taken equal to 1.0.During the dynamics adiabatic process, the polytropic ratio of γ is taken equal to 1.3～1.4 which are more reasonable.
