| Cavitation is common phenomenon, it can happen both in propeller whirling and underwater high speed vehicle moving. For underwater high speed vehicle,making the surface around by supercavitation can sharply reduce fluid drag and highly improve the speed.This way widely used in making underwater new weapon. Numerical simulation method and projectile experiment are two essential ways to do the supercavitation research. The numerical simulation method can help estimate the development situation of supercavitation , and the projectile experiment can verify the estimate result. Density and temperature are two most common characters of fluid in all its aspects in influencing supercavitation. So the effect of density and temperature of fluid on supercavitation is worth doing research.The paper through knowing the situation of the whole world’s research of supercavitation,raised the question of the effect of density and temperature of fluid on supercavitation and researched this problem with numerical simulation way and projectile method.In numerical method aspects: the paper used Renault average numerical simulation method , chose two-equation turbulence model and used the discrete method to calculate the numerical model. The boundary conditions were velocity inlet and pressure outlet. Changed the density and temperature of fluid solely to see their effects on supercavitation.In experiment aspects: designed and checked the experimental projectile, analyzed the effect of supercavitation theory、similarity theory and scale effect theory on experiment result and forecast some probable problem. Designed、checked and made the experiment equipment and controlled density and temperature solely to conduct the projectile experiment.By calculating the numerical model, we concluded that the effect of density and temperature of fluid on supercavitation was very little; we could neglect the influence in engineering application. But we need to consider the effect of density and temperature in other fluid characters, and then use these characters directly. The last experiment verified this view. |
