三维空泡回射流的理论研究

空泡回射流以某个方向冲击空泡壁面是导致空泡发生不同脱落方式的重要原因,但是空泡回射流的方向目前认为是一个不确定量,需要人为指定.该文针对无界重力流场中的三维空泡,基于势流假设和积分方程推导了一个计算回射流角度和回射流截面面积的三角函数代数方程组,并且在小角度条件下给出了回射流角度和截面面积的理论解析式.研究表明,空泡回射流角度与空化器的攻角、阻力和空泡浮力有关.

A Theoretical Study for Three-dimensional Cavity Re-entrant Jets

An important reason for various patterns of cavity shedding is the cavity re-entrant jet im-pinging against the cavity wall in a certain direction. However, the direction of the cavity re-entrant jet is currently considered as an uncertainty, which needs to be determined artificially. This paper fo-cused on the three-dimensional cavity in an infinite flow field with gravity. A system of algebraic e-quations with trigonometric functions, which can calculate the angle and the sectional area of the re-entrant jet, was deducted based on the potential flow theory and integral equations. A theoretical ana-lytic formula for the angle and the sectional area of the re-entrant jet on the condition of small an-gles was obtained. The study shows that the angle of a cavity re-entrant jet relates to the attack an-gle and resistance of the cavitator and the cavity buoyancy.