基于NURBS曲面建模的三维空泡形态计算方法

空泡形态研究是超空泡航行体设计与应用的关键所在。对于充分发展的空化,将Logvinovich空泡截面独立膨胀原理与NURBS方法结合,通过航行体和空泡面的NURBS曲面建模和求交运算得到航行体的三维空泡形态,分别就轴对称型定常空泡、小攻角引起的非轴对称型定常空泡以及航行体竖直向上运动过程中的非定常空泡进行了模拟。结果表明:该方法可用于计算具有复杂外形航行体的三维空泡形态,并且可视化程度高,具有一定的工程应用参考价值。

A Calculation Method for Three-dimensional Cavity Shape Based on NURBS Surface Modeling

Cavity shape plays a significant role in the design and application of supercavitating vehicles. For the fully developed cavitation, the principle of independence of cavity sections expansion ( Logvinovich's principle) was combined with NURBS method. The three-dimensional cavity shape of vehicle was obtained by NURBS surface modeling and surface intersection operations. The steady axially symmetric cavity,non-axially symmetric cavity caused by small angles of attack and unsteady cavity in the process of vertical upward movement were simulated respectively. The result shows that this method can be efficiently used in the calculation of three-dimensional cavity shape, and it has a high degree of visibility and offers reference for engineering application.