潜艇类组合体之位势流计算法

对绕任意形状三维物体位势流的计算,近二十年来,人们已经发展了一些成功的方法,其多数属于面元法。由于我们感兴趣的物体,其外形的极端复杂性,所以用现有这些方法来解决其绕流问题,要求有相当大内存的计算机,且计算时间过长。本文针对潜艇一类具有近似旋成体的外形特点,当选定旋成体作为参考物体后,则整个计算过程可分解为: (1)求解参考体的位势绕流问题。由于其轴对称性,所以可应用线元法求解。 (2)考虑真实物体与参考物体的差别,可应用FFT算法求解。 (3)计算指挥台与真实物体的相互影响时,用参考物体代替真实物体,同样可应用FFT算法求解。 (4)计算尾舵的绕流问题时,类似于指挥台一样处理。 这样,计算机的存储量和计算时间都将大大降低。 六十年代以来,随着高速数字电子计算机的飞跃进步,对于绕任意形状三维物体的位流计算,已发展了不少成熟的方法。但用它们来计算飞机、潜艇这类组合体的绕流问题,都要求有相当大内存的计算机,且计算工作量也过大。本文针对潜艇一类近似旋成体的组合体问题,根据其外形特点,利用“部件干扰”的思想,在不降低精度的情况下,通过采用Fourier分析方法,给出了一种工作量较少,同时降低了对计算机容量要求的简单实用的计算方法。

A COMPUTATIONAL METHOD FOR POTENTIAL FLOW AROUND SUBMARINETYPE ASSEMBLY

Computational methods for potential flow around arbitrary 3-D bodies have been proposed successively in the last 20 years. Most of them are panel methods[1-6]. Because of the great complexity of configuration of the bodies that we are interested in, memory-size and calculating time of the computer needed for using those methods are very large. In the present study, the configuration of submarines, which are roughly axisymmetrical, is considered. Choosing an axisymmetrical body as a reference body, the whole calculating process can been resolved in the following ways:1. Solve the potential flow around the reference body. Because of the axisymmetricity, line panels may be used.2. Considering the departure of the real body from the reference one, F. F. T. can be used here.3. In calculating flow around the fairwater with the reference body instead of the real body, F. F. T. can be used again.4. Calculate flow near the stern in the similar way.Calculating time and storage of the computer is thus greatly reduced.