Determination of undersea vehicle hydrodynamic derivatives using the USAF Datcom

This paper investigates the use of an empirical method to estimate the hydrodynamic derivatives of streamlined undersea vehicles. These are coefficients which appear in the differential equations governing the vehicle´s motion. The USAF Datcom-a method developed to determine the analogous aerodynamic stability derivatives of aircraft-is used to perform the estimation of the non-dimensional derivatives in an incompressible medium. The derivatives are then dimensionalized using the properties of water. Because compressibility effects make up a large part of the effort in the Datcom, and are neglected in the present application, the use of this technique is relatively straightforward. Results obtained with the Datcom are presented here and compared to test results from other sources