Lateral Force and Yaw Moment on a Slender Body in Forward Motion at a Yaw Angle

Abstract

This paper presents a solution method for obtaining the lateral hydrodynamic forces and moments on a submerged body translating at a yaw angle. The method is based on the infinitefluid formulation of the freesurface randomvortex method (FSRVM), which is reformulated to include the use of slenderbody theory. The resulting methodology is given the name: slenderbody FSRVM (SBFSRVM). It utilizes the viscousflow capabilities of FSRVM with a slenderbody theory assumption. The threedimensional viscousflow equations are first shown to be reducible to a sequence of twodimensional viscousfluid problems in the crossflow planes with the lowestorder effects from the forward velocity included in the crossflow plane. The theory enables one to effectively analyze the lateral forces and yaw moments on a body undergoing prescribed forward motion with the possible occurrence of crossflow separation. Applications are made to several cases of body geometry that are in steady forward motion, but at a yawed orientation. These include the case of a long “conetailâ€‌ body. Comparisons are made with existing data where possible.