J. Choi, R. Penmetsa, R. Grandhi
Feb 1, 2005
Citations
1
Influential Citations
36
Citations
Journal
Structural and Multidisciplinary Optimization
Abstract
The torpedo is a vital component of the naval arsenal, and efforts are continually directed toward improving the technology to make the torpedo more lethal and more stealthy. Recently, a new direction of research is considering the high-speed torpedo, which is capable of reaching up to 200 mph underwater. When a torpedo travels at this speed, the flow around the body separates and a cavity is formed. This cavity generation due to high speeds is called supercavitation. And the drag force acting on this supercavitating torpedo dictates the thrust requirements for the propulsion system, to maintain a required cavity at the operating speed. Therefore, any reduction in the drag force, obtained by modifying the shape of the cavitator or the nose of the torpedo, would result in lower propulsion requirements. In this work, shape optimization techniques were employed to determine the optimum (minimum-drag) shape of the cavitator given certain operating conditions. Shape optimization was also used to determine the shape of the cavity for any given cavitator, using potential flow theory. Analytical sensitivities were derived for various parameters in order to implement a gradient-based optimization algorithm. The developed methodology is an optimization process where the cavity and cavitator shapes are determined simultaneously. The cavitator shape that induces minimum drag and the corresponding cavity shape can be used to model a supercavitating torpedo that fits in the generated cavity and satisfies the required performance characteristics.