Is there a case for emulating a fish or other sea borne creatures for propulsion of underwater vehicles?

Fish and other sea borne creatures have invoked interest in the minds of many professionals to study how they propel themselves in water and whether similar principles can be applied to the design of underwater vehicles. Adopting these principles for propulsion had been a challenge some decades ago, but with the current technological progress in robotics, design analysis, advanced computing, precision manufacturing, 3D printing, sensors, actuation, image processing etc have rekindled an interest in this field, especially in the Indian context. Moreover, with the thrust on development of unmanned autonomous systems, especially for the naval warfare, there is a case for looking at an efficient way to propel such vehicles that can stay underwater for a longer duration, move and navigate faster than those traditionally shaped and propelled by screw propellers or pump jets. This paper looks at some of the basics of fish locomotion; technology trends; examples of the current developments; benefits of emerging technologies, investigate performance of some basic shapes of caudal fin of fish with the help of modern analytical tools such as Computational Fluid Dynamics and the way ahead