Meeting Abstract
There is an increasing need for doing research in drag reduction and performance enhancement techniques. Since the nature has developed processes, materials, and the functions to increase its efficiency, it has the best answers when we seek to improve or optimize a system. One of the sources for inspiring the drag-reduction methods and performance enhancement is biological aquatic systems which can be studied for their desirable properties. One of the methods in drag reduction applied by warm-bodied aquatics, such as marine mammals, scombrid fishes, and sharks is boundary layer heating. These organisms have the capacity to use heat conducted from the body surface to decrease water viscosity around their body and consequently reduce the drag. In this work, a new factor which is affecting the boundary layer of some aquatics and subsequently their skin drag reduction will be studied. The thermal effects of body color of marine organisms will be investigated in some species, such as whales, manta rays, dolphins, penguins, sharks, seals, and sailfish that have black color at the top and white color at the bottom sides of their respective bodies. Considering the marine and water characteristics of the mentioned species, a thermal analysis will be performed in this study, when these aquatic animals are in motion under the water. The surrounding fluxes including the water flux and the sun irradiation inside the water are considered in an energy balance to determine the skin temperature of both sides of the organisms’ body. Applying the Blasius solution and computational fluid dynamics methods for heated boundary layers, it will be shown, that the black color on the top and the white color on the bottom side of the bodies of these marine organisms is very efficient in terms of skin drag reduction.
