Pavlov V. Structure functional and hydrodynamic properties of dolphin fins as a result of adaptation to fast swimming

The drag-reducing adaptations of dolphins were studied on the example of dorsal fin and tail flukes of dolphins. Skin structure of dolphins were studied by means of histological, image analysis, morphometry and statistical methods. Hydrodynamics properties of the fins and fin's sections were studied by means of computer fluid dynamics methods. Complex analysis of the relation between shape, skin structure, and hydrodynamics of dolphin fins was carried out. Relation between dolphin skin structure and mode of the flow in boundary layer of swimming dolphin was shown. It was found, that three-dimensional skin structure can interact with the flow like compliant wall, therefore, reducing friction drag. The idea of complex of adaptations directed to reducing drag associated with dolphin fins and including combined effect of streamlined shape and dampling properties of fin's surface is grounded.