Bio-inspired profile improving the flow near the stern of an underwater vehicle

The utilization of underwater vehicles is becoming increasingly prevalent in a number of fields, including marine resource exploration, exploitation, and oceanographic research. The wake induced by the motion of these vehicles has the potential to significantly affect the efficiency of the vehicles. This paper draws inspiration from the sperm whale profile and investigates a bio-inspired underwater vehicle, BioUV. The bio-inspired underwater vehicle incorporates an integrated sail as an alternative to the classical sail. The flow uniformity in the stern region is assessed using the integral non-uniformity coefficient. The differences in turbulent kinetic energy in the stern region are discussed, and the effects of hull profiles on flow uniformity and turbulent kinetic energy are further investigated. Furthermore, the resistance is evaluated based on wall pressure and wall shear stress. The results reveal that, without increasing the resistance of the bio-inspired underwater vehicle, BioUV without a parallel middle body can effectively mitigate the strong adverse pressure gradient at the stern ($x/L\approx 0.85$) caused by the classical hull profile, reduce flow non-uniformity ($x/L\approx 0.88\sim 0.97$) and turbulent kinetic energy ($x/L\approx 0.90\sim 0.97$) in the stern region.