Experimental analysis of Surface-modified Structured Torpedo model

Abstract

This work is motivated by the significant efforts aimed at improving the aerodynamic performance of navigating objects using bio-inspired surface modification. Inspired by the tooth-like denticles over sharkskin, this work describes the experimental study on a surface-modified structured torpedo prototype. This work studies the effects of uniform inflow on the drag properties and wake structure of flow over the torpedo prototype. The torpedo is fabricated in-house with a 3D printer. The experiments are performed in low turbulence, open circuit subsonic wind tunnel with Hotwire anemometer for data acquisition. The analysis is done for inflow velocity varying between 2-10 m/s with and without riblet surfaces. The maximum Reynolds number for the study is 4.2×10⁵. The velocity and fluctuation analysis shows the variation in wake width and wake velocity for different surfaces. The study reveals that riblets structure enhances the momentum flux, thus enable the surface to reduce drag for adverse pressure gradients. The result showed that riblet effectively reduces drag coefficient by 10.5% at 4m/s. The results show the perspective to improve the current research status by using riblet surface for marine application.