Session: 03-02-01 Bio-Inspired and Biomedical Fluid Mechanics

Paper Number: 87633

87633 - Experimental Investigation of the Flow Over Biomimetic Fish Scale Arrays 

Aerodynamic drag plays a major role in greenhouse gas emissions, particularly in the transportation sector. Drag reduction in the form of passive surface modification is most desirable as it eliminates the need for active control methods. Surface modifications passively target the reduction of friction drag as it modifies the near-wall flow and fluid-surface interaction. Biomimetic features such as sharkskin have gained significant attention as potential passive solutions for drag reduction. Sharkskin riblets have been found to control vortices and reduce friction drag in a turbulent flow. Other biomimetic surfaces such as fish scale arrays have been shown to delay the laminar to turbulent flow transition and have the potential to reduce friction drag in the laminar and transitional flow regimes. However, the current scientific literature lacks the detailed characterization of flow over fish scale arrays. Extending our knowledge to the physical mechanisms governing the biomimetic application of fish scale arrays helps bridge the gap in passive drag reduction methods from the turbulent to the laminar and transitional flow regimes. Developing a holistic understanding of passive drag reduction mechanisms via surface modification will enable the design and manufacture of advanced low-drag micro-structured surfaces for commercial application.

The present research is focused on a detailed flow characterization and quantification of drag reduction using biomimetic fish scale arrays. Topological scale measurements from a Bluegill Sunfish study were used to design and manufacture a circular fish scale pattern from an acrylic sample. Samples were tested in a 0.5-meter-long open water channel with a 10-centimeter by 15-centimeter cross-section, at speeds up to about 0.5m/s. The experimental investigations involve particle imaging velocimetry (PIV) measurements in the vertical and horizontal planes at varying spanwise locations and heights, respectively. Detailed results will be presented and discussed.

Presenting Author: Isaac Clapp Western Univeristy