Deployable vortex generators for low Reynolds numbers applications powered by cephalopods inspired artificial muscles

iScience. 2023 Nov 2;26(12):108369. doi: 10.1016/j.isci.2023.108369. eCollection 2023 Dec 15.

Abstract

This paper proposes deployable vortex generators (VGs) powered by twisted spiral artificial muscles (TSAMs). TSAMs take inspiration from cephalopods' papillae and can protrude out of plane upon electro-thermal actuation with an output strain of 2000% and an input voltage of 0.2 V/cm. Unlike passive VGs, designed for specific flow conditions, this technology can adjust to changes in flow conditions by overcoming the limitations of existing active flow control devices in terms of portability and power requirements. Our technology can deploy different VGs configurations on demand, and match a desired target configuration, optimized for a specific flow condition. Experiments were conducted in a wind tunnel using a NASA Langley Research Center LS (1)-0417 GA(W)-1 airfoil. Stall delays and lift increase have been demonstrated for different flow conditions, with Reynolds numbers between 100,000 and 140,000. These findings are promising for enhancing efficiency in small unmanned aerial vehicles operating at low Reynolds numbers.

Keywords: Biologically inspired engineering; Devices; aerodynamics.