Fluid flow control with transformation media

TL;DR

This paper proposes a novel method inspired by transformation optics to manipulate fluid flow around objects using anisotropic porous media, potentially enabling flow cloaking and new propulsion techniques.

Contribution

It introduces a transformation-based approach to fluid flow control with anisotropic porous media, enabling cloaking and flow manipulation around 3D objects.

Findings

Flow cloaking around objects achieved

Downstream wake eliminated in simulations

Viscous drag compensated by flow manipulation

Abstract

We introduce a new concept for the manipulation of fluid flow around three-dimensional bodies. Inspired by transformation optics, the concept is based on a mathematical idea of coordinate transformations and physically implemented with anisotropic porous media permeable to the flow of fluids. In two situations - for an impermeable object placed either in a free-flowing fluid or in a fluid-filled porous medium - we show that the object can be coated with an inhomogeneous, anisotropic permeable medium, such as to preserve the flow that would have existed in the absence of the object. The proposed fluid flow cloak eliminates downstream wake and compensates viscous drag, hinting us at the possibility of novel propulsion techniques.