Starting Flow Past an Airfoil and its Acquired Lift in a Superfluid

Phys Rev Lett. 2019 Oct 11;123(15):154502. doi: 10.1103/PhysRevLett.123.154502.

Abstract

We investigate superfluid flow around an airfoil accelerated to a finite velocity from rest. Using simulations of the Gross-Pitaevskii equation we find striking similarities to viscous flows: from production of starting vortices to convergence of airfoil circulation onto a quantized version of the Kutta-Joukowski circulation. We predict the number of quantized vortices nucleated by a given foil via a phenomenological argument. We further find stall-like behavior governed by airfoil speed, not angle of attack, as in classical flows. Finally we analyze the lift and drag acting on the airfoil.