# Flying in a superfluid: starting flow past an airfoil

## TL;DR

This paper explores superfluid flow around an airfoil, revealing phenomena similar to classical viscous flows, including vortex production and circulation, with unique quantum effects like vortex nucleation and quantized circulation.

## Contribution

It demonstrates that superfluid flow exhibits classical-like behaviors and introduces a phenomenological model to predict vortex nucleation, highlighting quantum effects in aerodynamic contexts.

## Key findings

- Superfluid flow produces starting vortices similar to viscous flows.
- Circulation converges onto a quantized value predicted by the model.
- Stall behavior depends on airfoil speed, not angle of attack.

## 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.