Comparison of inviscid and viscous vortex shedding from translating and rotating plates

TL;DR

This study compares an inviscid vortex sheet model with Navier-Stokes simulations to evaluate their accuracy in predicting vortex shedding and forces from translating and rotating plates across various flow regimes at moderate Reynolds number.

Contribution

It demonstrates the conditions under which inviscid vortex sheet models reliably predict forces and vortex structures, especially in body-dominated and flow-dominated regimes.

Findings

Inviscid model accurately predicts forces in body-dominated regimes.

Good agreement between models in flow-dominated regimes, with some limitations at low angles of attack.

The formulation supports stable, continuous vortex shedding modeling across diverse motions.

Abstract

We compare an inviscid vortex sheet model with continuous leading-edge shedding with direct Navier-Stokes simulations over a wide range of unsteady plate motions at moderate Reynolds number ($\mathrm{Re} \approx 1000$). Approximately $70$ distinct kinematic configurations are examined, spanning both body-dominated and flow-dominated regimes. In body-dominated motions, where the fluid dynamics are primarily driven by prescribed plate accelerations, the inviscid model accurately reproduces normal force histories and the qualitative structure of the induced vorticity field. In flow-dominated configurations, with quasi-periodic vortex shedding, agreement with force predictions is good but reduced at low angles of attack, reflecting the greater sensitivity of vortex shedding dynamics to physical and computational parameters. The ability of the present formulation to accommodate stable, continuous leading-edge vortex shedding enables uniform comparisons across diverse motions and clarifies the regimes in which inviscid vortex sheet models can be used reliably for force prediction and physical interpretation.