Simulation of Dynamic Yaw Stability Derivatives of a Bird Using CFD

TL;DR

This paper uses CFD simulations to analyze the dynamic yaw stability derivatives of a gull bird under different harmonic motions, providing insights into bird flight stability through unsteady flow analysis.

Contribution

It introduces a CFD-based method to compute dynamic yaw stability derivatives of a bird model using harmonic motion simulations.

Findings

Good agreement between different motion simulations.

Effective use of unsteady Euler equations for flow simulation.

Harmonic Fourier analysis successfully evaluates unsteady forces.

Abstract

Simulation results on dynamic yaw stability derivatives of a gull bird by means of computational fluid dynamics are presented. Two different kinds of motions are used for determining the dynamic yaw stability derivatives CNr and CNbeta . Concerning the first one, simple lateral translation and yaw rotary motions in yaw are considered. The second one consists of combined motions. To determine dynamic yaw stability derivatives of the bird, the simulation of an unsteady flow with a bird model showing a harmonic motion is performed. The unsteady flow solution for each time step is obtained by solving unsteady Euler equations based on a finite volume approach for a smaller reduced frequency. Then, an evaluation of unsteady forces and moments for one cycle is conducted using harmonic Fourier analysis. The results on the dynamic yaw stability derivatives for both simulations of the model motion show a good agreement.