Extreme Aerodynamics: A Data-Driven Perspective

TL;DR

This paper discusses the challenges and opportunities of studying extreme aerodynamics in unsteady atmospheric conditions for small air vehicles, emphasizing data-driven methods for complex, nonlinear flow physics.

Contribution

It introduces the concept of extreme aerodynamics with gust ratios over 1 and highlights data-driven approaches as key to understanding these complex flow phenomena.

Findings

Extreme aerodynamics involve strong nonlinearity and transient dynamics.

Data-driven methods can analyze rich flow physics in extreme conditions.

Opportunities exist for applying these techniques to broader fluid dynamics problems.

Abstract

While experiencing atmospheric turbulence on a commercial flight can be uncomfortable, it rarely compromises the stability of the aircraft. The situation is quite different for small air vehicles that operate in urban canyons, around mountainous terrains, and in the wakes of marine vessels, where they could encounter highly unsteady atmospheric conditions with relatively strong gusts. The spatiotemporal scales of such disturbances can be larger than the characteristic aerodynamic scales of the small vehicles, making the relative effect of disturbance significantly stronger than what a large commercial aircraft would experience. The gust ratio can exceed 1 in these extreme flight environments, making stable flight difficult, if not currently impossible. We refer to the study of aerodynamics for gust ratios over 1, extreme aerodynamics, and identify major challenges that require breakthroughs, particularly with data-driven approaches. Extreme aerodynamics present unique opportunities for innovative analysis techniques to study rich flow physics problems with strong nonlinearity, transient dynamics, and low-dimensional modeling over a large parameter space. Some of the approaches discussed herein should apply to a wider range of fluid dynamics problems with similar challenges.