An aeroacoustic mechanism to explain universal behavior in hypersonic wake flow oscillations

TL;DR

This paper presents an analytical aeroacoustic model explaining the universal oscillation behavior in hypersonic wake flows behind cylinders, providing insights into flow regimes and deviations from universality.

Contribution

It introduces a new analytical model that predicts oscillation frequencies and explains the universal behavior observed in hypersonic wake flows.

Findings

Model accurately predicts experimental frequencies

Identifies flow regimes with deviations from universal behavior

Provides physical insights into aeroacoustic feedback mechanisms

Abstract

Recent experimental studies reveal that the near-wake region of a circular cylinder at hypersonic Mach numbers exhibits self-sustained flow oscillations. The oscillation frequency was found to have a universal behavior. Experimental observations suggest an aeroacoustic feedback loop to be the driving mechanism of oscillations. An analytical aeroacoustic model which predicts the experimentally observed frequencies and explains the universal behavior is presented here. The model provides physical insights and informs of flow regimes where deviations from universal behavior are to be expected.