What question did this study set out to answer?

This work aims to establish a sufficient condition for vortex breakdown in supersonic flows using enthalpy conservation.

April 1, 2026Open Access

Onset of spiral vortex breakdown in supersonic flows

THToshihiko HiejimaOsaka Metropolitan University

Key Points

This work aims to establish a sufficient condition for vortex breakdown in supersonic flows using enthalpy conservation.
Derived a sufficient condition based on conserved total enthalpy at the vortex axis
Analyzed the relationship between kinetic and internal energies downstream
Conducted numerical simulations to validate the theoretical threshold
Identified a clear relationship between squared velocity and static temperature related to vortex breakdown
Confirmed that reductions in helicity indicate the occurrence of vortex breakdown
Numerical simulations aligned with the theoretical threshold predictions

Abstract

The onset of vortex breakdown in supersonic flows remains an unsolved problem in physics. In this study, a sufficient condition for spiral vortex breakdown to occur in supersonic flows was derived from the conserved total enthalpy at the vortex axis under complete supersonic inflow conditions. The theoretical threshold was simply determined by the relationship between the magnitudes of the kinetic and internal energies (i.e. axial velocity squared and static temperature, respectively) downstream. In addition, it was found that the squared velocity and static temperature in the sufficient condition were closely related to a rapid reduction in the helicity, which indicated that vortex breakdown occurred. Numerical simulations confirmed that the theoretical threshold corresponds to the onset of spiral vortex breakdowns in supersonic flows.

Ask AI

Helpful

Bookmark

View Full Paper