Vortex deformation in elliptic-core jets from the perspective of linear instability analysis

Publisher Website
Google Scholar
Abstract
An attempt is made to identify the underlying mechanisms for the deformation of coherent structures that occurs in the initial state of axis switching of elliptic‐core jets. The generalized shooting method is applied to jets with elliptic‐core regions of constant flow. The analysis shows that there are three conditions on groups of eigenmodes of elliptic‐core jets which are necessary for the deformation. They are (1) proper localizations without excessive overlapping; (2) sufficiently large phase‐speed differences; and (3) comparable spatial amplification rates. The qualitative behaviors of elliptic‐core jets in relation to these three conditions are studied with respect to independent and joint variations of core eccentricity, azimuthal distribution of momentum thickness, and compressibility.

This publication has 11 references indexed in Scilit: