Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.582295
Title: Numerical identification of fast structural growth in stratified turbulence
Author: Parmar, Amar S.
Awarding Body: University of Warwick
Current Institution: University of Warwick
Date of Award: 2012
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Abstract:
We investigate a type of instability observed in the presence of two counter rotating vortex columns in a highly stratfied fluid, Fr < 1. This instability causes the vortex columns to be bent and stretched out in the horizontal direction eventually leading to discrete horizontal layers of vorticity. The instability is known as the zigzag instability and causes exponential growth in total enstrophy which stops once viscous dissipation becomes im- portant. We find that two counter rotating vortex columns with localised perturbations applied parallel to the direction of propagation and offset from one another between the two columns is an initial profile that is highly unstable to the zigzag instability leading to exponential enstrophy growth faster than any prior numerical simulations have shown however is consistent in timing with a previous experimental result. We show that the zigzag instability that develops on these vortex columns provides a mechanism for energy (kinetic and potential) to cascade from large scales to small scales.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.582295  DOI: Not available
Keywords: QA Mathematics ; TA Engineering (General). Civil engineering (General)
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