Transient growth in a flat plate boundary layer under a stream with uniform shear

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Bibliographische Detailangaben
Hauptverfasser:	Gopalakrishnan, Shyam Sunder, Mandal, Alakesh Chandra
Format:	Preprint
Veröffentlicht:	2021
Schlagworte:	Fluid Dynamics
Online-Zugang:	Acceder al recurso
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author	Gopalakrishnan, Shyam Sunder Mandal, Alakesh Chandra
author_facet	Gopalakrishnan, Shyam Sunder Mandal, Alakesh Chandra
contents	One of the simplest problems involving external vorticity in boundary layer flows is the flow over a semi-infinite plate under a stream of uniform shear. We study the transient growth phenomenon in this flow to investigate the role of freestream shear on energy amplification, and analyse the differences with the Blasius flow. The initial optimal disturbance which triggers the maximum growth is found to be streamwise vortices, as in other shear flows. Compared to the Blasius boundary layer, higher optimum energy and larger spanwise wavelength of streamwise vortices have been observed. We provide scaling laws for the maximum optimal amplification, which is found to increase exponentially with the freestream shear gradient.
format	Preprint
id	arxiv_https___arxiv_org_abs_2107_08696
institution	arXiv
publishDate	2021
record_format	arxiv
spellingShingle	Transient growth in a flat plate boundary layer under a stream with uniform shear Gopalakrishnan, Shyam Sunder Mandal, Alakesh Chandra Fluid Dynamics One of the simplest problems involving external vorticity in boundary layer flows is the flow over a semi-infinite plate under a stream of uniform shear. We study the transient growth phenomenon in this flow to investigate the role of freestream shear on energy amplification, and analyse the differences with the Blasius flow. The initial optimal disturbance which triggers the maximum growth is found to be streamwise vortices, as in other shear flows. Compared to the Blasius boundary layer, higher optimum energy and larger spanwise wavelength of streamwise vortices have been observed. We provide scaling laws for the maximum optimal amplification, which is found to increase exponentially with the freestream shear gradient.
title	Transient growth in a flat plate boundary layer under a stream with uniform shear
topic	Fluid Dynamics
url	https://arxiv.org/abs/2107.08696

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