Unsteady separation and vortex shedding from a laminar separation bubble over a bluff body

Das, SP and Srinivasan, U and Arakeri, JH (2013) Unsteady separation and vortex shedding from a laminar separation bubble over a bluff body. In: Journal of Fluids and Structures, 40 . pp. 233-245.

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Abstract

Boundary layers are subject to favorable and adverse pressure gradients because of both the temporal and spatial components of the pressure gradient. The adverse pressure gradient may cause the flow to separate. In a closed loop unsteady tunnel we have studied the initiation of separation in unsteady flow past a constriction (bluff body) in a channel. We have proposed two important scalings for the time when boundary layer separates. One is based on the local pressure gradient and the other is a convective time scale based on boundary layer parameters. The flow visualization using a dye injection technique shows the flow structure past the body. Nondimensional shedding frequency (Strouhal number) is calculated based on boundary layer and momentum thicknesses. Strouhal number based on the momentum thickness shows a close agreement with that for flat plate and circular cylinder.

Item Type:	Journal Article
Publication:	Journal of Fluids and Structures
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Unsteady Separation; Unsteady Boundary Layers; Vortex Formation; Strouhal Number
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	21 Sep 2013 13:06
Last Modified:	21 Sep 2013 13:06
URI:	http://eprints.iisc.ac.in/id/eprint/47261

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