Author : K.Ashokachary 1
Date of Publication :7th August 2016
Abstract: Reduction in recirculation zone size in suddenly expanded geometries is one of the major issues to deal with. After the flow encountering the sudden expansion geometry it gets many complex features like separation, recirculation, attachment and reverse flow. In the present study, flow over such geometries with blowing and suction scenario are studied for Lmax/Lmin = 5.The operating conditions for each model vary with water being blown at different levels of water and single and double injections as well. Flow patterns for all the models under consideration are captured. Variation in the position of separation point is observed, i.e. the separation point shifts towards downstream of the channel and attachment point shifts towards upstream direction, which is more desirable for sudden expanded geometries.By using blowing technique, recirculation zone reduces about 12 times. Strength of the vortex also changed with the configurations considered. Such findings with different height ratios and blowing techniques provide researchers with valuable guidelines for improving the design and operation of various fluidics used to study flow in channels
Reference :
-
- C. Dales, M.P. Escudier, R.J. Poole, “Asymmetry in the turbulent flow of a viscoelastic liquid through an axisymmetric sudden expansion”, J. Non-Newtonian Fluid Mech. 125 (2005) 61–70
- G.C. Layek, C. Midya, S. Mukhopadhyay, “Effects of Suction and Blowing on Flow Separation in a Symmetric Sudden Expanded Channel”, Modelling and Control, 2008, Vol. 13, No. 4, 451–465
- Ä°hsan DaÄŸtekin and Mazhar Ünsal, „Numerical analysis of axisymmetric and planar sudden expansion flows for laminar regime‟, International Journal for Numerical Methods in Fluids, Vol. 65, No. 9, pp. 1133-1144, 2011
- Kaushik V.V.R, Ghosh Sumana, D.A.S.Gargi, Kumar Das Prasanta, CFD simulation of core annular flow through sudden contraction and expansion, Journal of petroleum science & engineering,Vol. 86-87, pp. 153- 164, 2012.