EXPERIMENTAL AND THEORETICAL INVESTIGATION OF VORTEX SHEDDING FROM SQUARE AND SHARP LEADING EDGE OF OSCILLATING FLAT PLATE.

Document Type : Original Article

Author

Dr. Eng.Associate Prof./ Power and Energy Dept/ Faculty of Eng.,/ Minia Univ.,

Abstract

ABSTRACT
This paper investigates experimentally and numerically : the vortex shedding and dynamic stall for an oscillating flat plate with sharp and square leading edge at different angles of attack. Experiments showed a drastic and different flow pattern even if the flow is laminar. Flow visualization using hydrogen bubble technique yieldes an insight into not only in the vortex generation but also it showed a reverse flow and a unique succession of vortical development over the sharp leading-edge of the oscillating plate at different frequencies and amplitudes , even at a constant Strouhal number. Pressure field has been determined experimently.
A numerical solution for flow over a pitching flat plate on the basis of a finite difference analysis of the two-dimensional Navier-Stokes equations has been employed. Numerical computation confirms that vortex shedding from flat plate with square leading-edge is caused by the impinging shear layer instability, and provides some crucial information on the vortical flow occuring near the leading-edge in conjunction with the vortex shedding mechanism. Pressure field was determined too. Comparison between experimental and computational results has been considered.

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