DRAG COEFFICIENT REDUCTION IN CYLINDRICAL BODIES USING A DOWNSTREAM WAVY FIN

Mohammed Ali, Kamal

	DRAG COEFFICIENT REDUCTION IN CYLINDRICAL BODIES USING A DOWNSTREAM WAVY FIN
AL-TAQANI
Article 1, Volume 24, Issue 6, 2011, Pages 25-32
Author
kamal Mohammed Ali
Abstract
An investigation was performed to show how drag force and hence drag coefficient will be reduced when using a wavy shape fin attached to the trailing edge of a cylindrical body fitted normally in air stream of an open loop blower type wind tunnel. Using wavy fin attached to cylinder body to offset any probable flow separation which may be occurred when using straight fins. Drag force measured by using momentum equation between upstream and downstream to the cylinder , this done by measuring differential pressure at a ( 10 10 ) mesh of points chosen upstream and downstream . Work was done by testing the cylinder with no fin first then attaching straight fin and finally by attaching wavy fin in order to make result comparable. Investigation was done in sub-critical flow regime with variable air speeds which creates of (Re) from ( 410³ and 16*10³ ) with seven increments, and with 10 cm cylinder diameter and 10 cm straight fin width i.e. ( L/d = 1 ) and apparent ratio of 0.5 . Results are then compared with that of no fin and with straight fin .Results show that to a certain limit of (Re) there is a considerable reduction in drag coef. compared with straight and no fin cylinder then it tends to decrease and become constant beyond that limit ,and there is a high reduction at low Reynolds number
Keywords
Drag reduction; fin; wind tunnel; cylinder

Statistics Article View: 175 PDF Download: 100