ENHANCEMENT PERFORMANCE OF WIND TURBINE BLADE BY COMPARISON STUDY OF SUCTION AND BLOWING TECHNIQUESUSING SEP METHOD

Abstract

In this work a new concept of flow separation control mechanism has been introduced to improve the aerodynamic characteristics of an airfoil. Control of flow separation over an airfoil at low Reynolds number is theoretically simulated under the effects of suction and blowing, based on the computation of Reynolds-average Navier-Stocks equations(the solution of each set of equations is achieved by application of the SEP(strong explicit procedure)solver) is carried out. Using Finite Volume Method to solve the governing equations on a body, so, a numerical model is developed. The suction and blowing control mechanism appears to be suppression of the separation bubble and reduction of the upper surface pressure to increase the lift and decrease the drag. To make section model, NACA 4421 airfoil has been chosen. In present study, the theoretical are performed with different angle of attack (20º, 22º, 23º), Uj/U (A) =6 and different chord (1c,0.9c,0.8c,0.7c). The theoretical results show that the flow separation control is possible by the proposed mechanism and benefits can be achieved by suction and blowing (for suction position at the end of the chord (0.8c) and for blowing position at the begging of the chord (0.1c)). The section performance is significantly improved due to control of flow separation by suction and blowing. It has also been found that the lift increases about 14% at the angle of attack 20º, 22ºand 23º and seen that the blowing is better than the suction.