Experimental investigation of small wind turbine airfoil under pulsate suction jet

Recently there has been a great concern in applying active airflow control to Small wind turbine blade airfoils to improve the aerodynamic characteristics. One of these novel methods is the application of pulsed air jets. The current study is involved in the experimental investigation of the effect of the pulse flow control on the performance parameters of the NACA 0012 airfoil at the Reynolds number (Re) range from 0.5 x 105 to 1.4 x 105. The pulsed flow was studied at frequencies of 3, 6, and 9 Hz while keeping the suction pressure at -1200 Pa. The results were compared to the standard clean NACA 0012 airfoil. The results indicated an increment in lift coefficient at frequency 9 Hz at Re of 0.5 x 105 with Smaller angles of attack below 12o while the pulsating frequency 3 Hz has the maximum lift coefficient with an increment of 6.14%. At Re of 1.1 x 105 the pulsate frequency 9 Hz has the maximum lift coefficient with an increment of 16.33% with a delay of the stall angle of attack by one degree. At Re of 1.4 x 105 the reduction in drag coefficient was observed at different pulse-controlled frequencies where it reached 7.5%, 5.1%, and 27.4% at frequencies f = 3 Hz, f = 6 Hz, and f = 9 Hz respectively.