Suction and Pulsed Blowing Interaction with a Laminar Boundary Layer L. Marom 1 , V. Palei 2 , and A. Seifert 3 , Tel Aviv University, Tel Aviv 69978, Israel This work presents ongoing experimental study towards developing fundamental understanding of suction and oscillatory blowing (SaOB) flow control mechanisms and provide bench-mark data for validation of practical CFD simulation methodologies for complex unsteady active flow control systems. Experimental studies were conducted on steady suction alone, starting from a single hole to multiple holes and on SaOB actuators’, and pulsed blowing alone during external interaction with a laminar, zero pressure gradient boundary layer. The experiment uses hot-wire measurements conducted in a laminar boundary layer wind tunnel with steady suction and pulsed blowing from a single actuator. The suction experiments show that the suction holes’ geometry and configuration is an important factor in determining the structure and stability of the downstream laminar boundary layer flow-field. Measurements of oscillatory blowing jets (without suction) interacting with a laminar boundary layer demonstrate that this flow control method produces unsteady spanwise and streamwise structures which can be used as an effective boundary layer separation tool. I. Nomenclature A = area of suction holes A i = phase-locked coefficients C f = skin friction coefficient d = suction hole diameter f = actuator oscillation frequency H = boundary layer shape factor L FB = length of feedback tube L n = nozzle width P in = air supply pressure at actuator inlet P suc = static pressure in suction chamber Q = volume flow rate of suction Re x = Reynolds number based on streamwise distance Re δ* = Reynolds number based on nozzle width s = suction hole spanwise spacing U j = jet velocity U s = suction velocity 1 Research Assistant, School of Mechanical Engineering, Faculty of Engineering, Levanon Street. 2 Research Engineer, School of Mechanical Engineering, Faculty of Engineering, Levanon Street. 3 Head, School of Mechanical Engineering, Faculty of Engineering, Levanon Street, Associate Fellow AIAA.