Suction and pulsed blowing interaction with a laminar boundary layer

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.