Experimental Characterization of a Novel Integrated Flow Control Method
Abstract
Flow control methods can be used in many areas of aerodynamics such as
separation control, wind turbines, landing gears and micro satellites. Flow separation in
the boundary layer is one of the fundamental problems of aerodynamics. Separated flow
in the airfoil boundary layer causes the aircraft to stall. Blowing and Dielectric Barrier
Discharge (DBD) Plasma Actuator based techniques have proven successful in limited
applications of separation control. However, Blowing techniques require high pressure
source and Plasma Actuators are only successful in low speed application. The current
research incorporated experimental techniques in characterizing a novel integrated flow
control method by combining blowing flow control with Dielectric Barrier Discharge
(DBD) Plasma Actuator based flow control. Integrated control would be applicable in
wider flow domain than individual plasma or blowing. Initially, characterization
experiments were performed as a proof of concept for the integrated control and then,
the integrated control was applied in airfoil separation control. Characterization
experiments were performed with a vertically fired cylindrical jet having plasma
actuator around the jet periphery. The cylindrical jet was used to simulate blowing. The
results obtained from characterization experiments indicated 63% reduction in blowing
ratio due to plasma addition. The integrated control was placed on NACA 0025 airfoil
with blow opening at 25% x/C and plasma actuator at 25.5% x/C location. Windtunnel
tests were performed at freestream velocities of 3 mis and 4.5 mis with airfoil angle set
at 10 degree. Results indicate 110% increase in airfoil near wall velocity for 3mls when integrated control was applied. Separation was experienced in the region when other
flow control methods were used.