Fluidic Control of Aerodynamic Forces on a Body of Revolution

The aerodynamic forces and moments on a wind tunnel model of an axisymmetric bluff body are altered by induced local attachment of the separated base flow. Control is effected by an array of four integrated aft-facing synthetic jet actuators that emanate from narrow, azimuthally-segmented slots, equally distributed around the perimeter of the circular tail end within a small backward facing step that extends into a Coanda surface. The model is suspended in the wind tunnel by eight thin wires for minimal support interference with the wake. Fluidic actuation results in a localized, segmented vectoring of the separated base flow along the rear Coanda surface and induces asymmetric aerodynamic forces and moments to effect steering during flight. The aerodynamic effects associated with quasi-steady and transitory differential, asymmetric activation of the Coanda effect are characterized using direct force and PIV measurements. Nomenclature Aj actuator orifice cross-sectional area Cμ jet momentum coefficient CL lift coefficient D axisymmetric body diameter R axisymmetric body radius k turbulent kinetic energy U mean axial velocity component V mean radial velocity component U0 free stream velocity Uj average jet velocity ρ air density T jet period ReD Reynolds number ReJ jet Reynolds number xF r momentum flux ωF r vorticity flu