Flow Separation Control on a Full-Scale Vertical Tail Model using Sweeping Jet Actuators

Abstract

This paper describes test results of a joint NASA/Boeing research effort to advance Active Flow Control (AFC) technology to enhance aerodynamic efficiency. A full-scaleBoeing 757 vertical tail model equipped with sweeping jets AFC was tested at the National Full-Scale Aerodynamics Complex 40-by 80-Foot Wind Tunnel at NASA Ames Research Center. The flow separation control optimization was performed at 100 knots, a maximum rudder deflection of 30°, and sideslip angles of 0° and -7.5°. Greater than 20% increments in side force were achieved at the two sideslip angles with a 31-actuator AFC configuration. Flow physics and flow separation control associated with the AFC are presented in detail. AFC caused significant increases in suction pressure on the actuator side and associated side force enhancement. The momentum coefficient (C µ ) is shown to be a useful parameter to use for scaling-up sweeping jet AFC from sub-scale tests to full-scale applications. Reducing the number of actuators at a constant total C µ of approximately 0.5% and tripling the actuator spacing did not significantly affect the flow separation control effectiveness. NomenclatureAFC = active flow control APU = auxiliary power unit c = total local chord length CFD = computational fluid dynamics C p = pressure coefficient C y = side force coefficient C Yn = normalized side force coefficient relative to baseline (AFC off) C µ = momentum coefficient, % ERA = Environmentally Responsible Aviation LE = leading edge M ∞ = free stream Mach number NFAC = National Full-Scale Aerodynamics Complex Re = Reynolds number based on mean aerodynamic chord U ∞ = free stream velocity, knots x = streamwise direction β = sideslip angle, degrees δ Rudder = flap deflection angle, degrees %ΔC y = % difference in C y with respect to AFC off, 100%*(C y -C y, AFC off )/ C y, AFC off Downloaded by UNIVERSITY OF TORONTO on July 31, 2015 | http://arc.aiaa.org |

Performance Enhancement of an Airfoil Model with a Control Surface using Synthetic Jets

“…Results showed that the performance enhancement seen on subscale models exists on full-scale tails and that active flow control is a viable option for future aerospace usage. Andino et al 22 and Lin et al discussed actuator spacing results and reported that the trends are based on momentum coefficient. Lin et al 24 also discussed flight testing with AFC on the Boeing 757 ecoDemonstrator where the results indicated flow reattachment over the rudder and a smoother flight.…”

“…Their work included cases at flight Reynolds numbers. Full-scale experiments at flight Reynolds numbers were carried out by Andino et al 22 , Whalen et al 23 , and Lin et al 24 on a Boeing 757 vertical tail retrofit with sweeping jets. Results showed that the performance enhancement seen on subscale models exists on full-scale tails and that active flow control is a viable option for future aerospace usage.…”

Wing Tip Drag Reduction at Nominal Take-Off Mach Number: An Approach to Local Active Flow Control with a Highly Robust Actuator System

“…A review of different types of fluid amplifiers, and their application for flow control is given in [14]. Impressive results were obtained using this actuator type, e.g., in experiments to improve the rudder effectiveness of a full-scale vertical tail plane [15,16].…”

Wing Tip Drag Reduction at Nominal Take-Off Mach Number: An Approach to Local Active Flow Control with a Highly Robust Actuator System

“…A review of different types of fluid amplifiers and their application for flow control is given in [14]. Impressive results were obtained using this actuator type, e.g., in experiments to improve the rudder effectiveness of a full-scale vertical tail plane [15,16]. In this paper, we study the effect of the spanwise distribution of the actuation and investigate the effect of the momentum coefficient and jet velocity ratio on the aerodynamic performance of the outer wing model.…”