A set of flow control approaches have been recently investigated for improved aerodynamic performance in a range of transport aircraft applications. Active Flow Control concepts are employed for reducing operational hazards during airplane ground maneuvering, alleviating trailing wakes for higher air traffic efficiency and improving takeoff and landing performance. Computational Fluid Dynamics has been extensively used to gain insight into complex flows subject to various modes of actuation and to develop promising techniques of flow control. The use of numerical simulations is especially important in scenarios involving powered systems, intricate vortex structures, separated flows, and active flow control devices, where alternative testing is extremely expensive and often impractical.

No abstract

A computational method for predicting the aerodynamic performance of a vertical tail due to active flow control has been developed. Enhanced directional control using flow control technology can potentially result in reduced fuel burn and improved airplane performance. Results of the validation for various flow conditions, actuation parameters and port layouts using a representative vertical tail configuration are used to establish the accuracy of the numerical tool. A practical approach to facilitate preliminary evaluations of active flow control with quick computational turnaround is proposed. Aspects of integration into a vertical tail are presented and guidelines for preferred modes of actuation are put forth.

No abstract

No abstract

Enhanced high-lift airplane performance using active flow control is investigated. A computational fluid dynamics process has been developed for flow simulations in conjunction with active control. The analysis tool has been validated with experimental data and it has been extensively used to gain insight into high-lift flows that are subject to various modes of actuation. The computational method has been used for a methodical buildup of distributed flow control systems with substantial gains in aerodynamic efficiency. The versatility of the distributed active flow control offers a high payoff for the practical airframe integration of high-lift systems.= reduced forcing frequency, f c=U 1 f = actuator frequency, Hz h = actuator slot width L=D = lift-to-drag ratio U j =U 1 = ratio of jet actuator peak velocity to freestream velocity u x = streamwise component of the velocity vector = angle of attack flap = flap deflection angle j = 1 = ratio of jet actuator density to freestream density

No abstract

No abstract