Wind Tunnel Testing of High Efficiency Low Power (HELP) Actuation for Active Flow Control

The design, fabrication and installation of an approximately 1/6 scale model of an aircraft vertical stabilizer for research in Active Flow Control (AFC) is discussed. Highlighted are the unique design requirements of wind tunnel models, the specialized fabrication techniques employed to create them and the required close collaboration between industry, government and three academic institutions. The design of the model involves often competing constraints imposed by structural, instrumentation, aerodynamic, manufacturability and research-agenda considerations as well as cost and schedule. Instrumentation requires hundreds of pressure ports and six-axis force/torque sensing. Aerodynamic considerations necessitate high manufacturing precision, highly-skilled fabrication techniques and careful observance of model geometry throughout the design and fabrication processes. A scale model of a vertical stabilizer for AFC research was successfully designed, fabricated and deployed. The collaboratively designed model satisfies the structural, aerodynamic and research design constraints, and furthers the state of the art in Active Flow Control research.

Download Full-text

Aerodynamic Characteristics of a Blended-Wing-Body Aircraft With A Serpentine Inlet Using Flow Control Techniques

10.1115/gt2021-60335 ◽

2021 ◽

Author(s):

Min-Sik Youn ◽

Youn-Jea Kim

Keyword(s):

Flow Control ◽

Flow Separation ◽

High Efficiency ◽

Active Flow Control ◽

Quantitative Measure ◽

Aerodynamic Characteristics ◽

Interface Plane ◽

Flow Distortion ◽

Blended Wing Body ◽

Active Flow

Abstract Demands of a modern aircraft regarding its aerodynamic performance and high efficiency are ever-growing. An S-shaped inlet, as known as a serpentine duct, plays a significant role in increasing fuel efficiency. Recently, the serpentine duct is commonly employed for military aircraft to block the front of the jet engine from radar. However, delivering a non-uniformly distorted flow to the engine face (aerodynamic interface plane, AIP) though a serpentine duct is inevitable due to the existence of flow separation and swirl flow in the duct. The effect of distortion is to cause the engine compressor to surge; thus, it may impact on the life-cycle of aircraft engine. In this study, aerodynamic characteristics of a serpentine duct mounted on a blended-wing-body (BWB) aircraft was thoroughly investigated to determine where and how the vortex flow was generated. In particular, both passive and active flow control were implemented at a place where the flow separation was occurred to minimize the flow distortion rate in the duct. The passive and active flow control systems were used with vortex generator (VG) vanes and air suctions, respectively. A pair of VG s have been made as a set, and 6 sets of VG in the serpentine duct. For the active flow control, 19 air suctions have been implemented. Both flow control devices have been placed in three different locations. To evaluate the performance of flow control system, it is necessary to quantify the flow uniformity at the AIP. Therefore, coefficient of distortion, DC(60) was used as the quantitative measure of distortion. Also, change in DC(60) value while the BWB aircraft is maneuvering phase was analyzed.

Download Full-text

Numerical and Experimental Wind Tunnel and Flight Testing of Active Flow Control for Modified NACA 643-618 Airfoil

53rd AIAA Aerospace Sciences Meeting ◽

10.2514/6.2015-1705 ◽

2015 ◽

Cited By ~ 1

Author(s):

James Dianics ◽

Duncan Ohno ◽

Stefan Fuggmann ◽

Jonas Lay ◽

Daniel Heim ◽

...

Keyword(s):

Wind Tunnel ◽

Flow Control ◽

Active Flow Control ◽

Flight Testing ◽

Active Flow

Download Full-text

Fluidic actuators for separation control at the engine/wing junction

Aircraft Engineering and Aerospace Technology ◽

10.1108/aeat-01-2017-0013 ◽

2017 ◽

Vol 89 (5) ◽

pp. 709-718 ◽

Cited By ~ 2

Author(s):

Philipp Schloesser ◽

Michael Meyer ◽

Martin Schueller ◽

Perez Weigel ◽

Matthias Bauer

Keyword(s):

Wind Tunnel ◽

Flow Control ◽

Flow Separation ◽

Mass Flux ◽

Large Scale ◽

Active Flow Control ◽

Wind Tunnel Test ◽

Local Flow ◽

Content Type ◽

Active Flow

Purpose The area behind the engine/wing junction of conventional civil aircraft configurations with underwing-mounted turbofans is susceptible to local flow separation at high angles of attack, which potentially impacts maximum lift performance of the aircraft. This paper aims to present the design, testing and optimization of two distinct systems of fluidic actuation dedicated to reduce separation at the engine/wing junction. Design/methodology/approach Active flow control applied at the unprotected leading edge inboard of the engine pylon has shown considerable potential to alleviate or even eliminate local flow separation, and consequently regain maximum lift performance. Two actuator systems, pulsed jet actuators with and without net mass flux, are tested and optimized with respect to an upcoming large-scale wind tunnel test to assess the effect of active flow control on the flow behavior. The requirements and parameters of the flow control hardware are set by numerical simulations of project partners. Findings The results of ground test show that full modulation of the jets of the non-zero mass flux actuator is achieved. In addition, it could be shown that the required parameters can be satisfied at design mass flow, and that pressure levels are within bounds. Furthermore, a new generation of zero-net mass flux actuators with improved performance is presented and described. This flow control system includes the actuator devices, their integration, as well as the drive and control electronics system that is used to drive groups of actuators. Originality/value The originality is given by the application of the two flow control systems in a scheduled large-scale wind tunnel test.

Download Full-text