Drag reduction on a large-scale nacelle using a micro-blowing technique

Tillman, T. G.; Hwang, Danny P.

doi:10.2514/6.1999-130

Cited by 19 publications

(12 citation statements)

References 5 publications

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“…Analysis from this research also shows that the interaction between blowing flow and the boundary layer is limited to a region up to y" = 19 [34]. This is similar to the conclusion from the experiments [25,26] that the blowing flow penetrates the boundary layer out to an upper limit near y + = 15.…”

Section: Large Eddynattice Boltmnn Simulation (2002-2004 [32-341)supporting

confidence: 82%

“…Since the LFC experiment used one of the MBT skins (GAC1897), a slight modification of the air suction system was sufficient to provide a uniform amount of blowing air for an evaluation of the MBT. After back-to-back experiments of the LFC test and the MBT test on the same nacelle, the following assessment of comparison was indicated [25]: 'ZFC is operationally complicated in that the process is highly sensitive to surface quality. Small (on the order of 0.0254 mm) imperfections in the nacelle surface can render LFC difficult or impossible to accomplish.…”

Section: Drag Reduction On a Large-scale Nacelle (1997 125261)mentioning

confidence: 99%

“…Therefore, challenges still remain as to the cost associated with the manufacture, installation, and maintenance of suction skins and the suction bleed source. In addition, the surface quality requirements (under 0.0254 mm perfection) and the technology for insect and debris avoidance remain challenging tasks [25].…”

mentioning

confidence: 99%

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Review of research into the concept of the microblowing technique for turbulent skin friction reduction

Hwang

2004

Progress in Aerospace Sciences

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A new technology for reducing turbulent skin friction, called the Microblowing Technique (MBT), is presented. Results from proof-of-concept experiments show that this technology could potentially reduce turbulent skin friction by more than 50% of the skin friction of a solid flat plate for subsonic and supersonic flow conditions. The primary purpose of this review paper is to provide readers with information on the turbulent skin friction reduction obtained from many experiments using the MBT. Although the MBT has a penalty for obtaining the microblowing air associated with it, some combinations of the MBT with suction boundary layer control methods are an attractive alternative for a real application. Several computational simulations to understand the flow physics of the MBT are also included. More experiments and computational fluid dynamics (0) computations are needed for the understanding of the unsteady flow nature of the MBT and the optimization of this new technology.

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Section: Large Eddynattice Boltmnn Simulation (2002-2004 [32-341)supporting

confidence: 82%

Section: Drag Reduction On a Large-scale Nacelle (1997 125261)mentioning

confidence: 99%

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Review of research into the concept of the microblowing technique for turbulent skin friction reduction

Hwang

2004

Progress in Aerospace Sciences

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“…The micro-blowing concept was successfully implemented in the case of flow around a curved surface forming the large-scale model of the engine nacelle at the Reynolds numbers approaching to the flight level [69]. In some areas of the surface, the friction drag can be reduced by around 50%, at relative low blowing coefficient values.…”

Section: Blowing Through the Wall With Uniformly Distributed Perforatmentioning

confidence: 99%

Current state and prospects of researches on the control of turbulent boundary layer by air blowing

Kornilov

2015

Progress in Aerospace Sciences

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“…The quest for efficient flow control for improved vehicle aerodynamics has led to the development of many ingenious actuators and control techniques over the years [1]. Examples of flow control include passive and active vortex generators [1,2], suction [3], blowing [4], oscillatory blowing/suction [5], synthetic jet actuators [6], and dielectric barrier discharge (DBD) plasma actuators [7], to name a few. Although there are a number of different types of flow control actuators, it is becoming increasingly clear that for an actuator to buy its way onto an air vehicle, it not only needs to demonstrate the ability to generate the forces necessary for control, but also an overall improvement in the aerodynamic and structural efficiencies of the vehicle, relative to the conventional control system.…”

mentioning

confidence: 99%

Plasma Actuators for Hingeless Aerodynamic Control of an Unmanned Air Vehicle

Patel¹,

Ng²,

Vasudevan³

et al. 2007

Journal of Aircraft

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The use of dielectric barrier discharge plasma actuators for hingeless flow control over a 47-deg 1303 unmanned combat air vehicle wing is described. Control was implemented at the wing leading edge to provide longitudinal control without the use of hinged control surfaces. Wind-tunnel tests were conducted at a chord Reynolds number of 4:12 10 5 and angles of attack ranging from 15 to 35 deg to evaluate the performance of leading-edge plasma actuators for hingeless flow control. Operated in an unsteady mode, the actuators were used to alter the flowfield over the lee-side wing to modify the aerodynamic lift and drag forces on the vehicle. Multiple configurations of the plasma actuator were tested on the lee side and wind side of the wing leading edge to affect the wing aerodynamics. Data acquisition included force-balance measurements, laser fluorescence, and surface flow visualizations. Flow visualization tests mainly focused on understanding the vortex phenomena over the baseline uncontrolled wing to aid in identifying optimal locations for plasma actuators for effective flow manipulation. Force-balance results show considerable changes in the lift and drag characteristics of the wing for the plasma-controlled cases compared with the baseline cases. When compared with the conventional traditional trailing-edge devices, the plasma actuators demonstrate a significant improvement in the control authority in the 15-to 35-deg angle-of-attack range, thereby extending the operational flight envelope of the wing. The study demonstrates the technical feasibility of a plasma wing concept for hingeless flight control of air vehicles, in particular, vehicles with highly swept wings and at high angles of attack flight conditions in which conventional flaps and ailerons are ineffective. Nomenclature = angle of attack, deg b = wing span, m C D = drag coefficient C L = lift coefficient c = mean aerodynamic chord, m F = nondimensional frequency of the actuator f mod = modulation frequency, Hz L sep = streamwise extent of the separation zone, m Re c = Reynolds number based on the mean chord and freestream velocity St = Strouhal number based on the mean chord U 1 = freestream velocity at the entrance to the test section, m=s x = distance from the leading edge, m y = spanwise distance from the centerline, m

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Drag reduction on a large-scale nacelle using a micro-blowing technique

Cited by 19 publications

References 5 publications

Review of research into the concept of the microblowing technique for turbulent skin friction reduction

Review of research into the concept of the microblowing technique for turbulent skin friction reduction

Current state and prospects of researches on the control of turbulent boundary layer by air blowing

Plasma Actuators for Hingeless Aerodynamic Control of an Unmanned Air Vehicle

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