Experimental and Numerical Investigation of Active Control of Inlet Ducts

Vaccaro, John C.; Sahni, Onkar; Olles, Joseph D.; Jansen, Kenneth E.; Amitay, Michael

doi:10.1260/175682509788913317

Cited by 18 publications

(8 citation statements)

References 24 publications

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“…Every actuator was found effective in reducing flow separation, but swirling movements in the AIP were always magnified. An example of the application of pulsed jet to a very aggressive bidimensional S-duct configuration can be found in [13]. The authors proved pulsed blowing through a slot to be more efficient than continuous blowing for the control of flow separation at a Mach number of 0.45.…”

Section: Introductionmentioning

confidence: 99%

Flow Control by Pulsed Jet in a Curved S-Duct: A Spectral Analysis

Garnier

2015

AIAA Journal

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This paper presents an experiment of flow control by supersonic pulsed jets in a very aggressive S-duct typical of modern fighter aircraft engine inlet ducts. The Mach number in the aerodynamic interface plane ranges from 0.2 to 0.4, which is realistic from an application point of view. It was shown that, with continuous blowing, the flow could be fully reattached. The sensitivity of the distortion coefficient to the jet frequency was also clearly evidenced. Surprisingly, it is recommended to avoid actuating the jets at the natural frequencies present in the separated zone of the uncontrolled flow. Besides, it is observed that pulsed jets actuation increases the unsteady flow distortion. Furthermore, in the uncontrolled flow, a lateral movement of the structures associated with high total pressure losses in the aerodynamic interface plane was highlighted. Nomenclature c = velocity of sound, m∕s D 1 = inflow section diameter, mm D 2 = exit section diameter, mm d = jet diameter, mm d a = average duct diameter, mm Ef = spectral density of power, Pa 2 ∕Hz f = frequency, Hz H = offset of the outlet section with respect to the inflow section, mm L = jet stroke length, m L duct = distance from the bell mouth to the translating plug, mm L sep = separation length estimated from the pressure distribution, mm Ma = averaged Mach number in the aerodynamic interface plane Ma 1= isentropic Mach number in the inflow section P dyn = dynamic pressure in the inflow section, Pa Pi = stagnation pressure in the aerodynamic interface plane, Pa Pi 0 = external atmospheric stagnation pressure, Pa Ps 1 = inlet static pressure, Pa Q d = duct mean mass flow rate, g∕s Q dyn = dynamic pressure in the aerodynamic interface plane, Pa Q j = total jet mean mass flow rate, g∕s T = forcing period, s (t, r, n) = frame of reference local to the jets U 1 = velocity in the inflow section, m∕s x, y, z = longitudinal, vertical, and spanwise directions (respectively), mm α = jet pitch angle, deg β = jet skew angle, deg η = duct mean efficiency Φ = angle along the duct circumference, deg <> = operator that denotes an averaging on the 40 pressure sensors in the aerodynamic interface plane

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Section: Introductionmentioning

confidence: 99%

Flow Control by Pulsed Jet in a Curved S-Duct: A Spectral Analysis

Garnier

2015

AIAA Journal

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“…Typically, forcing frequencies are introduced in flow control to mitigate separations by manipulating flow instabilities. Since steady blowing could already eliminate centerline separation, there was no advantage to introducing frequencies at this time-averaged mass forcing ratio of 0.7% (however, note that in some cases unsteady actuation can reduce the forcing level needed for reattachment, as was shown in our previous work, Vaccaro et al (2009) and on airfoils by Seifert et al (1993)). In the present case, the forced flow field Baseline Forced Fig.…”

Section: Unsteady Flow Fieldmentioning

confidence: 65%

“…Most active flow control research has focused on blowing or suction from the inlet's surface. Blowing devices are found in many forms: Coanda-type steady or unsteady ejectors (McElwain, 2002;Luers, 2003;Tournier et al, 2006;Vaccaro et al, 2009), microjets (Hamstra et al, 2000;Kumar and Alvi, 2006;Reynolds and Reeder, 2009), vortex generator jets (Pradeep, 2004;Owens et al, 2006;Sullerey et al, 2006;Rabe Scribben et al, 2006), and synthetic jet actuators (Amitay and Glezer, 2002).…”

Section: Introductionmentioning

confidence: 99%

Experimental and numerical investigation on steady blowing flow control within a compact inlet duct

Vaccaro

Elimelech

Chen

et al. 2015

International Journal of Heat and Fluid Flow

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“…The effectiveness of curved-inlet designs combined with various flow control techniques in maintaining uniform flow at the compressor face has been investigated by Wellborn et al [2]. More recent investigations were carried out in references Rabe et al [3], Taskinoglu et al [4], Vaccaro et al [5], and Gerolymos et al [6].…”

Section: Introductionmentioning

confidence: 99%

Effect of Aspect Ratio on Flow Through Serpentine Nozzles

Reynolds

Reeder

2012

Journal of Aircraft

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The flowfields for two rectangular cross-sectional nozzles with two in-plane 90 deg bends were investigated both experimentally and computationally. The cross-sectional planform of the two nozzles were of opposite aspect ratios (2:1 and 1:2). The Reynolds number (based upon the hydraulic diameter and mean velocity within the nozzle) was 1:4 10 4 , providing a Dean number of 8400 (based upon radius of curvature at the centerline of the nozzle). The experimental portion of the study was conducted by three-component laser Doppler velocimetry using a five-beam probe. A computational study was performed on the interior of the nozzle using a commercial code that employed a Reynolds stress model. With noted exceptions, good correlation was observed between the computational and experimental solutions. Secondary-flow velocities at the nozzle exit revealed evidence of a complex pattern of streamwise vortices generated by the two bends. It was found that despite the common Dean number, the difference in aspect ratio led to substantially different velocity fields. The flow was dominated by a single pair of counterrotating streamwise vortices in one case, whereas its counterpart yielded a complex pattern of multiple smaller vortices.

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Experimental and Numerical Investigation of Active Control of Inlet Ducts

Cited by 18 publications

References 24 publications

Flow Control by Pulsed Jet in a Curved S-Duct: A Spectral Analysis

Flow Control by Pulsed Jet in a Curved S-Duct: A Spectral Analysis

Experimental and numerical investigation on steady blowing flow control within a compact inlet duct

Effect of Aspect Ratio on Flow Through Serpentine Nozzles

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