Wedge Shock and Nozzle Exhaust Plume Interaction in a Supersonic Jet Flow

Castner, Raymond S.; Zaman, K. B. M. Q.; Fagan, A. L.; Heath, Christopher M.

doi:10.2514/6.2014-0232

Cited by 5 publications

(3 citation statements)

References 21 publications

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“…The present study is a follow-up work with another coaxial nozzle that was used in a past experiment. 10 In the latter experiment, the effect of shocks produced by a wedge in the outer stream of the nozzle, on the development of the inner jet, was studied. The nozzle did not have a center-body.…”

Section: Motivation and Objectivementioning

confidence: 99%

“…The experiments are conducted in an open jet facility at NASA GRC, a description of which can be found in prior publications. 6,10 The nozzle, shown by the picture in Figure 2(a), is the same one as used in Castner et al 10 It is comprised of an inner nozzle with 1.40 cm exit diameter and an outer nozzle with 5.08 cm exit diameter (D o ). There is no center-body and the two nozzles are held together by a set of four struts placed in a crossed shape.…”

Section: Experimental Facilitymentioning

confidence: 99%

See 1 more Smart Citation

Experimental and computational study of tones occurring with a coaxial nozzle

Zaman

Milanović

Fagan

et al. 2019

International Journal of Aeroacoustics

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The source of audible tones occurring with a coaxial nozzle is explored experimentally as well as computationally. The hardware is comprised of an inner and an outer nozzle, without a centerbody, that are held together by a set of four struts. With increasing jet Mach number (M j), first a tone occurred at about 2550 Hz around M j ¼ 0.06. At higher M j , a tone at 5200 Hz dominated the noise spectra. The corresponding non-dimensional frequency, based on the effective thickness of the inner nozzle lip and jet exit velocity, turned out to be about 0.2, a value characteristic of Karman vortex shedding. Thus, vortex shedding from the inner nozzle lip could be linked to the tones. From a comparison of acoustic wavelengths and nozzle dimensions, as well as locations of the pressure nodes and anti-nodes from the computational results, it was inferred that the vortex shedding excited one-quarter-wave resonances within the divergent sections of the nozzle. Such resonances in the inner and the outer nozzles produced the higher and the lower frequency tones, respectively.

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Section: Motivation and Objectivementioning

confidence: 99%

Section: Experimental Facilitymentioning

confidence: 99%

Experimental and computational study of tones occurring with a coaxial nozzle

Zaman

Milanović

Fagan

et al. 2019

International Journal of Aeroacoustics

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“…3 In the LES work the e↵ects of the shock on the turbulent characteristics of the shear layer were identified. Numerical studies of oblique shock/plume interaction using both inviscid and RANS analyses have been reported recently, 4,5 in which an in-depth code-to-code comparison was performed. In the present work, focus is placed on proper overset grid generation for accurate CFD prediction of oblique shock/plume interaction using RANS analysis, and investigating the physical mechanism of oblique shock deflection as the shock travels across a supersonic jet.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulations of Shock/Plume Interaction Using Structured Overset Grids

Housman

Kiris

2015

33rd AIAA Applied Aerodynamics Conference

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Computational simulations using structured overset grids with the Launch Ascent and Vehicle Aerodynamics (LAVA) solver framework are presented for predicting oblique shock/plume interaction e↵ects to near-field sonic boom signatures. Standard second-order accurate as well as higher-resolution numerical discretizations are utilized and compared in the study. The numerical approach is compared with supersonic wind-tunnel data for three cases. The cases include an empty wind-tunnel at the operating conditions, an isolated shockgenerating diamond wedge within the tunnel, and a nozzle with diamond wedge configuration at five di↵erent nozzle pressure ratios. Solution sensitivity to numerical discretization is analyzed. Favorable comparisons between the computational results and experimental data of near-field pressure signatures are obtained. A simple prediction method for plume induced shock deflection is developed and results are compared with the CFD data.

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Plume and Shock Interaction Effects on Sonic Boom in the 1-foot by 1-foot Supersonic Wind Tunnel

Castner

Elmiligui

Cliff

et al. 2015

53rd AIAA Aerospace Sciences Meeting

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The desire to reduce or eliminate the operational restrictions of supersonic aircraft over populated areas has led to extensive research at NASA. Restrictions are due to the disturbance of the sonic boom, caused by the coalescence of shock waves formed by the aircraft. A study has been performed focused on reducing the magnitude of the sonic boom N-wave generated by airplane components with a focus on shock waves caused by the exhaust nozzle plume. Testing was completed in the 1-foot by 1-foot supersonic wind tunnel to study the effects of an exhaust nozzle plume and shock wave interaction. The plume and shock interaction study was developed to collect data for computational fluid dynamics (CFD) validation of a nozzle plume passing through the shock generated from the wing or tail of a supersonic vehicle. The wing or tail was simulated with a wedgeshaped shock generator. This test entry was the first of two phases to collect schlieren images and off-body static pressure profiles. Three wedge configurations were tested consisting of strut-mounted wedges of 2.5degrees and 5-degrees. Three propulsion configurations were tested simulating the propulsion pod and aft deck from a low boom vehicle concept, which also provided a trailing edge shock and plume interaction. Findings include how the interaction of the jet plume caused a thickening of the shock generated by the wedge (or aft deck) and demonstrate how the shock location moved with increasing nozzle pressure ratio. Nomenclature D= test nozzle outer diameter, inches NPR = nozzle pressure ratio, Pt / P∞ P = local static pressure, psia Pt = total pressure in nozzle, psia P∞ = free stream static pressure, psia ΔP/P = normalized static pressure, (P -P∞)/ P∞ x = axial distance from jet simulator nozzle exit plane, inches y = vertical distance from nozzle centerline, inches

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Wedge Shock and Nozzle Exhaust Plume Interaction in a Supersonic Jet Flow

Cited by 5 publications

References 21 publications

Experimental and computational study of tones occurring with a coaxial nozzle

Experimental and computational study of tones occurring with a coaxial nozzle

Numerical Simulations of Shock/Plume Interaction Using Structured Overset Grids

Plume and Shock Interaction Effects on Sonic Boom in the 1-foot by 1-foot Supersonic Wind Tunnel

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