A study of Mach wave radiation using active control

Kearney-Fischer, Martin; Kim, J.-H.; Samimy, Mo

doi:10.1017/jfm.2011.196

Cited by 48 publications

(42 citation statements)

References 82 publications

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“…2 Further support for this phenomenon is provided by the sharpness of the compression waves observed in schlieren imagery. 9,35 Assuming that the perturbation injected by the plasma actuator is indeed localized in space and time, we have an opportunity to study the impulse response of the jet. Figure 7 depicts the relationship between the actuation and the near-field pressure at a representative location.…”

Section: The Impulse Responsementioning

confidence: 99%

The impulse response of a high-speed jet forced with localized arc filament plasma actuators

et al. 2012

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Experimental study of planar opposed jets with acoustic excitation Phys. Fluids 25, 014108 (2013) Similarity analysis of the momentum field of a subsonic, plane air jet with varying jet-exit and local Reynolds numbers Phys. Fluids 25, 015115 (2013) Electrohydrodynamic printing under applied pole-type nozzle configuration Appl. Phys. Lett. 102, 024101 (2013) Effects of fluid properties and laser fluence on jet formation during laser direct writing of glycerol solution J. Appl. Phys. 112, 083105 (2012) We present experimental and theoretical analyses of the response of high-speed, highReynolds-number, round jets to impulsive forcing with arc-filament-plasma actuators. The impulse response is obtained with forcing Strouhal numbers, based on the nozzle exit diameter and exit center line velocity, less than 0.1. The resulting phase-averaged near-field pressure signature displays a compact wave with a positive peak preceding a negative one, indicative of a large scale structure in the shear layer of the jet. Scaling laws derived by operating the jet at four subsonic Mach numbers are used to distinguish this hydrodynamic component of the phase-averaged jet response from the direct actuator noise. As the forcing frequency increases, the compact waves in the near-field pressure signal overlap each other, indicating interaction of the growing seeded structures. For this regime, the phase-averaged response is approximately replicated by linear superposition of the impulse response, thereby demonstrating the quasi-linearity of structure interaction. A novel application of linear parabolized stability theory yields a successful model of the impulse response. C 2012 American Institute of Physics. [http://dx

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Section: The Impulse Responsementioning

confidence: 99%

The impulse response of a high-speed jet forced with localized arc filament plasma actuators

et al. 2012

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“…Previous studies of flow control using LAFPAs in atmospheric pressure jet flows (M=0.9-2.0) demonstrated significant localized heating [17] and repetitive strong compression wave formation by the plasma [20,22], similar to strong compression waves produced by NS-DBD plasma actuators. LAFPA actuators also generate large-scale coherent structures in the flow [18,19,21,23] and result in significant mixing enhancement. Note that at the same forcing frequency (discharge pulse repetition rate), the effect of LAFPAs on the flow actually becomes more pronounced at lower duty cycles.…”

Section: Introductionmentioning

confidence: 99%

Dynamics of Rapid Localized Heating in Nanosecond Pulse Discharges for High Speed Flow Control

Montello

Burnette

Nishihara

et al. 2013

JFST

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Picosecond CARS spectroscopy and phased-locked schlieren imaging are used to measure time-resolved temperature and visualize compression waves in a diffuse filament, nanosecond pulsed discharge sustained between a pair of spherical electrodes in nitrogen and air at P=100 torr. The discharge generates stable plasma with high specific energy loading (up to ~0.5 eV/molecule), and with spatial dimensions sufficiently large to enable laser diagnostic studies. The results demonstrate that significant temperature rise, up to ∆T~200 K, occurs both in nitrogen and in air, on the time scale shorter than the acoustic time scale. The characteristic time for the rapid temperature rise in air, ~100 ns, is significantly shorter compared to that in nitrogen, ~1 µs. In air, a second significant temperature rise, up to ∆T~350 K, occurs on a time scale of ~100-500 µs. This "slow" temperature rise is almost entirely missing in nitrogen. Phase-locked schlieren images demonstrate a near cylindrical shape compression wave formed around the discharge filament, both in nitrogen and in air. An additional, near spherical shape compression wave is formed near the cathode, due to significant energy release in the cathode layer of the discharge. The compression waves, caused by rapid localized heating quantified by the present measurements, are similar to the ones produced by a surface nanosecond pulse discharge in atmospheric air used for high-speed flow control, where comparable temperature rise was detected previously.

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“…It is a dominant noise generation mechanism in high-speed jets. This noise generation mechanism has also been investigated extensively in the past, for example in Refs [39]- [43]. The growth, decay and propagation of the most amplified instability frequencies were examined and modeled.…”

Section: Numerical Study Of Noise Characteristics In Overexpanded Jetmentioning

confidence: 99%

Numerical Study of Noise Characteristics in Overexpanded Jet Flows

Liu¹,

Corrigan²,

Kailasanath³

et al. 2015

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Standard Form 298 (Rev. 8-98)Prescribed by ANSI Std. Z39.18Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Noise characteristics in shock-containing jets at an overexpanded jet condition have been investigated. Total temperature ratios of 1.0 (cold), 2.0, and 3.0 are considered. The cold jet is a highly screeching jet. Frequency-wavenumber Fourier analysis is employed to examine the wave characteristics of pressure waves along the lip line and also along a near-field conical surface. It is found that the radiating portion of the pressure wave intensity increases with the jet temperature, but the hydrodynamic portion is much less sensitive to the change of the jet temperature. The near-field noise intensity associated with the Mach wave radiation is observed over a large axial distance, and the Mach wave radiation extends to much higher frequencies in heated jets. The peak radiation direction in the cold jet is dominated by the axisymmetric mode, but the directions around the sideline show a much weaker azimuthal dependence. Furthermore, the axial locations of lip-line pressure peak intensities at the screech frequency are near the axial locations of shock-cell tips. A reinforcing loop between upstream/downstream propagating waves and the induced shock-cell coherent oscillatory motion is observed in the highly screeching jet. The formation of this reinforcing loop requires a match of the peak phase velocities between upstream and downstream propagating waves. This phase velocity match exists in the highly screeching cold jet, but not in the weakly screeching heated jets. It appears that the phase velocity match that sustains the reinforcing loop is important to the screech generation, and the phase velocity mismatch in heated jets is believed to be an important cause of the screech intensity reduction. REPORT TYPE 1. REPORT DATE (DD-MM-YYYY) TITLE AND SUBTITLE AUTHOR(S) PERFORMING ORGANIZATION REPORT NUMBER PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) SPONSOR / MONITOR'S ACRONYM(S) 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) SPONSOR / MONITOR'S REPORT NUMBER(S)

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A study of Mach wave radiation using active control

Cited by 48 publications

References 82 publications

The impulse response of a high-speed jet forced with localized arc filament plasma actuators

The impulse response of a high-speed jet forced with localized arc filament plasma actuators

Dynamics of Rapid Localized Heating in Nanosecond Pulse Discharges for High Speed Flow Control

Numerical Study of Noise Characteristics in Overexpanded Jet Flows

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