Shock wave control by nonequilibrium plasmas in cold supersonic gas flows

Merriman, Samuel; Ploenjes, Elke; Palm, Peter; Adamovich, Igor V.

doi:10.2514/3.14899

Cited by 16 publications

(27 citation statements)

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“…Although at these conditions a much smaller fraction of the input power goes to vibrational excitation, 28 the temperature rise in the rf discharge remains rather modest. Previous measurements 18 show that the temperature rise in the inviscid core of an M D 2, 30% N 2 -70% He ow excited by a 200-W rf discharge is only 1T D 15 K.…”

Section: Resultsmentioning

confidence: 91%

“…Previous measurements 18 showed considerableoblique shock angle increasewith the rf dischargeturnedon, that is, shockweakening. With the rf discharge on, the shock angle increased from its baseline value of ® D 99 deg to ® 0 D 113 deg, which corresponds to an apparent Mach number reduction from M D 2:06 to 1.88.…”

Section: Introductionmentioning

confidence: 87%

“…17 At M D 2, run durations of at least a few minutes are attained. 18 This is not an arc-heated tunnel. Although the electrical power into the discharges can be rather high, up to 500-W dc and 300-W rf in pure N 2 , up to about 90% of the input power goes into the vibrational and electronic energy modes of nitrogen.…”

Section: Experimental Facilitymentioning

confidence: 99%

“…17 and 18. Brie y, the supersonic ow of nonequilibrium plasma in the wind tunnel is produced by an aerodynamicallystabilizeddiffuse dc glow discharge 17 sustained in the tunnel plenum and by a transverse rf discharge 18 sustained in the supersonic test section. Both discharges can be sustained at quite high plenum and test section pressures, up to P 0 D 2 3 atm and P test D 0:1 atm, respectively, in nitrogen and air.…”

Section: Experimental Facilitymentioning

confidence: 99%

“…17;18 In this experiment, an oblique shock attached to a wedge located in a supersonic ow of a cold, nonequilibrium N 2 -He plasma was monitored using high-pressure plasma ow visualization. The plasma was produced by an aerodynamically stabilized diffuse dc glow discharge 17 sustained in the tunnel plenum and by a transverse rf discharge 18 sustained in the supersonic test section. The advantage of this experiment is that a stationary shock is observed in a steady-state plasma ow with well-characterized parameters.…”

Section: Introductionmentioning

confidence: 99%

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Nonequilibrium Radio Frequency Discharge Plasma Effect on Conical Shock Wave: M = 2.5 Flow

et al. 2003

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An experimental study of shock modi cation in an M = 2:5 supersonic ow of nonequilibrium plasma over a cone is discussed. The experiments are conducted in a nonequilibrium plasma supersonic wind tunnel. Recent experiments at the Ohio State University using a supersonic plasma ow over a quasi-two-dimensional wedge showed that an oblique shock can be considerably weakened by a transverse rf discharge plasma. The previously observed shock weakening, however, has been found consistent with a temperature rise in the boundary layers heated by the discharge. In the present study, the boundary-layereffects on the shock wave are reduced by placing an entire cone model into a supersonic inviscid core ow. The electron density in the supersonic plasma ow in the test section is measured using microwave attenuation. The ionization fraction in the discharge is in the same range as in the previous plasma shock experiments, up to n e /N = (1.2-3.0) £ £ 10 ¡7 . The results do not show any detectable shock weakening by the plasma. This strongly suggests that the previously observed shock weakening and dispersion in nonequilibrium plasmas are entirely due to thermal effects.

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Section: Resultsmentioning

confidence: 91%

Section: Introductionmentioning

confidence: 87%

Section: Experimental Facilitymentioning

confidence: 99%

Section: Experimental Facilitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Nonequilibrium Radio Frequency Discharge Plasma Effect on Conical Shock Wave: M = 2.5 Flow

et al. 2003

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Design exploration on the drag reduction and thermal protection over a blunted waverider with multiple opposing jets

Chen

Liu

Huang

et al. 2022

Aerospace Science and Technology

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Development and use of localized arc filament plasma actuators for high-speed flow control

Utkin

Keshav

Kim

et al. 2007

J. Phys. D: Appl. Phys.

194

115

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The paper discusses recent results on the development of localized arc filament plasma actuators and their use in controlling high-speed and high Reynolds number jet flows. Multiple plasma actuators (up to 8) are controlled using a custom-built 8-channel high-voltage pulsed plasma generator. The plasma generator independently controls pulse repetition rate (0-200 kHz), duty cycle and phase for each individual actuator. Current and voltage measurements demonstrated the power consumption of each actuator to be quite low (20 W at 20% duty cycle). Emission spectroscopy temperature measurements in the pulsed arc filament showed rapid temperature increase over the first 10-20 µs of arc operation, from below 1000 • C to up to about 2000 • C. At longer discharge pulse durations, 20-100 µs, the plasma temperature levels off at approximately 2000 • C. Modelling calculations using an unsteady, quasi-one-dimensional arc filament model showed that rapid localized heating in the arc filament on a microsecond time scale generates strong compression waves. The results of the calculations also suggest that flow forcing is most efficient at low actuator duty cycles, with short heating periods and sufficiently long delays between the pulses to allow for convective cooling of high-temperature filaments. The model predictions are consistent with laser sheet scattering flow visualization results and particle imaging velocimetry measurements. These measurements show large-scale coherent structure formation and considerable mixing enhancement in an ideally expanded Mach 1.3 jet forced by eight repetitively pulsed plasma actuators. The effects of forcing are most significant near the jet preferred mode frequency (ν = 5 kHz). The results also show a substantial reduction in the jet potential core length and a significant increase in the jet Mach number decay rate beyond the end of potential core, especially at low actuator duty cycles.

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Shock wave control by nonequilibrium plasmas in cold supersonic gas flows

Cited by 16 publications

References 0 publications

Nonequilibrium Radio Frequency Discharge Plasma Effect on Conical Shock Wave: M = 2.5 Flow

Nonequilibrium Radio Frequency Discharge Plasma Effect on Conical Shock Wave: M = 2.5 Flow

Design exploration on the drag reduction and thermal protection over a blunted waverider with multiple opposing jets

Development and use of localized arc filament plasma actuators for high-speed flow control

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