implications for plasma flow control and plasma assisted … · 2019-12-12 · energy conversion in...
TRANSCRIPT
![Page 1: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/1.jpg)
Energy conversion in transient molecular plasmas:
Implications for plasma flow control and plasma assisted combustion
Igor Adamovich
Department of Mechanical and Aerospace Engineering
Ohio State University
Plenary lecture, 13th International Conference on Flow Dynamics October 10-12, 2016, Sendai, Japan
![Page 2: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/2.jpg)
Faculty: Igor Adamovich, Walter Lempert, and J. William Rich
Research backgrounds of students and post-docs: Mechanical Engineering, Aerospace Engineering, Electrical Engineering, Chemical Physics, Physical Chemistry, Physics
OSU NETLab
![Page 3: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/3.jpg)
Outline
I. Motivation: critical importance of energy transfer processes in nonequilibrium, high-pressure molecular plasmas
II. Electric field: discharge energy loading and partition
III. Electron density and electron temperature: discharge energy loading and partition
IV. Dynamics of temperature rise: “rapid” heating and “slow” heating
V. Air and fuel-air plasma chemistry: kinetics of plasma assisted combustion
VI. Air plasma kinetics and plasma flow control
VII.Summary and future outlook
![Page 4: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/4.jpg)
I. Motivation
![Page 5: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/5.jpg)
Energy Partition in Air Plasma vs. Electric Field
Energy fraction
Reduced electric field
(4) N2 vibrational excitation: Quasi-steady-state discharges,
low E/N
(1) O2 vibrational excitation: Non-self-sustained discharges,
very low E/N (5,6) electronic excitation,
dissociation, (7) ionization: Pulsed discharges, high E/N
Yu. Raizer, Gas Discharge Physics, Springer, 1991
• Reduced electric field, E/N, controls input energy partition in the discharge
• Rates of electron impact processes: strongly (exponentially) dependent on E/N
![Page 6: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/6.jpg)
Energy conversion in molecular plasmas: here is what we know
• Energy is coupled to electrons and ions by applied electric field
• Electric field in the plasma: controlled by electron and ion transport, and by surface charge accumulation
• Energy partition (vibrational and electronic excitation, dissociation, ionization): controlled by electron density and electric field (or electron temperature)
• Temperature rise in discharge afterglow: controlled by quenching of excited electronic states, vibrational relaxation
• Plasma chemical reactions, rates of radical species generation: controlled by populations of excited electronic states, e.g. N2*, excited vibrational states, e.g. N2(v)
• Time-resolved measurements of 𝑬𝑬, ne , Te , N2*, N2(v), and radical species (O, H,
OH, NO, CH, HO2, CH2O): stable, reproducible, high-pressure ns pulse discharges
• Objective: quantitative insight into energy conversion mechanisms critical for plasma-assisted combustion and plasma flow control
![Page 7: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/7.jpg)
II. Electric field in transient plasmas: insight into discharge energy loading and partition
Diagnostics: CARS-like 4-wave mixing
![Page 8: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/8.jpg)
2-D Ns Pulse Discharge in Atmospheric Air
• Discharge sustained between a high-voltage electrode (razor blade) and grounded copper foil, covered with quartz plate 120 μm thick
• Discharge gap 600 μm
• Simple two-dimensional geometry, diffuse plasma
• Peak voltage 7.5 kV, peak current 7 A, coupled energy 2 mJ
• Two current peaks of opposite polarity: “forward” and “reverse” breakdowns
• Time-resolved electric field measured at several locations in the plane of symmetry
• Electric field distribution along the surface is also measured
-100 -50 0 50 100 150 200 250-7.5
-5.0
-2.5
0.0
2.5
Time [ns]
-7.5
-5.0
-2.5
0.0
2.5
0
1
2
3 Voltage [kV] Current [A] Coupled energy [mJ]
![Page 9: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/9.jpg)
“Curtain Plasma” Images, Negative Polarity Pulse
• Front view: near-diffuse plasma “curtain” • Diffuse surface ionization wave detected, straight ionization front • Wave speed ~ 0.03 mm/ns • Surface plasma layer thickness ~150 μm
Front view, 100 ns gate
Side view, 2 ns gate
Top view, 2 ns gate
Laser beam locations
![Page 10: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/10.jpg)
-200 -100 0 100 200 300 400-6
-4
-2
0
2
4
6
8
10 Voltage Current Absolute field value Assumed field value
Time [ns]
-U [k
V], I
[A]
-30
-20
-10
0
10
20
30
40
50
Elec
tric
field
[kV/
cm]
Time-resolved and Spatially-Resolved Electric Field Measurements
• Initial field offset: charge accumulation on dielectric surface from previous pulse
• Field follows applied voltage rise, increases until “forward breakdown”
• After breakdown, field reduced due to charge accumulation on dielectric surface
• Field is reversed after applied voltage starts decreasing
• After discharge pulse, field decays over several μs: surface charge neutralization by charges from plasma
• Field distribution measured at the moment when field reversal occurs near HV electrode (t=70 ns)
• “Snapshot” electric field distribution across the surface ionization wave front
Laser beam locations
Forward breakdown
Reverse breakdown 100 μm from HV electrode
0 2 4 6 80
10
20
30
40
Elec
tric
field
[kV/
cm]Distance from axis [mm]
t= 70ns
150 μm from surface
![Page 11: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/11.jpg)
III. Electron density and electron temperature in transient plasmas:
insight into discharge energy loading and partition
Diagnostics: Thomson scattering
![Page 12: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/12.jpg)
• Electron density: area under Thomson scattering spectrum
• Electron temperature: spectral linewidth
• Raman scattering rotational transitions in N2 used for absolute calibration
• Gaussian Thomson scattering lineshape: Maxwellian EEDF
Filtered Thomson Scattering: ne , Te, and EEDF inference
0.0E+001.0E+042.0E+043.0E+044.0E+045.0E+046.0E+047.0E+048.0E+04
525 530 535 540Wavelength (nm)
Gaussian Fit
Rayleigh scattering blocked
528 532 5360
10000
20000
30000
40000
50000
60000
Inte
nsity
[a.u
.]
Wavelength [nm]
N2 Raman scattering
10 mm
He, 200 Torr
![Page 13: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/13.jpg)
Thomson Scattering Spectra Sphere-to-sphere ns pulse discharge in H2-He and O2-He
10% O2-He, P=100 torr, t=100 ns ne= 1.7·1013 cm-3, Te= 1.6 eV, T=350 K
5% H2-He, P=100 torr, t=100 ns ne = 1.5∙1014 cm-3, Te = 2.0 eV
![Page 14: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/14.jpg)
Electron Density and Electron Temperature Sphere-to-sphere ns pulse discharge in O2-He
• ne = 1013 - 3∙1014 cm-3 , Te = 0.3 – 5.5 eV (0-10% O2)
• “Double maxima” in ne, Te : two discharge pulses ≈400 ns apart
• Electron temperature in the afterglow Te ≈ 0.3 eV Superelastic collisions prevent electron cooling
• Modeling predictions in good agreement with data
0 400 800 1200 1600 2000 24000
1
2
3
4
n e [10
14 c
m-3]
Time [ns]
0 50 100 150 2000
1
2
3
4
n e [10
14 c
m-3]
Time [ns]
0% O2
1% O2
2% O2
5% O2
10% O2
0 400 800 1200 1600 20000
2
4
6
T e [eV
]
Time [ns]
0 50 100 150 2000
2
4
6
T e [eV
]
Time [ns]
0% O2
1% O2
2% O2
5% O2
10% O2
0 200 400 600 8000
1
2
3
4 Experimental ne
Predicted ne
Experimental Te
Predicted Te
Time [ns]
n e [10
14 c
m-3]
0
1
2
3
4
T e [eV
]
10% O2-He
![Page 15: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/15.jpg)
IV. Dynamics of temperature rise in transient plasmas: “rapid” heating and “slow” heating
Diagnostics: vibrational and pure rotational ps CARS
![Page 16: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/16.jpg)
2320 2325 23300
50
100
150
200
Raman Shift [cm-1]
Sqrt(
Int.)
[au]
DataTfit=300K
Sphere-to-sphere ns pulse discharge in air, P=100 Torr Discharge pulse waveforms and CARS spectra
N2(v=0) band (without plasma) N2(v=0-9) bands during and after discharge pulse
10 mm
2 mm Pulse energy coupled to plasma ~ 0.5 eV
![Page 17: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/17.jpg)
Temperature rise in ns pulse discharge and afterglow: air vs. nitrogen
• Compression waves formed by “rapid” heating, on sub-acoustic time scale, τacoustic ~ r / a ~ 2 μs
• Strong effect on high-speed flows
t= 1-10 μs (frames are 1 μs apart)
Air, P=100 Torr
![Page 18: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/18.jpg)
• Strong vibrational excitation in the discharge, N2(v=0-8)
• Tv(N2) rise in early afterglow: V-V exchange, N2(v) + N2(v=0) → N2(v-1) + N2(v=1)
• Tv(N2) decay in late afterglow: V-T relaxation, N2(v) + O → N2(v-1) + O , radial diffusion
• “Rapid” heating: quenching of N2 electronic states, N2(C,B,A,a) + O2 → N2(X) + O + O
• “Slow” heating: V-T relaxation, N2(X,v) + O → N2(X,v-1) + O
• “Rapid” heating: pressure overshoot on centerline, compression waves detected in experiments
• NO formation: dominated by reactions of N2 electronic states, N2* + O → NO + N, also in good
agreement with [NO], [N] measurements
Comparison with modeling predictions in air: vibrational kinetics and temperature rise
![Page 19: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/19.jpg)
Rapid N2 relaxation and temperature rise. Mechanism of accelerated heating:
• V-V energy exchange between N2 and CO2(ν3) mode: N2(v=1) + CO2(000) ↔ N2(v=0) + CO2(001)
• CO2 energy re-distribution among vibrational modes: CO2(001) + M ↔ CO2(100,020,010) + M
• V-T relaxation of bending mode: CO2(010) + M → CO2(100) + M
• Strong effect on nonequilibrium compressible flows
Adding CO2 (rapid V-T relaxer) to air: accelerating energy thermalization rate
![Page 20: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/20.jpg)
V. Fuel-air chemistry in transient plasmas: kinetics of plasma assisted combustion
Diagnostics: Rayleigh scattering, LIF, CARS
![Page 21: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/21.jpg)
Hot central region: OH production dominated by chain branching H + O2 → OH + O ; O + H2 → OH + H
Colder peripheral region: OH accumulation in HO2 reactions
radial diffusion of H atoms; H + O2 + M → HO2 ; H + HO2 → OH + OH
Plasma chemical reactions and transport: ns pulse discharge in H2 - O2 - Ar, P=40 torr
![Page 22: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/22.jpg)
[OH] kinetics in preheated fuel-air mixtures after ns pulse discharge burst
Comparison with modeling predictions: plasma assisted combustion kinetic mechanism validation
“Near 0-D” diffuse plasma, a burst of 50-100 pulses used to couple sufficient energy
H2 – air, ϕ=0.3 T0=500 K, P=100 torr
C2H4 – air, ϕ=0.3 T0=500 K, P=100 torr
Pulse #10 Pulse #100
End View
![Page 23: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/23.jpg)
Plasma chemical reactions reduce ignition temperature in H2-air
• ϕ=0.4, 120-pulse burst, T0=500 K, P=80-90 torr
• Model predictions: good agreement with time-resolved temperature measurements
• Ignition temperature with plasma, Ti ≈ 700 K, lower than autoignition temperature, Ta ≈ 900 K
![Page 24: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/24.jpg)
VI. Air plasma kinetics and plasma flow control
![Page 25: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/25.jpg)
• Every nanosecond discharge pulse produces a robust spanwise vortex
• Enhanced mixing with free stream → boundary layer reattachment
• Same effect detected up to u=96 m/sec (M=0.28, Rex~1.5 ∙106)
• Consistently outperform AC DBD actuators
45 m/sec
Ns DBD plasma actuators: subsonic flow boundary layer reattachment
![Page 26: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/26.jpg)
Localized Arc Plasma Flow Actuators (LAPFA): Exciting instabilities in transonic and supersonic flows (M=0.9-2.0)
3
4
5
PC
Nozzle extension
DC power supply
DC power supply
1 2
6
8
7
Resistors (15 kOhm)
Optical Isolation
HV switches Resistors
(15 kOhm)
8 Channel
digital-to-analog card
• BN nozzle extensions, tungsten wire electrodes
• Circular nozzle, 1 inch diameter recently
• Multiple channels controlled by fast HV switches
• Independent control of frequency, phase, and duty cycle → excitation of different instability modes
![Page 27: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/27.jpg)
Axisymmetric mode
First helical mode
Flapping mode
LAPFA: Formation of coherent structures in a M=0.9 circular jet
• High amplitude perturbations (localized heating in arc filaments)
• Every discharge pulse results in vortex formation
• Flow responds to forcing near jet column instability frequency
![Page 28: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/28.jpg)
• Plenum: overlapped ns pulse / DC sustainer discharge for vibrational loading of N2
• P0 = 300 torr, TV=2000, T=500 K, 2-D nozzle, top wall contoured, bottom wall plane
• Condition at nozzle exit : M = 2.5, Pexit = 15 torr
• Subsonic flow below expansion corner: injection of N2 or CO2
• Optical access for schlieren, CARS, and NO PLIF in subsonic and supersonic flows
Control of supersonic mixing / shear layer by accelerated relaxation of vibrational energy
DC sustainer electrodes
Flow into the page
Injection flow: N2, CO2, or 20% CO2 – N2
Pulser electrodes
DC electrodes
Main flow: N2
Optical access window
Static pressure port
θ
Expansion fan
Lip shock
Shear layer
To vacuum
![Page 29: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/29.jpg)
• Time delay between frames 5 ms, t = 0-80 ms
• Ns pulse / DC discharge (2.3 kW) is turned on at t = 10-45 ms, to excite main N2 flow
• No perturbation of shear layer detected in N2 / N2 flow
• In N2 / CO2 flow, shear layer expansion angle decreases, approaching θ=0˚
• No change observed if main N2 flow is not excited
Effect of vibrational relaxation of shear layer: N2 / N2 (left) vs. N2 / CO2 (right)
CO2
N2
N2
N2
CO2 “bleeding” through backstep N2 “bleeding” through backstep
![Page 30: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/30.jpg)
• Top flow: vibrationally excited N2, TV=1900 K, estimated Trot=240 K
• Bottom flow: CO2 bleeding through backstep, static pressure 7 torr
• CO2 bleeding reduces TV(N2), increases Ttrans/rot and static pressure
• Consistent with time-resolved measurements in ns pulse discharge in quiescent N2-CO2
• Static pressure increase pushes up shear / mixing layer
N2 Vibrational Temperature Distribution in Shear Layer
![Page 31: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/31.jpg)
Summary: air plasma kinetics
• Growing body of time-resolved, spatially-resolved data characterizing transient, high-pressure air and fuel-air plasmas
• Measurements of electric field, electron density, and electron temperature necessary for insight into discharge energy coupling and partition
• Measurements of temperature, N2(v) populations, and excited electronic states of N2
* necessary for insight into temperature dynamics
• Measurements of N2* and key radicals (O, H, OH, and NO) critical for
quantifying their effect on fuel-air plasma chemistry
• Comparing measurement results with kinetic modeling predictions provides confidence in the models, assesses their predictive capability
![Page 32: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/32.jpg)
• Surface and volumetric ns pulse discharges: energy thermalization on sub-acoustic time scale, high-amplitude compression wave generation
• Mechanism of energy thermalization (“rapid heating” and “slow heating”) is well understood
• NS-DBD surface plasma actuators: large-scale coherent flow structures; significant flow control authority in subsonic flows (up to M = 0.3) at low actuator powers; scalable to large dimensions (~1 m)
• LAFPA actuators: large-scale coherent structures; excitation of flow instability modes; significant control authority in transonic and supersonic flows (M = 0.9-2.0) at low actuator powers; scalable to large phased arrays
• Flow control by vibrational relaxation: injection of “rapid relaxer” species into nonequilibrium flow at desired location; temperature and pressure rise due to accelerated relaxation; strong effect in supersonic shear layer
Summary: nonequilibrium plasma flow control
![Page 33: Implications for plasma flow control and plasma assisted … · 2019-12-12 · Energy conversion in transient molecular plasmas: Implications for plasma flow control and plasma assisted](https://reader034.vdocument.in/reader034/viewer/2022050400/5f7dd057a2e16e0bbf76b461/html5/thumbnails/33.jpg)
AFOSR MURI “Fundamental Mechanisms, Predictive Modeling, and Novel Aerospace Applications of Plasma Assisted Combustion” AFOSR BRI “Nonequilibrium Molecular Energy Coupling and Conversion Mechanisms for Efficient Control of High-Speed Flow Fields” DOE PSAAP-2 Center “Exascale Simulation of Plasma-Coupled Combustion” (under U. Illinois at Urbana-Champaign prime) US DOE Plasma Science Center “Predictive Control of Plasma Kinetics: Multi-Phase and Bounded Systems” NSF “Fundamental Studies of Accelerated Low Temperature Combustion Kinetics by Nonequilibrium Plasmas”
Acknowledgments