sergey b leonov and dmitry a yarantsev- plasma-induced ignition and plasma-assisted combustion in...

8/3/2019 Sergey B Leonov and Dmitry A Yarantsev- Plasma-induced ignition and plasma-assisted combustion in high-speed fl

1/7

INSTITUTE OF PHYSICS PUBLISHING PLASMA SOURCES SCIENCE AND TECHNOLOGY

Plasma Sources Sci. Technol. 16 (2007) 132138 doi:10.1088/0963-0252/16/1/018

Plasma-induced ignition and

plasma-assisted combustion in high-speedflow

Sergey B Leonov and Dmitry A Yarantsev

Institute of High Temperatures RAS (IVTAN), Izhorskaya str., 13/19, Moscow, 125412,

Russia

E-mail: [email protected] and [email protected]

Received 17 March 2006, in final form 10 July 2006Published 20 December 2006Online at stacks.iop.org/PSST/16/132

AbstractThe suitability of the electrical discharge technique for application inplasma-induced ignition and plasma-assisted combustion in high-speed flowis reviewed. Nonequilibrium, unsteady and nonuniform modes are underanalysis to demonstrate the advantage of such a technique over heating. Areduction in the required power deposition is possible due to unsteadyoperation and non-homogeneous spatial distribution. Mixing intensificationin non-premixed flow could be achieved by nonuniform electricaldischarges. The scheme of fuel ignition behind the wallstep and in the cavityis under consideration. Experimental results on multi-electrode dischargemaintenance in the separation zone of supersonic flow are presented. The

model test on hydrogen and ethylene ignition is demonstrated at direct fuelinjection. An energetic threshold of fuel ignition under separation and in theshear layer is measured under the experimental conditions.

(Some figures in this article are in colour only in the electronic version)

1. Introduction. Plasma-assisted combustionapproach

Analysis of supersonic combustor performance shows that

several principal problems related to supersonic combustion

and flame stabilization are to be solved for the practical

implementation of such a technology, especially in the case ofhydrocarbon fuels. The plasma-based methods of combustion

management under scramjet conditions are now considered

as one of the most promising technologies in this field

[17]. Electrical discharge properties strongly depend on the

conditions of excitation, flow parameters and characteristics

of the supplying electromagnetic power. The analysis of

applicable discharge types can be done from the viewpoint

of the plasma-assisted combustion concept, which consists

of three important items: ignition and combustion chemistry

enhancement due to heating and active particle generation (1),

airfuel mixing intensification in flow (2) and flow structure

management for flame front stabilization (3). At least four

This paper was presented at the Second International Symposiumon Nonequilibrium Processes, Combustion, and Atmospheric Phenomena(Dagomys, Sochi, Russia, 37 October 2005).

mechanisms of theplasma effect on flow structure, ignition and

combustion processes might be listed: fast local ohmic heatingof the medium (1), nonequilibrium excitation and dissociationof air and fuel molecules due to electron collisions and UV

radiation (2), momentum transfer in electric and magneticfields (3) and shocks/instabilities generation (4). The electrical

discharges, which are generated under the conditions of high-speed flow, possess several specific properties. These featuresmight be important for the discharge applications for flow

parameter and structure control and combustion enforcementunder unfavourable conditions.

Local heating of the medium leads to intensification ofthe chemical reactions in these areas. A controlled energydeposition affects the flow structure, including generation of

zones with artificial separation at a sufficiently high level ofinput power [8, 9]. It is a method of flow structure steering.

It allows increasing local residence time to provide a zone oflocal combustion. The airfuel mixing is intensified as well.

Active radical generation is due to molecule dissociation

and excitation by electrons in the electric field, radiationand more complex processes. The presence of chemical

radicals (for example, O, OH, H, NOx ) or vibrationally excited

0963-0252/07/010132+07$30.00 2007 IOP Publishing Ltd Printed in the UK 132
mailto:%[email protected]:%[email protected]://stacks.iop.org/ps/16/132mailto:%[email protected]:%[email protected]://dx.doi.org/10.1088/0963-0252/16/1/018


2/7

Plasma-induced ignition and plasma-assisted combustion

molecules can effectively improve ignition conditions but

the problem is at the level of the required electric power.

If the chain chemical reactions are realized, the production

of even a small amount of active particles can lead to a

large (synergetic) benefit in total reaction rates, as well as

in diminishing of the required power input. Gas dischargepotentials for the gas non-equilibrium excitation are widely

discussed as an advanced technology. Generally speaking, any

type of excitation (dissociation, ionization, electron excitation

or vibrational excitation) affects the reaction rates positively.

Two main processes can result in excitation of an atom or

molecule: electron impact and photo-excitation. The first one

is effective at a high magnitude of the reduced electric field,

E/N. The second one is effective at superheating of the

dischargechannel (highintensityof thethermal radiation). The

first effect occurs mostly in high-frequency and short-pulsed

discharges or at intensive cooling of the discharge area [9].

The second one could be realized at high values of specific

energy input (several eV per atom/molecule) [10].Shock wave generation promotes the mixing processes

in a heterogeneous medium and initiates chemical reactions

due to heating in the shock front zone. Also there can exist

various typesof plasmainstabilities, for example, longitudinal-

transverse instability of plasma filament, which has been

revealed recently [9]. It leads to intensive small scale mixing

inflow. It should be noted that in general there are no methods

to separate the specific mechanisms of the plasma effect

because of interference between them.

Typical conditionsfordischargemaintenance in aerospace

science: pressure P = 0.11 bar, velocity of the flow V =

1001000 m s1. Characteristic temperatureof gas varies from

T = 200 K (ambient conditions) to T 2 kK for the com-bustion chamber. As a rule, at such conditions the plasma

of electric discharges appears in the filamentary form due to

instabilities mostly associatedwiththe mechanism of electrical

field enhancement in the vicinity of the heated plasmachannel.

At present, there are no reliable universal rules for the appear-

ance of any electric discharges at high temperature. Under

high pressure and high-speed flow most types of discharge

are nonuniform and nonequilibrium. The high-pressure glow

discharge [11, 12] is a rather homogeneous one, and the high-

current longitudinal arc produces the equilibrium plasma. The

strong non-uniformity of the plasma inflow renders a chance

for a significant decrease in the required electrical power for a

predefined effect. This idea is in local multi-points influencewith sequential expansion of flame fronts.

The complete management of the combustion process

under any conditions requires a large level of additional

energy deposition (in a range of flow enthalpy) that is beyond

practical interest. The idea is not related to the strong effect

of energy release but to the gentle control of the chemical

reaction rate and local multi-ignition. The second direction

is to give the gear to force the combustor to work under

off-design conditions. It may be a temporal mode when

the level of required electric energy is not vitally important.

Unfortunately, specific information available now is not quite

sufficient for the proper choice of the discharge type. Our

understanding is that there is no versatile solution to the designand method of application of plasma for combustion. Each

specific situation has to be considered separately. But it seems

(a)

(b)

Figure 1. Basic scheme of electrode arrangement.

clear that thenonequilibrium andnonuniform operationmodes

are preferable. Our understanding also is that plasma has to

be generated in situ just in the location of the fueloxidizer

interaction but not by an external device.

2. Experimental facility pwt-50

A deeply renovated experimental facility PWT-50 is used for

testing of the hydrogen ignition by the electrical discharge

behind the wallstep and in a cavity of the high-speed duct.

The following gasdynamic parameters of the test are provided

by PWT-50: Mach number in duct M = 1.92; initial static

pressure Pst = 0.120.25 bar; stagnation temperature of theair

T0 = 300K; test section dimensions 7260 mm; steady-stage

operation time 0.30.5 s.

Themeasuring systemincludesthe sensors of pressure and

temperature of the initial flow, pressure transducers (pressure

distribution measurements), spectroscopic system, optical

sensors, Schlieren system, fast video cameras, electrical

parameter sensors, IR camera and IR spectroscopy. Thedata acquisition system includes PC-based individual devices

for pressure distribution records, video camera control,

spectroscopic and operation parameter records.

The plasma generator was designed and constructed for

applications in high-speed flow on the basis of experimental

results obtained during a previous study of quasi-dc, pulse

periodic and modulated RF discharges [810, 13]. The

electrode configuration (line near the edge of the wallstep and

line at the bottom of the separation zone) was proposed and

described in [16]. Figure 1 presents the scheme of electrode

arrangement and corresponding photo of the real device.

It consists of two insertions made of refractory insulating

material. The first insertion is arranged on the edge of thebackward wall-step, andthe secondone is located at thebottom

of the separation zone. Both of them are flush mounted as

133


3/7

S B Leonov and D A Yarantsev

well as the electrodes themselves. Each insertion has the

same construction: nine electrodes in two rows arranged in

an interlacing manner (4 + 5).

In thefirstinsertionthe first row isapplied forthe discharge

primary initiation, whereas the second row contains working

anodes. The first line of electrodes in the second insertion isreserved for extra control of the discharge and measurements

of the cathode voltage drop; the second line is operated as

working cathodes. Such electrode arrangement allows for

quite flexible operation. The discharge operates with the

following parameters: type of dischargefilamentary quasi-

continuous; operation time of dischargetpl = 50500ms;

current through eachelectrodeIpl1 = 14A; mean electrical

input powerWpl = 110 kW that is equivalent to mean gas

temperature elevation less than Tav = 20K.

The fuel injectors are installed directly on the bottom wall

of the test section as shown in figure 1. They contain a fuel

capacitor at 56 bar of pressure and fast pulse valve with EM

control. Thefuel dose and duration of the injection depends onthe EM pulse duration and the repetition rate. Minimal dose

at the single pulse is about 1mg. Maximal mass flow rate is

about 5g s1.

3. Discharge appearance near the backwardwallstep and cavity (experiment and CFD)

Numerous experiments were done at different conditions:

subsonic and supersonic flow; wallstep, long cavity (l/d =

6.5) and short cavity (l/d = 3.3); different pressure; current

from 5 to 20 A; both polarities, etc. Here the data for the

wallstep in supersonic mode are shown for the typical electric

current.

3.1. Plasma filament dynamics in high-speed flow

The discharge dynamics in flow behind the wallstep was

explored using a high-speed digital CMOS camera with a

typical frame rate of2000 fpsat 1280250pixelsand exposure

down to 30 s. As a sample in figure 2 two selected frames

are presented for operation in supersonic mode in the cavity

and behind the wallstep correspondingly.

It is seen that in the first case the discharge cord looks

unstable. A full frame sequence shows a fast movement of

them in the separation zone. The S-type of the plasma cord

shape reflects the flow velocity distribution under separation.

An intensification of flow circulation due to energy release isproved also by simulation (see below). In contrast with that

the shape of the discharge cords is very stable in the supersonic

mode with the backward wallstep. Cord location repeats the

edge of the separation zone (in this case the zone has a minimal

size among others).

3.2. Voltagecurrent measurements

Measurements of voltagecurrent characteristics were made

for the 5-cords plasma generator. Figure 3 presents

oscillograms of the discharge voltage, current and recalculated

power for two cases: discharge in the cavity and behind the

backward wallstep.The input power weakly depends on static pressure under

the explored conditions (M = 1.9). The greatest effect can

(a)

(b)

Figure 2. Discharge appearance in the supersonic mode at thecavity and behind the backward wallstep.

(a)

(b)

Figure 3. Typical oscillograms of the discharge operation insupersonic operation mode, M0 = 1.9, short cavity (a) and wallstep(b). Average power is calculated.

be obtained by electric current regulation. In the case of

supersonic flow over the cavity (short cavity and long cavityboth) electric parameter behaviour is very similar to in the

subsonic mode. It is characterized by a significant level of

134


4/7


voltage vibrations. This fact reflects the close aerodynamic

situations when the plasma filaments migrate in the separation

zone with wide variation of their length that is a result of

gas movement (see above). In the case of discharge in the

cavity the characteristic frequency of the voltage oscillations

was about f = 12 kHz, which corresponds to the internalflow velocity in a range V = 1040ms1.

In the case of the supersonic mode in the duct with the

backward wallstep the amplitude of such vibrations was much

less which is seen in the following graphs. The appropriate

frequency is higher. The plasma cord position is quite stable

in theshear layer andthefilaments areshorter themselves. The

fields magnitude is significantly higher than in the case of the

subsonic flow. Dueto field elevation (E/ n 51016 V cm2)

the electron temperature has to be increased from Te = 0.8 ev

to Te = 1.5 evapproximately. Plasma-chemicalreactions have

to be activated as well.

3.3. Measurements of plasma temperature

Optical spectroscopy is used to measure the plasma

temperature [17, 18]. Measurements were carried out at three

different values of ballast resistance (1+0 .2 kOhm, 1+1 kOhm

and1+2 kOhm)in theseparation zone of theduct. Temperature

was measured by fitting of the experimental and the calculated

spectra of the N2 second positive system (00, 337.1 nm) and

of the violet system of CN (388.9 nm).

By the analysis of N2 spectra the rotational temperature

was found to be the same for different conditions; its value

is Trot = 3.0 0.2 kK. Temperature measurements carried

out by the CN spectrum give the following results: Tvib =

7.50.5kK; Trot = 70.5 kK.Suchhigh values areexplained

by the fact that we measure temperature of the exited state of

the CN molecules whereas rotational temperature measured

by the N2 spectrum is equal to the temperature of the N2ground state. It is clear that under conditions of high non-

uniformity of the discharge structure the measured magnitude

of temperature is between the maximal and average values. As

a result the different molecular bands can give different formal

temperatures. The averaged gas temperature in the cavity is

evaluated at Tcav = 200 K.

3.4. Discharge effect on flow structure near the wall step and

cavity

Two methods were utilized mainly to study the dischargeeffect on flow structure behind the wallstep and in the

cavity: pressure measurements and Schlieren visualization.

A 16-channel pressure recorder was used in the tests. The

sensor arrangement is shown near an appropriate picture.

Typical data are presented in figure 4.

Summarizing the discharge effect on pressure distribution

in the cavity and behind the wallstep it should be considered

that, as a rule, the pressure rises noticeably just near the

discharge zone and its distribution occurs more smoothly in

the cavity as a whole.

3.5. Schlieren visualization

The Schlieren system was adjusted to work in the pulse mode

of the flash-lamp with frame frequency f = 100 Hz. The

Figure 4. M= 1.9, discharge is switched on before flow start andswitched off in t= 0.17s.

(a)

(b)

Figure 5. Schlieren photos of the discharge effect on flow structure.Supersonic mode, wallstep.

images are presented as a pair (discharge off/on) for the

operation modes when the power deposition is in the range

Wav = 57kW, staticpressure in thesupersonic M1.9 mode

Pst = 120180 Torr. The exposure time of the photos in

figure 5 was t= 1 s.

As can be easily recognized, the discharge effect on the

flow structure in the cavity and behind the wallstep lies in

an intensive turbulization of gas in the interaction area at asimultaneous slight increase in the separation zone volume.

Numerical modelling of flow in the experimental set-up

was based on the solution of 3D time-dependent Reynolds

averaged NavierStoke equations (URANS-method) with the

utilization of the widely used two-equation SST-model of

turbulence. Calculation of three-dimensional turbulent flow

in the frame of the model of perfect gas (5 components) in the

experimental set-up was executed by modelling a heat supply

causedby the direct current electric discharge. Constant values

of velocity V = 317ms1, total pressure P0 = 105 Pa and

temperature T = 250 K were specified in the initial section of

the calculation domain being the critical section of supersonic

nozzle M = 2. Zero gradients of flow parameters in theoutlet section of the calculation domain were fixed. Non-

slip and adiabatic conditions were specified on the upper,

135


5/7


Figure 6. Isothermal surfaces Tg = 2000K.

lower and lateral walls of the duct as well as on the cavity

walls. Symmetry conditions were used in the median section

of theduct to decrease thecalculation domain which contained

600000 mesh points.

The results of computational analysis were obtained forpower deposition Wpl = 5 kW that is close to the experimental

value. As far as possible, the results of simulations are

compatible with experimental data. The isothermal surfaces

are presented in figure 6 for a sample. The essentially three-

dimensional character of the considered flow is demonstrated

by this. The important issue is a rate of gas exchange between

the main flow and the separation zone. The calculated values

are equal to G0 = 0.0054kgs1 and GQ = 0.0074kgs

1,

respectively, without heat input and with it. The experimental

value on the velocity of gas circulation in the cavity gave a

similar result. On thebasisof these data thefirst approximation

for the required amount of the injected fuel to provide a

stoichiometric gas composition in the cavity can be calculated:GH2 0.15gs1 and GC2H4 0.4 g s

1.

4. Hydrogen ignition under separation in supersonicflow (experiment)

Preliminary results of hydrocarbon fuel ignition behind a

backward wallstep were published in [1,1315]. The results

of the recent tests on hydrogen ignition in the separation

zone of low-temperature supersonic flow are presented in

this section. Several diagnostics were applied: natural

observations, Schlieren photos, spectroscopy, pressure record,

etc. The most reliable way to recognize combustion was a

great pressure growth in the separation zone.Figure 7 presents typical experimental data on the

hydrogen ignition by the discharge in the short cavity. The

first frame shows the discharge just before the fuel injection,

the second frame related to the combustion. The third plot

shows time behaviour of pressure near the zone of interaction:

total pressure P0 downstream of the cavity and normalized

static pressure Ps in the separation zone Ps = Pst1 Pst0 +

Pst0(t = 0), where Pst1 is static pressure in cavity, Pst0 the

static pressure upstream. The data are synchronized with

the discharge current. The temperature of the downstream

(inclined) wall is shown as measured by a thermocouple (it

reflects the trend only). The heating of this wall by the

discharge does notexceed 30 K. Thefourthpicture presents theSchlierenphotosof interaction. An estimationand comparison

with numerical simulations indicate a level of pressure step

(a)

(b)

(c)

(d)

Figure 7. Discharge interaction with injected hydrogen. Photos (a),(b), pressure (c), Schlieren photos (d).

P = 1020 Torr in the cavity in case the oxidizer is provided

by circulating air.

Two modes of discharge-fuel-flow interaction were

observed: fuel ignition and combustion just in a cavity and

fuel combustion in a shear layer of supersonic freestream. In

the case of hydrogen injection both the modes were detected.Under experimental conditions, the ethylene combustion was

detected in the cavity only.

136


6/7


(a)

(b)

Figure 8. Discharge interaction with injected hydrogen behindwallstep. Pressure (a), Schlieren photos (b).

The hydrogen combustion in the cavity takes place if

the power deposition in the discharge W > 1 kW. If the

discharge was turned off, the combustion in the cavity reaches

the unstable mode. Increase in the hydrogen flow rate over the

stoichiometric ratio pushes the combustion above the cavity, if

the power deposition is not less than Wpl = 3 kW. When the

thermal power of combustion grows more than Wfuel = 20kW

a thermal choking of the duct occurred.

It is well known that some widening of the gasdynamic

duct downstream helps to prevent a thermal chocking. Figure8demonstrates the hydrogen combustion in the shear layer of

free stream in a configuration with the backward wallstep

for the hydrogen mass flow rate increased up to GH2 =

4 g s1. The reactions were very intensive without blockage

of the supersonic operation mode. It is seen how the flow

disturbances produced by combustion occupied almost an

entire duct. The discharge switching off destroys this regime

immediately.

It is clear that the flash of radiation does not reflect the

fact of fuel combustion itself. One important feature of the

discharge-fuel interaction is the dramatic growth in radiation

intensity from the volume, especially for hydrocarbon fuel.

Sometimes it exceeds a factor of magnitude 103

. This rise takeplace in continuous spectra and molecular bands CN, C2 and

others. In [14] the effect wasnamed as cyan catastrophe. For

(a)

(b)

Figure 9. Samples of time behaviour of the discharge spectrumunder ethylene (a) and hydrogen (b) injection. Each spectrum has10 ms exposure.

illustration purposes, some results of spectral measurements

are shown in figure 9 for the ethylene and hydrogen injection.

Analysis of the spectral data leads to consideration of the

important role of atomic oxygen generated by the discharge

for the combustion chemistry. Figure 9(b) presents a spectral

sequence when the discharge is operated slightly before the

hydrogen injection. It is seen that theamplitudeof theresonant

spectral line of atomic oxygen grows in the discharge area

and drops at combustion. Generally, this situation should

be analysed in more detail to find the quantitative relations

between radiation intensityandconcentration of excited atoms.

Of interest is thefact that thedischarge switching-off leads

to immediate extinction of the hydrogen flame in a free stream,

but the combustion in the cavity can continue. The power

threshold of hydrogen ignition in the shear layer wasmeasured

by variation of powerdeposition. It is about Wpl = 3 kW under

the conditions of the test.

5. Conclusions

Control of ignition in aircraft jet engines is of crucial

importance for their performance over a wide range of

operation parameters, such as altitude, flight speed and

thrust. Reduction in ignition delay time, flameholding and

flame stability improvement, flame blow-off prevention andextension of fuel flammability limits are some of the key

technicalissues in this field. In this paper theextramechanisms

137


7/7


(plasma technology) aredescribedas promisingcontenders for

the mechanical methods.

A conception of plasma-assisted combustion has been

formulated. Methods for high-speed combustion control

were considered: plasma-induced ignition, plasma-intensified

mixing and flame-holding by plasma generation. The mainphysical mechanisms of the plasma effect are described.

Previously proposed multi-electrode quasi-dc discharge

through theseparation zone wasdeveloped forutilization in the

cavity and wallstep of the supersonic duct. The peculiarities

of the filamentary discharge maintenance in high-speed flow

under separation were explored experimentally. 3D CFD

simulation was performed for getting a deeper insight into

and prediction of critical parameters for the plasma-ignition

experiment.

The results of model experiments on the ignition of non-

premixed air-fuel (hydrogen and ethylene) streams in high-

speed low-temperature flow behind a backward wallstep and

in the cavity are presented. The energetic threshold of thehydrogen ignition in the shear layer was measured at a value

W = 3 kW for the experimental conditions. It is concluded

that the detection of the radiation increase is not a reliable

method of combustion monitoring, if an electric discharge is

maintained.

Experimental and theoretical efforts for a broader range

of parameters are planned for the future.

Acknowledgments

The authors express their gratitude to Dr Valentin Bityurin

for multiple discussions regarding CFD efforts, Mr Konstantin

Savelkin of IVTAN for valuable assistance in experimentalwork, Dr Valery Sermanov of TsAGI for consultation on the

high-speedcombustion techniqueandDr Michail Starodubtsev

for CFD efforts. The results would not be possible without

the excellent work of IVTANs laboratory personnel who

participated in the experimental efforts.

Currently the work is funded by EOARD (ISTC Project

3057p, Dr Campbell Carter technical supervision). Some parts

of this work were supported by Program #20 of the Russian

Academy of Science (co-ordinator Academecian. Gorimir

Cherny).

References[1] Leonov S B, Yarantsev D A, Napartovich A P and

Kochetov I V 2006 Plasma assisted chemistry in high-speedflow Proc. XVI Int. Conf. on Gas Discharges and their

Applications (Xian, China, 1115 September 2006) vol 2,pp 8736

[2] VanWie D, Risha D and Suchomel C 2004 Research issuesresulting from an assessment of technologies for futurehypersonic aerospace systems 42th AIAA AerospaceSciences Meeting and Exhibit (Reno, NV, 58 January2004) AIAA-2004-1357

[3] Jacobsen L, Carter C, Baurie R and Jackson T 2003Plasma-assisted ignition in scramjet 41st AIAA Aerospace

Meeting and Exhibit (Reno, NV, 69 January, 2003)AIAA-2003-0871

[4] Starikovskii A 2004 Plasma supported combustion invitedlecture 30th Int. Symp. on Combustion Proc. Combustion

Institute (Chicago, 2004) (Invited Lecture) p 326

[5] Buriko Yu Ya, Vinogradov V A, Goltsev V F and Waltrup P J2002 Influence of radical concentration and fueldecomposition on ignition of propane/air mixture J. Propul.Power18 104958

[6] Bao A, Lou G, Nishihara M and Adamovich I 2005 On themechanism of ignition of premixed COair and

hydrocarbonair flows by nonequilibrium RF plasma 43rdAIAA Aerospace Meeting and Exhibit (Reno, NV, 1013January 2005) AIAA-2005-1197

[7] Klimov A, Bityurin V, Brovkin V and Leonov S 2000 Plasmagenerators for combustion Workshop on Thermo-chemicalProcesses in Plasma Aerodynamics (Saint Petersburg, May30June 3, 2000) p 74

[8] Leonov S, Bityurin V, Savelkin K and Yarantsev D 2003Progress in investigation for plasma control of duct-drivenflows 41th AIAA Aerospace Meeting and Exhibit (Reno, NV,610 January 2003) AIAA-2003-0699

[9] Leonov S B, Savelkin K V, Yarantsev D A and Gromov VG2005 Aerodynamic effects due to electrical dischargesgenerated inflow Proc. European Conf. for AerospaceSciences (EUCASS) (Moscow, July 2005)

[10] Leonov S B, Yarantsev D A and Isaenkov Yu I 2005 Properties

of filamentary electrical discharge in high-enthalpy flow43rd AIAA Aerospace Sciences Meeting & Exhibit (Reno,

NV, 1013 January 2005 ) AIAA-2005-0159[11] Akishev Yu S, Kochetov I V, Leonov S B and Napartovich A P

2003 Production of chemical radicals by self-sustaineddischarge in air gas flow Proc. 5th Int. Workshop on

Magneto-Plasma Aerodynamics for Aerospace Applications(Moscow, IVTAN, April 2003)

[12] Napartovich A, Kochetov I and Leonov S 2005 Study ofdynamics of air-hydrogen mixture ignition bynon-equilibrium discharge in high-speed flow J. High Temp.43 667 (in Russian)

[13] Leonov S, Bityurin V, Bocharov A, Savelkin K, VanWie Dand Yarantsev D 2002 Hydrocarbon fuel ignition inseparation zone of high speed duct by discharge plasmaProc. 4th Workshop PA and MHD in Aerospace

Applications (Moscow, April, 2002, IVTAN) paper no. 32,pp 20010

[14] Leonov S, Bityurin V, Savelkin K and Yarantsev D 2003Plasma-induced ignition and plasma-assisted combustionof fuel in high speed flow Proc. 5th Workshop PA and MHDin Aerospace Applications (Moscow, IVTAN, 710 April2003)

[15] Leonov S B, Bityurin V A, Yarantsev D A, Napartovich A Pand Kochetov I V 2005 Plasma-assisted ignition and mixingin high-speed flow Proc. 8th Int. Symp. on Fluid Control,

Measurement and Visualization (Chengdu, China, 1923August 2005)

[16] Leonov S, Bityurin V, Bocharov A, Gubanov E,Kolesnichenko Yu, Savelkin K, Yuriev A andSavischenko N 2001 Discharge plasma influence on flow

characteristics near wall step in a high-speed duct Proc. 3rdWorkshop on Magneto-Plasma Aerodynamics in AerospaceApplications (Moscow, IVTAN, 2426 April 2001)

[17] Yarantsev D A, Leonov S B, Biturin V A and Savelkin K V2005 Spectroscopic diagnostics of plasma-assistedcombustion in high-speed flow AIAA/CIRA 13th Int. SpacePlanes and Hypersonic Systems and Technologies Conf.(Capua, Italy, 1620 May 2005) AIAA-2005-3396

[18] Leonov S B, Biturin V A and Yarantsev D A 2005Plasma-induced ignition and plasma-assisted combustion inhigh speed flow Non-Equilibrium Processes, vol 2: Plasma,

Aerosols, and Atmospheric Phenomena ed G D Roy,S M Frolov and A M Starik (Moscow: Torus Press)pp 10415

[19] Leonov S and Bityurin V 2002 Hypersonic/supersonic flowcontrol by electro-discharge plasma application 11th

AIAA/AAAF Int. Symp. Space Planes and HypersonicSystems and Technologie (Orleans, 29 September4October 2002) AIAA-2002-5209

138

sergey b leonov and dmitry a yarantsev- plasma-induced ignition and plasma-assisted combustion in...

Documents