Mechanism of shock wave merging in a laser jet engine

Аполлонов, В. В.; Tishchenko, V. N.

doi:10.1070/qe2004v034n12abeh002927

Cited by 9 publications

(11 citation statements)

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“…In the model considered in [12][13][14], the pulsed and stationary regimes are possible. Figure 1 explains the specific features of these regimes.…”

Section: Methodsmentioning

confidence: 99%

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Stationary force production: experimental and theoretical investigations

Аполлонов

2008

High-Power Laser Ablation VII

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The results of theoretical and experimental investigations on methane pyrolysis with infiltration through a heated porous matrix generated from various carbon materials are presented. The features of mathematical models, kinetic relationships of process are discussed. The mathematical model of process shares on external problem (a flow of particles in an external stream) and internal problem (reaction in particle porous). The heat and mass transfer for the average (over the reactor cross section) parameters, ignoring the heat transfer in gas by thermal conductivity, is described by unsteady-state one-dimensional differential equations in partial derivatives. For the mathematical description of process kinetics of methane decomposition the approach is used by which the soot formation is treated as a chain radical process. The porous media is represented by a system of large enough particles. In its turn, every macroparticle consists of finer particles, which are also composed of microparticles, etc. Calculating programs were used for modeling and efficiency analysis of technological installations for technical carbon production in a regenerative heater, filled by a ceramic nozzle and for similar purposes concerning carbon (oven soot) in autothermal torch process of partial gas oxidation by air at a surplus factor of oxidizer in relation to stoichiometry 0.4-0.5 at pressure close to atmospheric on Sosnogorsk Gas-Processing Plant. Experiment descriptions and techniques for experimental realization are given. These results are used as fundamentals for new technologies considering pyrocarbon materials production in the continuous operation reactor.

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“…In the model considered in [12][13][14], the pulsed and stationary regimes are possible. Figure 1 explains the specific features of these regimes.…”

Section: Methodsmentioning

confidence: 99%

“…To solve these problems, it was proposed to use repetitively pulsed radiation with f~ 100 kHz, the optical pulsating discharge (OPD), and the effect of merging of shock waves produced by the OPD [12][13][14]. The merging criteria were confirmed in experiments [15].…”

Section: Introductionmentioning

confidence: 95%

Stationary force production: experimental and theoretical investigations

Аполлонов

2008

High-Power Laser Ablation VII

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“…The mechanism of SW merging operates in various media in a wide range of laser pulse energies. The results of investigations show that the efficiency of the high repetition rate pulse-periodic laser radiation can be increased substantially when a QSW is used for producing thrust in a laser engine [13,14].…”

Section: Matrix Of Reflectorsmentioning

confidence: 97%

“…It was pointed out in papers [26] that the LAJE can find applications for launching space crafts if ~ 100-kJ repetitively pulsed lasers with pulse repetition rates of hundreds hertz are developed and the damage of the optical reflector under the action of shock waves and laser plasma is eliminated. These problems can be solved by using high pulse repetition rates (f~ 100 kHz), an optical pulsed discharge, and the merging of shock waves [12,13]. The efficiency of the use of laser radiation in the case of short pulses at high pulse repetition rates is considerably higher.…”

Section: The Impact Of Thermal Actionmentioning

confidence: 99%

“…The momentum increment per period can be expressed in terms of the coupling coefficient J as δ Pi = JQ, where Q [J] is the laser radiation energy absorbed in a spark. The condition δ Pi = δp s gives the relation: (6) between the basic parameters of the problem: W = Qf is the absorbed average power of repetitively pulsed radiation, and J ≈ 0.0001 -0.0012 N s J -1 [3,13,26]. The action time of the compression phase on the reflector is t a ~ R c /V, where V≈ k 1 C 0 is the shock-wave velocity in front of the wall (k 1 ~ 1.2) and C 0 ≈ 3.4 × 10 4 cm s -1 is the sound speed in air.…”

Section: The Impact Of Thermal Actionmentioning

confidence: 99%

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