A hypersonic plasma power generator

Touryan, K. J.

doi:10.2514/3.2942

Cited by 24 publications

(21 citation statements)

References 6 publications

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“…A load connected between the cathode and anode completes the circuit. Applying Kirchhoff's law to this circuit E emf + Eir = 0 (2) and using the well known current flow equations at the two electrodes, I = It + Iiem -'eem exp (-eVe /kTej) Vem <(°a node I =t exp (-eVem/kTem) -Ieem Both of these temperatures must be suitable averages at each electrode because there is a continuous temperature drop from the stagnation point back towards the afterbody (see Figure 1). .…”

Section: B Power Generation -Theoretical Considerationsmentioning

confidence: 99%

Thermionic Power Generation from Reentry Vehicles

Touryan

Sluyter

1966

IEEE Trans. Aerosp. Electron. Syst.

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SUMARYTheoretical and experimental analyses are presented which describe the operation and characteristics of a hypersonic plasma generator for reentry vehicles. In Section I, the principle of the generator operation is outlined, previous results are briefly reviewed, and supporting arc tunnel experimental data are included. In Section II, the ionization enhancement by nose cone cesium seeding of the flow field is analyzed with special attention given to the nonequilibrium chemical reaction between cesium atoms and ionized air species. Section III extends the results of the previous two sections to reentry applications using several typical ballistic and super-orbital reentry trajectories. SECTION I A. INTRODUCTIONThe reentry phase of a vehicle is characterized by intense heating of the nose cone and by the generation of an ionized air region around it. The level of ionization is directly proportional to the gas temperature and pressure behind the shock wave that forms ahead of the reentry vehicle. This temperature, which can reach 15,000°K near the stagnation point, is a function of the vehicle Mach number. The nose cone surface temperature depends on the gas temperature behind the shock wave, as well as the type of heat shield used. Normally, this temperature is in the vicinity of 30000C where most ablative heat shields sublime. Such energy levels could be used rather simply to generate dc-power if the vehicle could be allowed to operate as an external thermionic generator. The present paper deals with this simple concept which was developed at the Sandia Laboratory over the last two years. The theory and experiments underlying the principle of operation of this generator have been published elsewhere. Reference 1 conta the initial results, which were done at the University of New Mexico under a contract from Sandia Laboratory, and Reference 2 gives more complete results with significant improvements over the first work.In the present paper, the power generator theory is outlined briefly with several modifications, and the most recent experimental results are included. These results are then extended to reentry environments and a detailed analysis of flight performance is made with several typical reentry configurations. Throughout the paper a special emphasis is put on nose cone seeding techniques, and calculations are made to demonstrate the improved output as a result of this seeding. B. POWER GENERATION -THEORETICAL CONSIDERATIONSThe schematic of a reentry body is shown in Figure 1. The nose cone serves as a thermionic emitter of electrons, according to the generalized Richardson-Dushman equation which, when integrated over the nose cone area is expressed by 47rm k2 f(1-p)TT2(e) ex | -(T) ] X hT-FjJkTs . sine de do (1) The emitted electrons are conducted through the shock ionized air stream and collected over the afterbody which, because of its size, operates at a floating potential relative to the plasma, and serves as an anode or a collector. A load connected between the cathode and anode completes the ci...

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Section: B Power Generation -Theoretical Considerationsmentioning

confidence: 99%

Thermionic Power Generation from Reentry Vehicles

Touryan

Sluyter

1966

IEEE Trans. Aerosp. Electron. Syst.

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“…В настоящий момент по данной тематике нам известны только теоретические работы, связанные с численными оценками и математическим моделированием. Первые работы, в которых был описан способ генерации электрического тока при помощи термоэмиссионных материалов на поверхности гиперзвукового летательного аппарата, появились еще в 1960-х годах [6,7]. В этих работах проводится анализ и экспериментальное исследование новой конструкции термоэлектронного генератора электрического тока для летательных аппаратов.…”

Section: Introductionunclassified

“…Принцип такого генератора заключается в использовании термоэмиссионных материалов на поверхности головно-го обтекателя для генерации электрического тока под воздействием высоких температур вследствие аэродинамического нагрева. Авторами [6] получены уравнения для оценки получаемого на выходе генератора тока, выходной мощности и условий максимальной мощности. Чтобы смоделировать условия полета, тестовая модель помещалась в плазменную струю азота или аргона.…”

Section: Introductionunclassified

“…В работах [6,7] не обсуждается возможность применения термоэмиссионных материалов для активной теплозащиты ЭО. На тот момент достижение летательными аппаратами необходимых скоростей было невозможным, поэтому технология не получила развития.…”

Section: Introductionunclassified

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Исследование Эффекта Электронного Охлаждения. Обзор Современного Состояния Работ

Безверхний¹,

Бобашев²,

Колычев³

et al. 2019

Журнал Технической Физики

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“…In the 1960s there was a push to use thermo-electric materials on the nose of re-entry vehicles and collect the emitted electrons as a source of power generation. 5,6 Experiments were performed using the plasma arc tunnel at Sandia Corporation using a range of different flow conditions, emissive materials, and geometries. 7 This study aims to assess the computational fluid dynamics (CFD) modeling approach using these experiments.…”

Section: Introductionmentioning

confidence: 99%

Comparisons of Computations with Experiments for Electron Transpiration Cooling at High Enthalpies

Hanquist

Boyd²

2015

45th AIAA Thermophysics Conference

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A modeling approach for electron transpiration cooling of high enthalpy flight is compared to a set of experiments performed in a plasma arc tunnel for nitrogen and argon. The comparisons include nitrogen and argon flow at high enthalpies, 12,000 btu/lb and 5,000 btu/lb respectively, with a Mach number of 2.5 to 3. Converting the provided enthalpies and Mach numbers to freestream temperatures and velocities is discussed. The numerical approach is described including implementation of a thermionic emission boundary condition. Also described is the implementation of a finite-rate chemistry model for argon ionization. Different emissive materials are also investigated including graphite and tungsten. The comparisons include two different geometries with different leading edge radii. The numerical results produce a wide range of emitted current due to the uncertainties in freestream conditions and emissive material properties, but still agree well with the experiments. Future work recommendations are provided that may improve the physical accuracy of the modeling capabilities used in the comparisons.

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A hypersonic plasma power generator

Cited by 24 publications

References 6 publications

Thermionic Power Generation from Reentry Vehicles

Thermionic Power Generation from Reentry Vehicles

Исследование Эффекта Электронного Охлаждения. Обзор Современного Состояния Работ

Comparisons of Computations with Experiments for Electron Transpiration Cooling at High Enthalpies

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