Характеристики неравнотемпературных систем концентратор-приемник солнечного теплового ракетного двигателя

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Характеристики неравнотемпературных систем концентратор–приемник…
ISSN 0236-3941. Вестник МГТУ им. Н.Э. Баумана. Сер. Машиностроение. 2017. № 2 81
NONISOTHERMAL CONCENTRATOR–ABSORBER SYSTEM
PERFORMANCES FOR SOLAR THERMAL PROPULSION
S.L. Finogenov
A.I. Kolomentsev
Moscow Aviation Institute (National Research University), Moscow, Russian Federation
Abstract Keywords
The study examined solar thermal propulsion (STP) with
nonisothermal concentrator-absorber system (CAS) as a
power source with high energy efficiency. We used radial-type
nonisothermal absorbers, where current temperature of pro-
pulsive mass (hydrogen) heating corresponds to radiant flux
distribution in the focal light spot of parabolic mirror. We
analyzed the thermal processes in the radial absorber of maxi-
mum nonisothermal type assuming no radial overflowing
warmth, which is justified for mirrors with a diameter of more
than 10 m. The study gives the results of numerical integration
of absorber radius temperature distribution equation in the
differential form for various accuracy parameter values. More-
over, we developed an algorithm for iterative calculation of
hydrogen outlet temperature of concentrator-absorber system,
determining the specific impulse of the engine. The paper
presents the flowchart of the iterative calculation. We used
numerical integration data for stating the regress relations,
determining the nonisothermal CAS efficiency and updating
the existing relations at high temperatures and accuracy pa-
rameter values, expedient for high-energy inter-orbital ma-
neuvers. The study determined CAS rational performances in
relation to the “solar” upper stage of “Soyuz-2-1b” launcher
with the STP use in LEO-to-GEO mission within 60 days.
Findings of the research show that if we select optimum per-
formances of the extreme nonisothermal CAS in ranges of the
concentrator accuracy parameter  = 0,8…1,1 and absorber
temperature 3200…3400 K, the payload mass approaches to 2
600 kg. At permissible decrease in payload mass (3…4 %) the
CAS rational characteristics correspond to accuracy parameter
 = 1,3…1,5 and heating temperature 2800…3000 K; thus
requirements to the CAS and its orientation conditions to the
Sun are simplified. In this case the permissible angle to the Sun
tracking corresponds to 2…2,2 and can be realized rather
simple by the state-of-the-art technology. The chosen CAS
performances make it possible to provide ballistic efficiency of
the solar upper stage with such STP up to 20% higher com-
pared to double-staged CAS use. As compared with the single-
staged STP, the payload mass increase up to 1000 kg, and
exceeds modern liquid propulsion efficiency up to 1 500 kg
Solar thermal propulsion, concen-
trator-absorber system, noniso-
thermal heating, solar high-tempe-
rature source of heat, geostationary
orbit, upper stage