Problematic issues of energy parameters balance of liquid rocket engines

Аuthors

Beliayev E. N.^1*, Nassimento L. B.^2**, Kolomentsev A. I.^1***

1. Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, А-80, GSP-3, 125993, Russia
2. Instituto Tecnologico de Aeronautica, 12228-900, Sao Jose dos Campos, SP Brazil

*e-mail: belyaev72@rambler.ru
**e-mail: reitor@ita br
***e-mail: a.i.kolomentsev@yandex.ru

Abstract

Energy balancing of LRE is originally produced during developing of the new rocket engine, determining its characteristics, choice of pneumohydraulic scheme. At the initial stage of development, during the balancing of energy parameters previously established experience is taken into account. Based on this experience, the new developed engine has attainable values of pumps and turbines efficiency, the needed pressure for reliable cooling of the combustion chamber, the fuel spray nozzle components, regulatory units, etc.
The procedure of energy balancing of parameters of LRE is performed from the beginning of the new engine to the ideas of his moral death and removal from the production. It is necessary because many of the measured or calculated parameters must be constantly refined. Determination of the thermodynamic characteristics of the products of components combustion, especially in gas generator is main task for energy balancing. It is because the gas flow burn in the gas generator at mixture ratio of fuel components significantly different from the stoichiometric, and taking into account the real properties of turbines gas. It can significantly change the energy balance of the engine and its influence on the choice of pneumohydraulic scheme.
The article presents a comparison of operating temperatures in oxidizing gas generators of engines 11D58M SG, RD-120 and RD-191 and calculated temperatures by programs CEA, RPA and Astra.4/pc
The calculations were performed taking into account the temperature of oxygen and hydrocarbon fuel entering in the gas generator. Comparison shows that, in actual temperature oxidizing gas of generator differs significantly from the calculated values. Comparison shows that, in actual conditions the temperature oxidizing gas of generator differs significantly from the calculated values. This is due to at least two factors, firstly the fact that the kinetics of the combustion of fuels at large or small level of mix ration is not well understood. This is confirmed by the results of calculations. Secondly, the organizations of mixing inside gas generator providing a substantial influence on the final temperature of the gas at the outlet of the gas generator at the large levels of mix ration.
Conclusions: during energy balancing of LRE non- ideal of chemical reactions (for calculation of the thermodynamic parameters of the combustion products) and difference between the properties of a real gas from ideal (for determining the power of turbines) must be considered.

Keywords:

liquid rocket engines, energy balance, thermodynamic performance, non-ideal chemical reaction

References

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