scholarly journals Gas flow control in rocket engines

2021 ◽  
Vol 2021 (2) ◽  
pp. 60-77
Author(s):  
G.A. Strelnikov ◽  
◽  
A.D. Yhnatev ◽  
N.S. Pryadko ◽  
S.S. Vasyliv ◽  
...  
Keyword(s):  
Gas Flow ◽  
Rocket Engine ◽  
Rocket Engines ◽  
Liquid Propellant ◽  
Flow Perturbation ◽  
Liquid Injection ◽  
Thrust Vector ◽  
Liquid Propellant Rocket Engine ◽  
Generator Gas ◽  
Propellant Rocket

In the new conditions of application of launch vehicle boosters, space tugs, etc., modern rocket engines often do not satisfy the current stringent requirements. This calls for fundamental research into processes in rocket engines for improving their efficiency. In this regard, for the past 5 years, the Department of Thermogas Dynamics of Power Plants of the Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine has conducted research on gas flow control in rocket engines to improve their efficiency and functionality. Mechanisms of flow perturbation in the nozzle of a rocket engine by liquid injection and a solid obstacle were investigated. A mathematical model of supersonic flow perturbation by local liquid injection was refined, and new solutions for increasing the energy release rate of the liquid were developed. A numerical simulation of a gas flow perturbed by a solid obstacle in the nozzle of a rocket engine made it possible to verify the known (mostly experimental) results and to reveal new perturbation features. In particular, a significant increase in the efficiency of flow perturbation by an obstacle in the transonic region was shown up, and some dependences involving the distribution of the perturbed pressure on the nozzle wall, which had been considered universal, were refined. The possibility of increasing the efficiency of use of the generator gas picked downstream of the turbine of a liquid-propellant rocket engine was investigated, and the advantages of a new scheme of gas injection into the supersonic part of the nozzle, which provides both nozzle wall cooling by the generator gas and the production of lateral control forces, were substantiated. A new concept of rocket engine thrust vector control was developed: a combination of a mechanical and a gas-dynamic system. It was shown that such a thrust vector control system allows one to increase the efficiency and reliability of the space rocket stage flight control system. A new liquid-propellant rocket engine scheme was developed to control both the thrust amount and the thrust vector direction in all planes of rocket stage flight stabilization. New approaches to the process organization in auxiliary elements of rocket engines on the basis of detonation propellant combustion were developed to increase the rocket engine performance.

Large Rocket Engines for Space Vehicles and Missiles

1961 ◽  
Vol 65 (605) ◽  
pp. 321-331
Author(s):  
S. K. Hoffman
Keyword(s):  
Rocket Engine ◽  
Space Vehicles ◽  
Rocket Engines ◽  
Liquid Propellant ◽  
New Developments ◽  
Engine Component ◽  
Space Projects ◽  
History Of ◽  
Liquid Propellant Rocket Engine ◽  
Propellant Rocket

SummaryThe history of Rocketdyne's activity in the field of large liquid-propellant rocket engines is outlined in a chronological review of applicable United States ballistic and space projects. Within security limitations, major rocket engine component improvements and general fabrication techniques are discussed. The trends and new developments in liquid-propellant rocket engine designs are presented and a forecast of future engines is made.

scholarly journals Evaluation of the high-frequency oscillation parameters of a liquid-propellant rocket engine with an annular combustion chamber

2021 ◽  
Vol 2021 (1) ◽  
pp. 16-28
Author(s):  
O.D. Nikolayev ◽  
◽  
I.D. Bashliy ◽  
N.V. Khoriak ◽  
S.I. Dolgopolov ◽  
...  
Keyword(s):  
Finite Element ◽  
Combustion Chamber ◽  
Rocket Engine ◽  
Element Model ◽  
Numerical Approach ◽  
Rocket Engines ◽  
Liquid Propellant ◽  
Liquid Propellant Rocket Engine ◽  
Firing Tests ◽  
Propellant Rocket

The high-frequency instability (HF instability) of a liquid-propellant rocket engine (LPRE) during static firing tests is often accompanied by a significant increase in dynamic loads on the combustion chamber structure, often leading to the chamber destruction. This dynamic phenomenon can also be extremely dangerous for the dynamic strength of a liquid-propellant rocket engine with an annular combustion chamber. Computation of the parameters of acoustic combustion product oscillations is important in the design and static firing tests of such rocket engines. The main aim of this paper is to develop a numerical approach to determining the parameters of acoustic oscillations of combustion products in annular combustion chambers of liquid-propellant rocket engines taking into account the features of the configuration of the combustion space and the variability of the physical properties of the gaseous medium depending on the axial length of the chamber. A numerical approach is proposed. The approach is based on mathematical modeling of natural oscillations of a “shell structure of an annular chamber – gas” coupled dynamic system by using the finite element method. Based on the developed finite-element model of coupled spatial vibrations of the structure of the annular combustion chamber and the combustion product oscillations, the oscillation parameters of the system under consideration (frequencies, modes, and effective masses) for its dominant acoustic modes, the vibration amplitudes of the combustion chamber casing, and the amplitudes of its vibration accelerations can be determined. The operating parameters of the liquid-propellant rocket engine potentially dangerous for the development of thermoacoustic instability of the working process in the annular combustion chamber can be identified. For the numerical computation of the dynamic gains (in pressure) of the combustion chamber, a source of harmonic pressure excitation is introduced to the finite element model of the dynamic system “shell structure of an annular configuration – gas” (to the elements at the start of the chamber fire space). The developed approach testing and further analysis of the results were carried out for an engine with an annular combustion chamber (with a ratio of the outer and inner diameters of 1.5) using liquid oxygen – methane as a propellant pair. The system shapes and frequencies of longitudinal, tangential and radial modes are determined. It is shown that the frequency of the first acoustic mode in the case of a relatively low stiffness of the combustion chamber casing walls can be reduced by 40 percent in comparison with the frequency determined for a casing with rigid walls.

scholarly journals Influence of Ignition Channel on the Ignition Performance of Ignition Device

2018 ◽  
Vol 2018 ◽  
pp. 1-14
Author(s):  
Jiang Chang ◽  
Gongping Wu ◽  
Hanwei Tang
Keyword(s):  
Working Conditions ◽  
Inflection Point ◽  
Rocket Engine ◽  
Gas Pressure ◽  
Gas Velocity ◽  
Liquid Propellant ◽  
Liquid Propellant Rocket Engine ◽  
Ignition Device ◽  
Propellant Rocket ◽  
Solid Type

Based on relative theories of gas dynamics and computational fluid dynamics, the flow field computation software ANSYS Fluent was used to simulate the steady flow field of the solid type ignition device of liquid-propellant rocket engine in two working conditions (condition I: without ignition channel, condition II: with ignition channel). On this basis, the influence of ignition channel on the working characteristics of the solid type ignition device of the liquid-propellant rocket engine was analyzed and experimentally tested. The results showed that when the pressure in the combustion chamber was atmospheric pressure, under condition II, the gas velocity at the throat of the ignition device did not reach the sonic velocity, and the position of sonic velocity moved to the downstream section of the ignition channel. Compared to condition I, the gas velocity and energy at the ignition outlet increased, which would be beneficial for initial ignition, and the gas pressure and temperature at the throat increased as well, indicating that the structural strength at the throat should be evaluated. The gas flow, gas pressure, and gas temperature at the ignition outlet decreased compared to working condition I, yet the changes were small and would have minimal effect on the ignition performance. During the pressure increase process in the combustion chamber, the gas pressure, velocity, temperature, flow, and energy at the ignition outlet experienced a steady stage in both working conditions before coming to an inflection point. The inflection point under condition II is smaller than that under condition I. To improve the ignition reliability, the working pressure of the ignition device should be further increased.

scholarly journals Liquid-Propellant Rocket Engine Throttling: A Comprehensive Review

2010 ◽  
Vol 26 (5) ◽  
pp. 897-923 ◽  
Author(s):  
Matthew J. Casiano ◽  
James R. Hulka ◽  
Vigor Yang
Keyword(s):  
Rocket Engine ◽  
Liquid Propellant ◽  
Comprehensive Review ◽  
Liquid Propellant Rocket Engine ◽  
Propellant Rocket

scholarly journals Influence of Polyisobutylene Kerosene Additive on Combustion Efficiency in a Liquid Propellant Rocket Engine

Aerospace ◽  
2019 ◽  
Vol 6 (12) ◽  
pp. 129 ◽  
Author(s):  
Igor Borovik ◽  
Evgeniy Strokach ◽  
Alexander Kozlov ◽  
Valeriy Gaponov ◽  
Vladimir Chvanov ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Film Cooling ◽  
Rocket Engine ◽  
Combustion Efficiency ◽  
Liquid Propellant ◽  
Gaseous Oxygen ◽  
Wall Film ◽  
Measurement Results ◽  
Liquid Propellant Rocket Engine ◽  
Propellant Rocket

The combustion of kerosene with the polymer additive polyisobutylene (PIB) was experimentally investigated. The aim of the study was to measure the effect of PIB kerosene on the efficiency of combustion chamber cooling and the combustion efficiency of the liquid propellant for a rocket engine operating on kerosene and gaseous oxygen (GOX). The study was conducted on an experimental rocket engine using kerosene wall film cooling in the combustion chamber. Fire tests showed that the addition of polyisobutylene to kerosene had no significant effect on the combustion efficiency. However, analysis of the wall temperature measurement results showed that the use of PIB kerosene is more effective for film cooling than pure kerosene, which can increase the efficiency of combustion chamber cooling and subsequently increase its reliability and reusability. Thus, the findings of this study are expected to be of use in further investigations of wall film cooling efficiency.

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