DIFFUSION-VACUUM TECHNOLOGY OF MANUFACTURING LARGE AXISYMMETRIC ASSEMBLIES OF METAL MESH MATERIALS FOR HEAT EXCHANGE PATHS

Requirements for improving the reliability, service life, and increasing a specific pulse of liquid-propellant rocket engines justify a need for transfer to new designs and manufacturing technologies of regenerative engine cooling system. The paper describes a advanced diffusion-vacuum technology of manufacturing a regenerative cooling circuit for liquid-propellant rocket engine based on the concept of inter-channel coolant transpiration through a porous metal mesh material. The method of diffusion welding of metal wire mesh in vacuum makes it possible to obtain large axisymmetric blanks of metal mesh materials necessary to manufacture the regenerative cooling path of the liquid-propellant rocket engine and recuperative heat exchanger (RHE). The possibility of developing a high-efficient low-gradient porous heat exchange path obtained using a metal mesh material (MMM) has been experimentally confirmed. It is recommended to use metal woven cloth and twill filter screens of standard size П24–П60, С120 as a basic material for manufacturing MMM. Key words: diffusion-vacuum technology, porous mesh material, regenerative cooling system, inter-channel coolant transpiration.

Procedure for determining the effect of internal and external factors on the startup thrust spread of a liquid-propellant rocket engine

Despite of the package of measures to adjust a liquid-propellant rocket engine (LPRE) to a specified operating regime, minimum acceptable spreads in the geometrical parameters and operating conditions of its units and assemblies steel remain. These internal factors together with external ones (the pressure and temperature of the propellant components at the engine inlet) govern the engine thrust spread. To provide an acceptable engine thrust spread according to the engine requirements specification, it is important to know the spread value as early as at the stage of off-engine tryout of the engine units and assemblies. The aim of this work is to develop a procedure for calculating the effect of external and internal factors on the LPRE startup thrust spread. This paper presents a procedure for determining the effect of internal and external factors on the LPRE startup thrust spread. The procedure includes the development of a mathematical model of engine startup that accounts for the maximum number of internal factors, the choice of internal factors that produce the maximum effect on the LPRE startup thrust spread, the choice of a method for specifying the external and internal factor spread, engine startup calculations at different combinations of external and internal factor spread values, engine thrust spread determination, determining the statistical and the theoretical distributions of the 90 percent thrust time spread and the steady thrust spread, and assessing their goodness of fit using Pearson’s chi-squared test. The paper gives an example of calculating the effect of the external and internal factor spread on the LPRE startup thrust spread for a staged-combustion oxidizer-rich sustainer LPRE. Using the results of previous calculations, 12 internal factors that produce the maximum effect on the engine startup thrust spread are identified. It is shown that the calculated spread of the 90 percent thrust (combustion chamber pressure) time lies in the range – 0.08220s to +0.07300s about its nominal value, and the calculated steady engine thrust (combustion chamber pressure) spread lies in the range –6.4 percent to +6.6 percent of the nominal thrust. Using Pearson’s chi-squared test, an estimate is obtained for the goodness of fit of the anticipated theoretical distributions of the 90 percent thrust time spread and the steady thrust spread to the obtained statistical ones.

Experimental Analysis of Swirl Fuel Injector in Liquid Propellant Rocket Engine

Fuel injector for a liquid rocket is a very important component since a small difference in its design can drastically affect the combustion efficiency. The primary function of the injector is to break the fuel up into very small droplets. The concept of this project is to perform the fuel atomization with the desired cone angle. This atomization is achieved by passing the fuel through a swirl fuel injector which is connected to the fuel tank and air compressor. Three different orifices of various diameters are designed with different cone angles. The experimental setup consists of a fuel injector with the swirler inside, which is made up of brass with two different vane angles. The air compressor is used for pressurizing the fuel through the injectors. The cold flow experiment is conducted by passing the mixture of air and fuel to get the atomization. The injector is tested with various pressures ranging from 3 to 7 bar for the two cone angles with varying orifice diameters and the different spray patterns are captured. The results are compared, tabulated and correlated with existing values.

The concept of the auxiliary propulsion system of the III stage of the Soyuz launch vehicle

The paper introduces a concept of creating an auxiliary propulsion system for the III stage of the Soyuz launch vehicle. The concept is aimed at reducing the cost of launching a payload into low Earth orbit. The study describes the auxiliary propulsion system and its constituent elements and gives the results of a preliminary calculation of the main characteristics of a low-thrust engine. Within the research, we developed a sketch layout of the auxiliary propulsion system integrated into the 14D23 liquid propellant rocket engine and analyzed the mass characteristics of the constituent elements and the greatest contribution to the total mass of the propulsion system. The proposed propulsion system is distinguished by electric drives for the power supply system pumps used instead of the turbine drive. This auxiliary propulsion system, combined with a 14D23 liquid propellant rocket engine, powered by oxygen-naphthyl propellants, is proposed for use in the III stage of the Soyuz-2-1b launch vehicle.

Gas flow control in rocket engines

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.

75th anniversary of S.P. Korolev Rocket and Space Corporation Energia

The article briefly discusses the key achievements of the enterprise over 75 years from the formation of OKB-1 headed by S.P. Korolev for producing intercontinental range missiles to the current status of RSC Energia being the country’s and world leader in manned space flight. The developed intercontinental missiles R-7 and a closed-loop oxygen-hydrocarbon liquid-propellant rocket engine provided the basis for developing integrated launch vehicles which were used to launch the world’s first Earth satellite, the first cosmonaut on the Earth, automatic interplanetary stations to the Moon, Venus, Mars. The diversification of the enterprise impeded S.P. Korolev to concentrate on manned space flights, and he initiated the transfer of development and manufacture of combat missiles to V.P. Makeev DB, integrated launch vehicles to TsSKB Progress, communication and other satellites to M.F. Reshetnev ISS, lunar and interplanetary stations to S.A. Lavochkin NPO. In the 1980s under the guidance of V.P. Glushko the Energia super-heavy launch vehicle and Energia–Buran system in unmanned configuration were developed and successfully launched on the first try. The Salyut manned single-module orbital stations, Mir multifunctional multi-module space laboratory and successfully operating upgraded manned transportation (Soyuz) and logistics (Progress) spacecraft were developed. In the hard times of 1990s, RSC Energia under the guidance of Yu.P. Semenov saved the national cosmonautics through commercial research performed on the Mir station. At present, RSC Energia together with Khrunichev Space Center is completing the stage of ground tests of a multipurpose laboratory module and is manufacturing modules for a promising near-Earth manned station.