Parameter calculation and design of an autonomous thermal cutting machine based on the combustion chamber of a low-thrust rocket engine

Due to the tough requirements for the environmental safety of the space objects operation, the use of methane-based fuel together with oxygen is a promising direction in developing a new generation of rocket and space technology, including low-thrust rocket engines. When developing low-thrust rocket engines running on oxygen-methane fuel, a mathematical experiment helps to identify the determining factors that affect the quality of the working process in the combustion chamber and to make a calculated optimization of the parameters for supplying fuel components to the combustion chamber. This contributes to a better understanding of the physics of the ongoing processes and leads to recommendations for the design of individual components of the combustion chamber. The numerical simulation enables us to optimize the geometry of the combustion chamber in order to obtain the maximum value of the chamber coefficient, which for an isobaric combustion chamber can be equal to the coefficient of the flow complex. This approach can significantly reduce the number of expensive bench tests. The paper introduces a physical and mathematical model of the workflow in the combustion chamber of a low-thrust rocket engine and gives a comparative analysis of the calculation results for various modifications of the original geometry of the low thrust rocket chamber. Recommendations are given for changing the initial geometry of the combustion chamber in order to increase the coefficient of the flow complex while maintaining a satisfactory thermal state of this chamber.

Download Full-text

Numerical study of the influence of the physicochemical liquid fuel properties on the efficiency of the low-thrust rocket engine working process

Engineering Journal Science and Innovation ◽

10.18698/2308-6033-2021-12-2138 ◽

2021 ◽

Author(s):

A.V. Novikov ◽

E.A. Andreev ◽

E.I. Bardakova

Keyword(s):

Combustion Chamber ◽

Numerical Study ◽

Rocket Engine ◽

Propulsion System ◽

Rocket Engines ◽

Space Technology ◽

Low Thrust ◽

Working Process ◽

Engine Combustion ◽

Parametric Studies

Low-thrust rocket engines are widely used in rocket and space technology for correcting the position of a spacecraft in orbit, for controlling motion along a trajectory, etc. Their number in the propulsion system can be from one to tens of units. Accordingly, the efficiency of their work significantly affects the perfection of the propulsion system as a whole. The object of the study was the low-thrust rocket engine combustion chamber operating according to the gas-liquid scheme. There were performed computational and parametric studies of various factor effects on the characteristics of the working process in the combustion chamber. The dependences of the coefficient of the consumable complex and parameters of the working process of the low-thrust rocket engine chamber on the influencing factors when using ethanol and kerosene as a fuel were calculated. A comparative analysis of the results of using these two components under similar conditions was carried out, which made it possible to reveal the influence of the physicochemical properties of the combustible component on the efficiency of the working process organization. The results obtained can be used in the design of low-thrust engines operating on the kerosene–oxygen and ethanol–oxygen propellants.

Download Full-text

Preliminary Studies on Non-Reactive Flow Vortex Cooling

Recent Patents on Mechanical Engineering ◽

10.2174/2212797612666190510115403 ◽

2019 ◽

Vol 12 (3) ◽

pp. 262-271

Author(s):

T.N. Rajesh ◽

T.J.S. Jothi ◽

T. Jayachandran

Keyword(s):

Combustion Chamber ◽

Inner Core ◽

Rocket Engine ◽

Injection Pressure ◽

Chamber Pressure ◽

Reactive Flow ◽

Stoichiometric Ratio ◽

Gaseous Oxygen ◽

Mixture Ratio ◽

Vortex Combustion

Background: The impulse for the propulsion of a rocket engine is obtained from the combustion of propellant mixture inside the combustion chamber and as the plume exhausts through a convergent- divergent nozzle. At stoichiometric ratio, the temperature inside the combustion chamber can be as high as 3500K. Thus, effective cooling of the thrust chamber becomes an essential criterion while designing a rocket engine. Objective: A new cooling method of thrust chambers was introduced by Chiaverni, which is termed as Vortex Combustion Cold-Wall Chamber (VCCW). The patent works on cyclone separators and confined vortex flow mechanism for providing high propellant mixing with improved degree of turbulence inside the combustion chamber, providing the required notion for studies on VCCW. The flow inside a VCCW has a complex structure characterised by axial pressure losses, swirl velocities, centrifugal force, flow reversal and strong turbulence. In order to study the flow phenomenon, both the experimental and numerical investigations are carried out. Methods: In this study, non-reactive flow analysis was conducted with real propellants like gaseous oxygen and hydrogen. The test was conducted to analyse the influence of mixture ratio and injection pressure of the propellants on the chamber pressure in a vortex combustion chamber. A vortex combustor was designed in which the oxidiser injected tangentially at the aft end near the nozzle spiraled up to the top plate and formed an inner core inside the chamber. The fuel was injected radially from injectors provided near the top plate and the propellants were mixed in the inner core. This resulted in enhanced mixing and increased residence time for the fuel. More information on the flow behaviour has been obtained by numerical analysis in Fluent. The test also investigated the sensitivity of the tangential injection pressure on the chamber pressure development. Results: All the test cases showed an increase in chamber pressure with the mixture ratio and injection pressure of the propellants. The maximum chamber pressure was found to be 3.8 bar at PC1 and 2.7 bar at PC2 when oxidiser to fuel ratio was 6.87. There was a reduction in chamber pressure of 1.1 bar and 0.7 bar at PC1 and PC2, respectively, in both the cases when hydrogen was injected. A small variation in the pressure of the propellant injected tangentially made a pronounced effect on the chamber pressure and hence vortex combustion chamber was found to be very sensitive to the tangential injection pressure. Conclusion: VCCW mechanism has been to be found to be very effective for keeping the chamber surface within the permissible limit and also reducing the payload of the space vehicle.

Download Full-text

Experimental Studies of Rocket Fuels Oxygen--Hydrogen, Oxygen--Methane Ignition by a Semiconductor Laser

Herald of the Bauman Moscow State Technical University Series Mechanical Engineering ◽

10.18698/0236-3941-2021-3-80-97 ◽

2021 ◽

pp. 80-97

Author(s):

S.G. Rebrov ◽

V.A. Golubev ◽

A.N. Golikov ◽

A.E. Morgunov

Keyword(s):

Semiconductor Laser ◽

Continuous Wave ◽

Rocket Engine ◽

Experimental Studies ◽

Operating Parameter ◽

Laser Ignition ◽

Low Thrust ◽

Ignition System ◽

Radiation Output ◽

Fuel Mixtures

The paper presents results of experimental studies aimed at introducing laser ignition of fuel mixtures into aero-space design practice. The source of ignition energy was a semiconductor laser featuring fibre radiation output, operating in a quasi-continuous wave mode. We carried out experiments for oxygen--hydrogen and oxygen--methane fuel types. The purpose of our research was to demonstrate the fundamental possibility of implementing fuel ignition by means of this type of laser, using a rocket engine igniter and a low-thrust rocket engine as examples. Employing semiconductor lasers directly as an ignition source for fuel mixtures in aerospace technology is attractive as it may feasibly reduce the requirements for thermal conditions during operation of the laser ignition system on board a rocket or spacecraft, as well as expand the range of permissible vibration and shock loads. The paper presents experimental results that delineate operating parameter ranges and operation cyclograms for the devices under consideration that ensured stable ignition of oxygen--hydrogen and oxygen--methane fuel mixtures; we also list the required power parameters for a semiconductor laser. The investigation revealed the specifics of using a semiconductor laser-based ignition system, which will be useful in developing laser rocket launching devices, ensuring reliable repeated on-off functionality

Download Full-text

Heat transfer in a rocket engine combustion chamber while geometry changing of the channel-slot solid fuel charge

Trudy MAI ◽

10.34759/trd-2020-111-5 ◽

2020 ◽

pp. 5-5

Author(s):

Boris Benderskyi ◽

Alena Chernova

Keyword(s):

Heat Transfer ◽

Combustion Chamber ◽

Solid Fuel ◽

Rocket Engine ◽

Fuel Charge ◽

Engine Combustion

Download Full-text

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

Aerospace ◽

10.3390/aerospace6120129 ◽

2019 ◽

Vol 6 (12) ◽

pp. 129 ◽

Cited By ~ 1

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.

Download Full-text