Laser Ignition of Liquid-Oxygen–Gaseous-Hydrogen Fuel in a Large-Scale Combustion Chamber

2019 ◽  
pp. 104-114
Author(s):  
S.G. Rebrov ◽  
V.A. Golubev ◽  
Y.P. Kosmachev ◽  
V.P. Kosmacheva
Keyword(s):  
Combustion Chamber ◽  
Large Scale ◽  
Rocket Engine ◽  
Laser System ◽  
Optical Breakdown ◽  
Gaseous Hydrogen ◽  
Liquid Oxygen ◽  
Research Centre ◽  
Laser Ignition ◽  
Experimental Chamber

The article presents a review of the results of studies of laser ignition of a cryogenic mixture (gaseous hydrogen and liquid oxygen) in an experimental combustion chamber, carried out at the bench testing facility of KBKhA (Voronezh). A laser ignition module specially designed at the Keldysh Research Centre and with parameters optimized for use in the rocket engine launch system was used during the experiments. Fuel ignition by the laser system occurred directly in the experimental chamber without the use of an ignition device or pre-chamber. To implement this ignition method, inflammation of the fuel in the chamber was carried out by focusing the laser radiation into the mixture, with the initiation of a spark of optical breakdown in the selected area with conditions favorable for the start of combustion. The results of the experiments confirmed the efficiency of the laser module during both standalone and firing tests, including multiple launches of the propulsion unit operated on a cryogenic mixture (gaseous hydrogen and liquid oxygen).

Repetitive laser ignition by optical breakdown of a LOX/H2 rocket combustion chamber with multi-injector head configuration

2017 ◽  
Vol 9 (3) ◽  
pp. 289-297 ◽  
Author(s):  
Michael Börner ◽  
Chiara Manfletti ◽  
Gerhard Kroupa ◽  
Michael Oschwald
Keyword(s):  
Combustion Chamber ◽  
Optical Breakdown ◽  
Laser Ignition

Propellant injection in a liquid oxygen/gaseous hydrogen rocket engine

1996 ◽  
Vol 12 (6) ◽  
pp. 1137-1147 ◽  
Author(s):  
Wolfgang Mayer ◽  
Hiroshi Tamura
Keyword(s):  
Rocket Engine ◽  
Gaseous Hydrogen ◽  
Liquid Oxygen

Methane Transcritical Behavior in the Cooling System of the HYPROB-BREAD LOX/LCH4 Demonstrator Rocket Engine

2015 ◽  
Author(s):  
D. Ricci ◽  
F. Battista ◽  
M. Ferraiuolo ◽  
V. Salvatore ◽  
M. Fragiacomo
Keyword(s):  
Cooling System ◽  
Fluid Dynamic ◽  
Rocket Engine ◽  
Liquid Oxygen ◽  
Research Centre ◽  
Channel Height ◽  
Rocket Engines ◽  
Combustion Gases ◽  
Cooling Jacket ◽  
Cfd Analyses

The HYPROB Program, developed by the Italian Aerospace Research Centre, has the aim of increasing the Italian system design and manufacturing capabilities on liquid oxygen-hydrocarbon rocket engines; the most important activity is represented by the development and testing of a ground engine demonstrator of three tons thrust based on methane as propellant. The demonstrator baseline concept is featured by 18 injectors and is regeneratively cooled by using liquid methane. The cooling system has a counter-flow architecture and is made by 96 axial channels; methane enters the channels in the nozzle region in supercritical liquid condition, is heated by the combustion gases along the cooling jacket and then is injected into the combustion chamber as a supercritical gas. The goal of the present paper is to describe the activities supporting the cooling jacket design, aiming at identifying the optimal configuration of the cooling channels. 3-D CFD analyses have been performed on different cooling channel arrangements, in terms of channel height and rib width. Moreover, simulations described the thermo-fluid dynamic behavior of methane by means of NIST real gas modeling and they were necessary to give the proper input to the thermo-structural analyses in order to verify the most critical sections of the cooling jacket.

Preliminary Studies on Non-Reactive Flow Vortex Cooling

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.

Development of 25N oxygen-kerosene thruster

2021 ◽  
Author(s):  
V.L. Salich
Keyword(s):  
Oxygen Supply ◽  
Rocket Engine ◽  
Experimental Chamber ◽  
Internal Cooling ◽  
Cylindrical Section

The paper introduces the scientific and technical groundwork obtained by the author and used as a basis for the development of an oxygen-kerosene rocket engine with a thrust of 25 N. This groundwork represents the results of research carried out on an experimental chamber developed by the author. The design of the chamber made it possible to study the effect of the configuration of the mixing element on its characteristics, the number of holes of oxygen supply to the internal cooling curtain, the length of the cylindrical section behind the curtain belt. The results of tests of various variants of the chamber and their analysis are presented. The results of tests of the developed engine, in which one of the camera variants is implemented, are given as well.

Critical Suction Peformance Test of Turbopump Assembly for a Liquid-Propellant Rocket Engine

2018 ◽  
Author(s):  
Hang Gi Lee ◽  
Ju Hyun Shin ◽  
Suk Hwan Yoon ◽  
Dae Jin Kim ◽  
Jun Hwan Bae ◽  
...  
Keyword(s):  
Liquid Nitrogen ◽  
Performance Test ◽  
Rocket Engine ◽  
Lightweight Design ◽  
Cavitation Number ◽  
Inlet Pressure ◽  
Liquid Oxygen ◽  
Pump Failure ◽  
Critical Cavitation ◽  
Suction Performance

This study investigates the behavior of a turbopump assembly during critical cavitation of the propellant pumps in the upper rocket engine of the Korea Space Launch Vehicle-II. Turbopumps operate under conditions involving low pressure at the pump inlet and high rotational speeds to allow for a lightweight design. This severe environment can easily cause cavitation to occur in the pump. This cavitation can then cause the pump operation to fail. As the cavitation number in the pump decreases below the critical point, the pump fails to operate. There is concern regarding the behavior of the turbopump assembly arising from pump failure due to cavitation. It is necessary to verify the problems that may occur if the turbopump assembly operates under extreme conditions, such like the critical cavitation. This study performed tests to investigate the breakdown of pumps in the turbopump assembly. Tests were conducted with liquid nitrogen, water, and high-pressure air instead of the mediums used during actual operation of liquid oxygen, kerosene, and hot gas. The turbopump was tested at the design point of 27,000 rpm, while the inlet pressure of each pump was controlled to approach the critical cavitation number. The turbine power output was maintained during the tests. The results show that the breakdown point of the oxidizer pump using liquid nitrogen, which is a cryogenic medium, occurred at a lower cavitation number than during an individual component suction performance test using water. The fuel pump using water, meanwhile, experiences breakdown at similar cavitation numbers in both tests. As the breakdown of the pump occurs, the power required by that pump decreases, and the rotational speed of the turbopump increases. Compared with individual pump suction performance tests, this breakdown test can be used to determine the limit of the propellant inlet pressure of the turbopump and to characterize the behavior of the turbopump assembly when a breakdown occurs. Vibrations were also analyzed for tests at a high cavitation number and at the critical cavitation number. The vibration increased with breakdown and notable frequencies were analyzed.

scholarly journals Measuring and assessing the impact of using volunteers in UK libraries: issues and methods

2014 ◽  
Vol 15 (3) ◽  
pp. 112-121 ◽  
Author(s):  
Judith Broady-Preston
Keyword(s):  
Systematic Review ◽  
Large Scale ◽  
Third Sector ◽  
Professional Staff ◽  
Research Centre ◽  
Content Type ◽  
Qualitative Approaches ◽  
Starting Point ◽  
Third Sector Organisations ◽  
The Impact

Purpose – The purpose of this paper is to examine a range of issues and methods in relation to measuring the impact of volunteer labour on the design and delivery of all types of library services. With the increasing use of volunteers to deliver library and information services in all sectors, managers need to assess their effectiveness and evaluate the impact of their use in relation to operational service design and delivery, and on the development of the profession and professional practice as a whole. Presented here is an initial scoping study, outlining a range of issues, methods and challenges for more detailed future investigation. Design/methodology/approach – A number of methodological challenges and perspectives are identifiable. Contemporary libraries exhibit increasing similarities with Third Sector organisations, namely a complex stakeholder community, and increasing use of volunteers to supplement or replace services delivered by professional staff. Therefore, a starting point for the research is a systematic review and analysis of the methodologies developed by the Third Sector Research Centre, and those studies in the ESRC contemporary Developing Impact Evaluation strand. As a rich picture is required, both quantitative and qualitative approaches are necessary, with the overall study adopting a mixed methods approach. Findings – This paper reports the findings of the preliminary documentary analysis, literature review and scoping aspects of a large-scale study. Originality/value – Research undertaken to date (June 2014) has failed to identify any published systematic review and examination of these issues.

Unsteady High-Order Simulation of a Liquid Oxygen/Gaseous Hydrogen Rocket Combustor

2015 ◽  
Vol 31 (6) ◽  
pp. 1715-1726 ◽  
Author(s):  
Markus Lempke ◽  
Peter Gerlinger ◽  
Martin J. Seidl ◽  
Manfred Aigner
Keyword(s):  
High Order ◽  
Gaseous Hydrogen ◽  
Liquid Oxygen
Sign in / Sign up

Export Citation Format

Share Document