Experimental Investigation and Modelling of the Ignition Transient of a Coaxial H2/O2-Injector

A test case has been defined to investigate experimentally and by numerical simulation the transient ignition phenomenology when igniting coaxial injected O2 and H2 by a laser. Using high-speed photography the temporal evolution of the flame and its anchoring at the injector could be visualized. From the analysis of the flame front movement flame velocities and convection velocities have been determined at specific phases during the ignition transient. 3D simulation were undertaken but not yet achieved., A first step using 2D axisymmetrical model allow to adjust grid, laser ignition modelization and to performe some parameter studies, Ignition was not reached in this configuration but preliminary results are encouraging. Finally, application to the VINCI was described where ignition uses a torch

THE MAXIMUM ENTROPY METHOD APPLIED TO LIQUID JET ATOMIZATION

organisée par l’ONERA et SUPAERO dans le cadre d’ILASS-EuropeInternational audienceA method is proposed to obtain by theoretical considerations the size distribution of sprays for a thick layer in the presence of gaseous flow. First, a maximum disturbance wave length is deduced from linear theory. This wave length is injected into a Stuart vortex in which the deformation of an initially planar liquid surface leads to the formation of a ligament. Droplets are formed by breakup of this transversal detached-or longitudinal attached-ligament and a theoretical mean diameter can be determined. Maximum entropy principles are then applied to deduce the size distribution

Un moteur-fusée à la loupe

International audienceEven though the technology of cryogenic rocket engines is well mastered today, and has been applied successfully in many launchers all over the world, research activities on the various elementary or coupled processes involved in these complex systems are still relevant and useful for future developments, cost reduction, and knowledge improvement.The Mascotte test facility was designed and built with this in mind twenty years ago.Since then, numerous configurations have been tested, enabling almost all of the phenomenainvolved in the operation of a rocket engine to be investigated, in a research lab environment, but nevertheless under representative conditions.Research items addressed on the Mascotte test rig include: injector concepts ; liquid oxygen jet atomization and combustion, new propellant combinations (methane instead of hydrogen), ignition, heat transfer at the chamber walls, high frequency instabilities, flow-separation in an over-expanded nozzle, plume and infrared signature.La technologie des moteurs-fusées cryotechniques est certes bien maîtrisée de nos jours et elle a été appliquée avec succès sur de nombreux lanceurs à travers le monde. Il n'en demeure pas moins que les activités de recherche sur les processus élémentaires qui interviennent dans ces systèmes complexes restent pertinentes et utiles aux futurs développements, la compétition internationale obligeant les industriels à accroître sans cesse les performances et la fiabilité tout en cherchant à minimiser les coûts.Le banc Mascotte a été conçu et construit il y a une vingtaine d'années en vue de ces objectifs. Depuis, de nombreuses configurations ont été expérimentées et, grâce à la flexibilité de l'installation, presque tous les aspects du fonctionnement d'un moteur-fusée peuvent être étudiés, ceci en restant dans un environnement de laboratoire de recherches tout en opérant dans des conditions réalistes du point de vue des températures, pressions et rapports de mélange.Les thèmes de recherche abordés sur le banc Mascotte comprennent les concepts d'injecteurs, l'atomisation et la combustion des jets d'oxygène liquide, les ergols, en particulier l'utilisation du méthane au lieu de l'hydrogène, l'allumage, les transferts thermiques aux parois, les instabilités de combustion, les décollements de jets dans les tuyères sur-détendues et la signature infrarouge des jets de post-combustion

Oxygen-methane combustion studies in the In Space Propulsion Programme

In the frame of the European Framework programme 7 (FP7), the In-Space Propulsion (ISP-1) project was initiated in 2009 with the objective of improving knowledge and techniques required by future space missions relying on cryogenic propulsion. One of the work packages addresses remaining open issues for the use of oxygen and methane for in-space propulsion: liquid-liquid injection, ignition and combustion at low pressure, film cooling and soot formation. This paper describes the work performed during the fifteen first months. Through theoretical analysis, modelling and experimental work, this project will serve the purpose of improving the maturity of technologies which are key elements of cryogenic space propulsion systems

Fault diagnosis benchmark for a rocket engine demonstrator.

International audienceA diagnosis benchmark was developed for the MASCOTTE test bench of ONERA/CNES. It consists of a CARINS Simulator of the bench, model-based fault diagnosis algorithms and firing tests results. The objective of this work was to demonstrate alternatives to the classical redline monitoring strategy used on the bench. A simplified model of the cooling circuit of the test bench was built and used to apply a parameter identification detection method and a Kalman filter. The diagnosis flags are obtained through analysis of the residuals via CUSUM tests. This article shows the results obtained and proposes an example of methodology to identify and validate performances of new diagnostic strategies

A new numerical method for pogo analysis

30th AIAA/ASME/SAE/ASEE Joint propulsion Conference, Indianapolis, IN (USA), June 27-29, 1994.(AIAA paper no 94-2884)SIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1994 n.101 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Characterization of a double swirl injector in a LOX/LCH4 fueled combustor on Mascotte test bench

The work presented in this paper was performed in the framework of the “ISP-1” project. A double swirl injector was designed and tested in a LOX/LCH4 fueled combustor on the Mascotte test facility at Onera, Palaiseau Center. Cold flow tests are first presented, followed by hot fire tests. Two highspeed intensified cameras were used, one for Onera and one for DLR, to record the chemiluminescence of OH* and CH*. Results with the double swirl injector were compared with a shear coaxial injector, commonly used in cryogenic rocket engines. The combustion stability of the flame was also investigated, depending on the injector’s geometry

Overview of the In-Space Propulsion (ISP-1) project

The intent of this publication is to provide an overview of the progress of the ISP1 project over the 2011-2012 period. In the frame of the European FP7 Collaborative Project, Focused Research Project Theme 7, the In- Space Propulsion (ISP-1) project GA# 218849 was initiated in 2009 with the objective of improving the knowledge and the techniques which are necessary for future space missions relying on cryogenic propulsion. The ISP-1 program is structured into five main work packages which deal with various technological issues associated to the development of a Low Thrust Cryogenic Propulsion system. It concentrates on liquid oxygen, liquid hydrogen, and liquid methane propellants. The subject addressed by the work packages are the LOX-methane combustion, the hydrogen embrittlement, the material compatibility and tribology in liquid oxygen, the energy management of low thrust propulsion system, and the development of electrically driven cryogenic turbopumps

The maximum entropy method applied to liquid jet atomization

Communication to : 15th Annual conference on liquid atomization and spray systems, Toulouse (France), July 05-07, 1999SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1999 n.142 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc