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High Temperature Material Processes (An International Quarterly of High-Technology Plasma Processes)

An International Journal

ISSN for PRINT: 1093-3611

Institutional price:	$604.00
Issues per year:	4

Best Paper Award Selection - Editorial Board Site

2005, Volume9

156 pages

DOI: 10.1615/HighTempMatProc.v9.i3

Issue price - $144.00

POST-FLIGHT ANALYSES OF THE OREX CATALYCITY EXPERIMENT

A. Enzian
CNES, F-91023 Evry, France

T. Ito
JAXA, Chofu, Tokyo, Japan

M. Balat-Pichelin
IMP-CNRS, Odeillo, France

A. Desportes
CORIA-CNRS, Rouen, France

P. Vervisch
CORIA-CNRS, Rouen, France

C. Guyon
Laboratoire de Génie des Procédés Plasmas et Traitement de Surfaces, 11 rue Pierre et Marie Curie, 75231 Paris Cedex, France

Jacques Amouroux
Laboratoire de Génie des Procédés Plasmas et Traitement de Surface − Université Pierre et Marie Curie − Paris 6 - ENSCP, 11, rue Pierre et Marie Curie, 75231 Paris Cedex 05, France

Ph. Tran
EADS-ST, Les Mureaux, France

N. Sauvage
EADS-ST, Les Mureaux, France

F. Thivet
ONERA, Toulouse, France

ABSTRACT

Catalytic recombination of dissociated atmospheric oxygen and nitrogen is a major heat source for re-entry vehicles beyond Mach 10. Present thermal protection systems are designed to the extreme assumption of full catalycity. However mass, performance, and cost considerations of future reusable launch vehicles require that their thermal protection system is designed to the more realistic assumption of partial catalycity. With this in mind, the authors of this paper have studied the catalytic behavior of a coated C/C material as it was used for the heat shield of the OREX re-entry capsule. In this presentation, we will report on the laboratory measurements of the atomic oxygen recombination coefficient and its associated coefficient for thermal accommodation. The recombination coefficient was determined in plasma test chambers by actinometry and in plasmatron at 200 and 2000 Pa, respectively. The results show an effective recombination coefficient of the order of 1% (600 K - 1900 K). Unlike Stewart and the Bruno models, we did not observe a strong temperature dependency of the effective recombination coefficient, neither in the laboratory data nor in the flight data. The observed behaviour can be explained by the Cacciatore model on silica.