Cryotribology (Cryo)

Image CryoThe CRYO group has a long experience in cryogenics for space applications. Indeed, since the late eighties, several space transportation applications requiring cryogenic fluids, especially nitrogen and oxygen (both liquid and gaseous) were studied.

 

Test rigs available at the cryogenic test site of the CRYO group mainly concern quite delicate high rotational speed components of cryogenic rocket engines. That is to say bearings and dynamic seals. These rigs gave successfully important results for the understanding and the improvement of the running of the so called components.

 

The CRYO group started with the study of some HM7B cryogenic engine (viz. the engine of the upper stage of Ariane, the european launcher) features as: the gas generator firing sequence, pressure losses measurement into the injectors and liquid oxygen jet visualization into the gas generator. For the same engine, the CRYO group was also in charge to understand the oxygen turbopump ball bearing behavior and to validate modifications of this bearing. The validation tests had been performed by achieving around 300 tests. Cool-down tests in liquid oxygen atmosphere for the “chamber” and “purge” valves of the Vulcain engine LOx circuit were also performed at the same time (Vulcain is the main cryogenic engine of Ariane).

 

In parallel, tribological test campaigns on pin-on-disk tribometer in both LOx and LN2 were carried out. These experiments were conducted in the framework of new cryogenic valve developments. Moreover, the CRYO group payed particular attention to liquid oxygen compatibility. Among other things, these tests were dedicated to the understanding of tribo-oxidation, foil bearing applications and new cage materials for ball bearing.

 

Recently, the CRYO group has been chosen to study the new seal package design of the Vinci engine (Vinci is the new cryogenic engine of the upper stage of Ariane 6, the future european launcher). The project has necessitated the design and the manufacture of a new test bench.


Contact(s) : BOZET Jean-Luc