The Laboratory of Industrial
Chemistry has worked for several years with cryogenics and gained a unique
expertise in the scope of contracts with SEP (European Propulsion Company
manufacturing rocket engines for the ARIANE rocket). During these test
campaigns, the laboratory had to master the problems encountered with the
manipulation of liquid nitrogen, liquid oxygen and pyrotechnics. Through
these contracts, a testbench - unique in a European university - was designed, built and evolved with
the different new needs. It proved very versatile to use and modify to
successfully address the different studies and problems encountered mainly
for the HM7B rocket engine (ARIANE IV third stage). We were also asked
to study the dispersion of liquid oxygen droplets in the main and secondary
combustion chamber and the start-up sequence of the gas generator. Then,
the bench was added with new devices and was to test the behaviour of a
LOX-flooded bearing in the LOX turbopump of the HM7B engine. This pump
feed the engine with liquid oxygen and the bearing is only lubricated by
the flow of liquid oxygen through it. After the failure of ARIANE IV flight
63, due to the malfunction of HM7B LOX pump, the work of our testbench
was decisive for the follow-on of the flights.
