Tonus code allows to simulate the distibution, combustion
and detonation of hydrogen in the case of severe accident in a pressurized water
reactor. The first part of this work is a verification of CONDENS procedure,
for Air-Steam-Helium gas mixture against experimental data base. The results
show that we have to pay attention using this procedure if there is a lot amount
of light gas.
The second part is a validation of Low Mach Asymptotic Compressible solver,
implemented in CAST3M code, to simulate compressible multicomponent flow.
We have made a comparison between this model and an analytical model
with a numerical test case. Good agreement have been obtained.