Concetration should decrease when heating up a gas?

Hi,

I´m modelling a gas that initially is entering to my geometry, with a given velocity, at a fixed concetration of H2 and at 25°C. In this geometry there is a barrier that is at 1100°C that is in conctact with the flowing gas. This will cause that the gas heats up, and thus that its density changes (the flow is compressilbe Ma<0.3).

However, if the density changes when the gas is being heated up, I would expect that the concetration of H2 also does. This is not ocurring, any ideas of why this is ocurring?

I'm modelling the concetration of H2 with transport of diluted species module.


Thanks,

Juan Felipe