[mengyue1]

hi guys, i am simulating the diffusion of h2 in a containment. The mixture consisting of h2 and h2o is injected into a containment, the total mass flow rate of the mixture is 1.0 kg/s and the mass fractions of h2 and h2o are 0.2 and 0.8, respectively. At first, the containment is full of h2o and air. in CFX-Pre, i set the total mass flow rate and the component(h2 and h2o) mass fraction.
when the calculation is completed, i find the the h2 mass fraction at inlet is not 0.2 which i set in the CFX-Pre. (By the way, i use areaAve(H2. mass fraction)@INLET to obtain the h2 mass fraction at inlet). i am confused about this, dose anyone know how to solve this problem?
Thanks in advance!