Mole Fraction inlet is different from boundary conditions

HelloHelo · March 28, 2024, 08:56

Hi! I've been simulating a gas entering a liquid through small holes. I'm using the Eulerian model, but I also simulated using the mixture model. In both situations, I set the mole fraction of component X in the gas at the inlet boundary conditions. However, when I start running the calculation, the mole fraction at the inlet surface of component X is different from the one I set. I've tried activating the diffusion inlet, but it didn't work either.

bloodflow · April 1, 2024, 17:09

Quote:

Originally Posted by HelloHelo

Hi! I've been simulating a gas entering a liquid through small holes. I'm using the Eulerian model, but I also simulated using the mixture model. In both situations, I set the mole fraction of component X in the gas at the inlet boundary conditions. However, when I start running the calculation, the mole fraction at the inlet surface of component X is different from the one I set. I've tried activating the diffusion inlet, but it didn't work either.

Are you 100% you haven't specified it as a mass fraction? The default input to species is mass fraction, not mole fraction. Alternatively, Fluent is probably lying to you, if you are generating this output before solving for >1 iteration.

HelloHelo · April 4, 2024, 19:50

I am sure. There is a box you check to input as mole fraction. I've run some other tests and now it only changes to something different from my input when I activate the reactions. But I don't think the inlet should change once it's just got in contact with the other component.

March 28, 2024, 08:56	Mole Fraction inlet is different from boundary conditions	#1
HelloHelo New Member Join Date: Mar 2024 Posts: 2 Rep Power: 0	Hi! I've been simulating a gas entering a liquid through small holes. I'm using the Eulerian model, but I also simulated using the mixture model. In both situations, I set the mole fraction of component X in the gas at the inlet boundary conditions. However, when I start running the calculation, the mole fraction at the inlet surface of component X is different from the one I set. I've tried activating the diffusion inlet, but it didn't work either.

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April 4, 2024, 19:50		#3
HelloHelo New Member Join Date: Mar 2024 Posts: 2 Rep Power: 0	I am sure. There is a box you check to input as mole fraction. I've run some other tests and now it only changes to something different from my input when I activate the reactions. But I don't think the inlet should change once it's just got in contact with the other component.