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Modeling evaporation of water. Need boundary condition to vary in space.
Posted 4 feb 2016, 01:41 GMT-5 Fluid & Heat, Heat Transfer & Phase Change, Computational Fluid Dynamics (CFD), Chemical Reaction Engineering Version 5.1 1 Reply
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I am trying to build a 2D model of air flowing over a thin film of water. In this model there is a constant heat flux on the bottom boundary of the thin water domain. The goal is to track how much water is being evaporated into the air stream.
I am using Laminar flow (spf), Heat Transfer in Fluids (ht), and Transport of Dilute Species (tds) interfaces.
The main issue I am having is modeling mass transport at the air water interface. Ideally the height of water should decrease with time, which I think can be achieved with Reaction nodes.
I would like to set the concentration at the air water interface to saturation concentration, but the air water interface changes position with time, (the water level decreases as more water is evaporated into the air stream). How can I make a concentration boundary condition vary with the height of the liquid water? How can I make the concentration at the liquid water interface stay constant , even as the position of that water air interface changes with time?
I am using Laminar flow (spf), Heat Transfer in Fluids (ht), and Transport of Dilute Species (tds) interfaces.
The main issue I am having is modeling mass transport at the air water interface. Ideally the height of water should decrease with time, which I think can be achieved with Reaction nodes.
I would like to set the concentration at the air water interface to saturation concentration, but the air water interface changes position with time, (the water level decreases as more water is evaporated into the air stream). How can I make a concentration boundary condition vary with the height of the liquid water? How can I make the concentration at the liquid water interface stay constant , even as the position of that water air interface changes with time?
1 Reply Last Post 16 feb 2016, 14:35 GMT-5
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Posted:
9 years ago
You may need to use deformed geometry module to provide movement of interface. The boundary mesh velocity can be calculated from the mass flux/density at interface.