Learning Forum

[seppell91]

Hello everyone,

I've got a problem in Ansys CFX (2019 R2).

I'm writing my master thesis about Flue gas condensation in a pipe.

 

At the moment if got a flow calculation with following settings:

The 3d model is basically a tube (d = 16 mm, l =500 mm) where only the fluid domain is calculated.

I created two Materials. 

•   Condensat: Homogeneous Binary Mixture with Saturation Properties set to Antoine Equation with Water and Water Ideal Gas


•   Flue Gas: VAriable Composition Mixture with Water Ideal Gas and Air Ideal Gas

In the Fluid-Domain settings are as follows:

• Basic Settings: 1 Fluid (Flue Gas) as Continuous Fluid, Reference Pressure 1 [atm]


• Fluid Models: Thermal Energy activated, Turbulence SST. Wall Condensation Model: Concentration Boundary Layer Model (Air Ideal Gas = Constraint, Water Ideal Gas =Transport Equation with the Condensable Option and the "Condensat"-Material als HBM)

The inlet conditions are as follows:

• Normal speed 1m / s


• Static Temperature 100 ° C


• Component Details: Water Ideal Gas = 0.16 mass fraction

The Outlet is set to an average Pressure of 0 Pa.

Die Wandbedingungen:

• No Slip Wall


• Smooth Wall


• Temperature 364 K


• Component Details :Water Ideal Gas = Wall Condensation Model
  
  
  

This Calculation works fine. But I want to create a 2nd Phase for the liquid condensate. 
I've tried to extend the Material "Flue Gas" with the component water and set an Boundary Source on the Wall (Water.mf -> Flux with the negative Condensate rate of Water Ideal Gas). But that did not bring the desired effect of a free water surface.

Can anyone help me with the Settings for a Wall Condensation with a Water Phase?

Or do I need another model for this? 

Thanks for your Help.
Seppell

 Edit: I have to model this in Ansys CFX!! 

[DrAmine]

Is not supported directly. What you want to do is resolving the water film and this is not what the wall condensation model will do.