## Fluids

#### Flue gas condensation with condensate phase in Ansys CFX

• seppell91
Subscriber

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?