Engineering Design and Analysis with Innovation

Close Icon
   
Contact Info     +44 141 582 1416

Pump Cavitation Analysis in ANSYS CFX (Part III)

 

This blog is the continuation of the series of blogs on the pump cavitation analysis in ANSYS CFX and to automate this process by using CEL (CFX Expression Language) and Perl script. The previous blogs can be found under the following links;

Pump Cavitation Analysis in ANSYS CFX (Part I)
Pump Cavitation Analysis in ANSYS CFX (Part II)

In this blog we are introducing to the post-processing step in the pump cavitation analysis in ANSYS CFX.

Cavitation

 

3.1 Opening the Results File:

  • Open the “.res” file from the run directory by double clicking on it or
  • Start CFX launcher from Start > All Programs > ANSYS [version] > Fluid Dynamics > CFX

Select the working directory and then click on CFD-Post [version] icon CFX Post or
Go to: CFX > CFD POST [version] or click on Load Results icon load results iconor press Ctrl+O on the keyboard, which will then launch CFD post. Specify the file name as and click Open.

CFX Launcher

This will open Domain Selector dialogue, select all the domains and click OK.

Domain Selector

 

3.2 Inserting Streamlines:

Go to: Insert > Streamline or click on Streamline icon  streamlines

This will open a new dialogue, select the name of streamlines and click OK.

Streamline Name

For Geometry tab select BC_In for Start From option and LiquidWater.Velocity in the Variable option.

Streamline Geometry tab

For Color tab choose variable in Mode option, while select LiquidWater.Velocity as the Variable with local Range.

Streamline color tab

For Symbol tab choose Tube as Stream Type, with 0.5 Tube Width and click Apply.

Streamline Symbol Tab

 

Streamlines will look like following.

Streamlines

 

3.3 Inserting Plane:

Go to: Insert > Location > Plane or click on Location icon Location Icon and select Plane, which will open a new dialogue, select the name of the Plane and click OK.

Select a plane that is parallel to the inlet face and passes through the blades of the impeller, use the following settings for the Geometry tab.

Plane Geometry Tab

For Color tab use the settings as described below, leave the default settings for Render and View tabs and click Apply.

Plane Color

 

The resulting plane will look like the following.

Plane Pressure

 

3.4 Inserting Pressure contour:

Go to: Insert > Location > Contour or click on Contour icon contour_icon , which will open a new dialogue, select the name of the Contour and click OK. In Geometry tab settings, select the name of the plane (already created in previous step) as the Location, pressure as the Variable and select local in the Range options. Leave the remaining settings as default and click Apply.

Pressure Contour Geometry Tab

 

The pressure contour will look like as the following.

Contour Pressure

 

3.5 Inserting Isosurface:

Go to: Insert > Location > Isosurface or click Location icon Location Icon and select Isosurface, this will open a new dialogue, select the name of the Isosurface and click OK.

Insert Isosurface

For Geometry tab, select VapourWater.Volume Fraction in the Variable setting, while 0.1 as the Value.

Isosurface Geometry Tab

For Color tab select constant Mode and red color in Color option. Leave the remaining settings as default and click Apply.

Isosurface Color

 

Also highlight the impeller blades for the cavitation to be more visible, the resulting Isosurface will look like the following.

Cavitation

 

5 Responses so far.

  1. Badi says:

    Hello great post. I am trying to simulate cavitation aswell but I have a few little problems. I do a transient cavitation simulation and when I turn the cavitation model off I still have Vapour in my Fluid after the first timestep. (I did initialize the right fractions) Is this normal? Does Ansys take the saturation pressure from the material library?

    I already subscribed and hope for an answer and maybe some help. :)

  2. admin says:

    Hi Badi,

    Please refer your query to blog@techcae.com with .ccl file and any pictures that you can. You should not get any cavitation when cavitation model is turned off. Probably you are trying to initialise transient analysis with cavitation model turned off from a steady state analysis result with cavitation model turned on.

  3. [...] 3 of a series of articles on pump cavitation analysis using CFX focuses on post-processing the CFD [...]

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>