CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > ANSYS > CFX

Sinusoidal Expression

Register Blogs Members List Search Today's Posts Mark Forums Read

Like Tree1Likes
  • 1 Post By brunoc

LinkBack Thread Tools Search this Thread Display Modes
Old   April 2, 2014, 14:17
Default Sinusoidal Expression
New Member
Luke Osborne
Join Date: Apr 2014
Posts: 2
Rep Power: 0
LukeOsb is on a distinguished road
I'm modelling a tank rotating using Cfx. the tank rotates with a mixture of water and air. A model is shown here (the front and back faces are symmetry and the sides are free slip walls)

The expression I am using to rotate the tank in alternate directions is

if((t-tOn)>=0 [s], 0.3[rad s^-1]*sin((t-tOn)*2*pi/(4 [s])),0 [rad s^-1])

where tOn is a timestep of 0.075 [s]

which results in a change of angular velocity as shown

However I would like to pause the sinusoidal wave at its positive and negative peaks for a period (lets say 1 [s]) how can i modify my expression to do this? If there is a way to make a plus or minus sign I can modify my expression to do this, is this possible? or what other ways could I do this?

Thanks in advance,
LukeOsb is offline   Reply With Quote

Old   April 2, 2014, 17:46
Senior Member
Join Date: Mar 2009
Location: Brazil
Posts: 277
Rep Power: 20
brunoc is on a distinguished road
There are two ways to do that:

1) Generate the equation that does what you want, that is, use a sinusoidal wave for a period, then switch, to constant, then back to sinusoidal.


2) Create a table of your expression in Excel as a function of time and use that table as a 1D function in Pre. This might be an easier way to do it.
LukeOsb likes this.
brunoc is offline   Reply With Quote


cfx, flow, mixture, rotation, sinusoidal

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
[swak4Foam] outputTime in Swak function immortality OpenFOAM Community Contributions 20 October 6, 2022 12:08
writing execFlowFunctionObjects immortality OpenFOAM Post-Processing 30 September 15, 2013 06:16
How to install CGNS under windows xp? lzgwhy Main CFD Forum 1 January 11, 2011 18:44
CGNS lib and Fortran compiler manaliac Main CFD Forum 2 November 29, 2010 06:25
Lift, Drag Vs time chart,calculations Jamesd69climber CFX 8 February 17, 2005 17:23

All times are GMT -4. The time now is 23:44.