# time step for unsteady turbulent flow

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

 December 7, 2006, 05:22 time step for unsteady turbulent flow #1 vishnu Guest   Posts: n/a how to deceide the time step for unsteady turbulent flows. is there any theoritical procedure avialable to calculate the time step. plz help me

 December 7, 2006, 05:29 Re: time step for unsteady turbulent flow #2 bli Guest   Posts: n/a maybe evaluate the time needed for the flow going through the domain and then choose a resolution? but with chemical kinetics or other phenomena (combustion/explosion....)you may think the time scale for that specific phenomenon.

 December 7, 2006, 05:37 Re: time step for unsteady turbulent flow #3 wabik Guest   Posts: n/a Hi, There is also an adaptive time approach to the problem. Instead of fix time step you can use adaptive one ... PW

 December 7, 2006, 05:50 Re: time step for unsteady turbulent flow #4 Emmanuel Guest   Posts: n/a If your flow is periodic, obtain the period ie. 1/frequency, then divide by the number of time steps you want say 100. This will be the value of your "Time Step Size". Example your frequency is 220hz, then you period = 0.00454545s, for 100 time steps, your "Time Step Size" = 4.54545e-5. The value you use for "Number of Time Steps" depends on the number of cycles you want. if you want 5 cycles then you use 5*100=500. You can then use the default value for the rest.

 December 11, 2006, 04:25 Re: time step for unsteady turbulent flow #5 vishnu Guest   Posts: n/a thank you....... is time step depends on the property which we require( for example temerature in turbulent flow or pressure in turbulent flow)?. does it depend on the accuracy of the property which we require?

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post Niklas Wikstrom (Wikstrom) OpenFOAM Running, Solving & CFD 122 June 15, 2014 06:20 bookie56 OpenFOAM Installation 8 August 13, 2011 04:03 sandisk FLUENT 0 July 18, 2011 02:57 Lord Kelvin OpenFOAM 6 April 12, 2011 11:24 panda60 OpenFOAM Bugs 4 July 8, 2010 10:23

All times are GMT -4. The time now is 00:01.