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Time step for wind turbine analysis

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Old   March 23, 2011, 17:30
Question Time step for wind turbine analysis
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Amool A Raina
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Hi all,
I am using a unsteady density based implicit solver for simulating the flow around a 50m radius wind turbine blade. The turbine rotates at 14 rpm. I would like to know if there is a specific way by which I could determine the time step size for my simulation. I started off with a low time step size 10^-5 and based on the convergence behavior, I kept increasing the size of the time step to 0.01. how do i know of the most appropriate time step size?
Any help would be greatly appreciated!
Thanks,
aar
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Old   March 24, 2011, 01:22
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Raashid Baig
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Quote:
Originally Posted by amoolraina View Post
Hi all,
I am using a unsteady density based implicit solver for simulating the flow around a 50m radius wind turbine blade. The turbine rotates at 14 rpm. I would like to know if there is a specific way by which I could determine the time step size for my simulation. I started off with a low time step size 10^-5 and based on the convergence behavior, I kept increasing the size of the time step to 0.01. how do i know of the most appropriate time step size?
Any help would be greatly appreciated!
Thanks,
aar
Hi Everyone,
I have this doubt too about the automatic timestep (how is it calculated)
and physical time step (how it is calculated) and what is the difference between the physical and auto time scale.
Raashid
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Old   March 24, 2011, 10:29
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Quote:
Originally Posted by amoolraina View Post
Hi all,
I am using a unsteady density based implicit solver for simulating the flow around a 50m radius wind turbine blade. The turbine rotates at 14 rpm. I would like to know if there is a specific way by which I could determine the time step size for my simulation. I started off with a low time step size 10^-5 and based on the convergence behavior, I kept increasing the size of the time step to 0.01. how do i know of the most appropriate time step size?
Any help would be greatly appreciated!
Thanks,
aar
You have to give a look at some paper about experimental studies in wind gallery.From these papers you could get info about the Strouhal and from the Strouhal obtain the eddies relase frequency and form that obtain the period (inverse).Then you have to consider a time step about 100 times inferior to that period.
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Old   March 24, 2011, 14:28
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Amool A Raina
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do u have any references for wind turbines?
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Old   March 25, 2011, 03:58
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Try this : http://www.greenenergywindturbine.co...awt/760131.pdf
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