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Wind Farm Flow Simulation 2

Posted October 6, 2016 at 11:12 by windsimu

I calculated the courant no.

The maximum velocity is approximately 18m/s at the top. and if the time step is 0.15s, the courant no. is 1.08 (dx = 2.5m). So the time step indeed should be decreased. But the time step in the last step is 0.015s, the courant no. is 0.108. It is pretty small. So I slightly increased the time step to 0.05s. I got 1000s physical time after 1 day, so I expect I can get 300-400s physical time after 1 day running.
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Wind Farm Flow Simulation 1

Posted October 6, 2016 at 10:43 by windsimu

I run a simulation case from NREL in OpenFOAM 2.1.1 (3km*3km*1km). I would like to use this case and solver (ABLSolver) to simulate the flow field in wind farm. I refined a region for wind turbine in this case (detx=2.5m).

The case works pretty well before 3035s. From 3035s, the max courant no. increased instantly from 0.75 to 2.6e+25. I used adaptive time step and the maximum time step is set to be 0.5 (it is normally 0.15 because of max courant no.) and maximum courant no. is 0.75....
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Hello All

Posted September 18, 2016 at 15:43 by KTW310

Hi, my name is Keith Wilkins and I am a student at Temple University in Philadelphia, PA. I am studying Mechanical Engineering and just started taking a CFD course a few weeks ago. I graduate this upcoming December and expect to be continuing education in Fall 2017 for a masters, whether it will be in Mechanical or Electrical Engineering is yet to be decided.

So far CFD is very interesting and I am excited to learn more about it so I can use it for my senior design project. I am working...
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Dual-Booting : win7 & linux-mint

Posted August 28, 2016 at 18:50 by kindle
Updated June 7, 2017 at 12:20 by kindle (clarity)

Installation from nothing : First win7 then linux-mint.
Win7 writes in MBR something to control boot and linux uses grub to control boot which will be able to boot windows.
Why not in the reverse order?
A complete re-installtion of win7 may over write ALL in MBR meaning the part that will call the actual grub configuration (in /boot or /etc/grub.d not sure...), therefore the repair of the linux booting is needed.
Result: grub boot first, if you choose "windows"...
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Numerics in OpenFoam - PBiCG vs. PCG

Posted August 18, 2016 at 14:13 by kindle
Updated February 23, 2017 at 04:13 by kindle

So the numerical scheme (fvScheme) will affect the property of the matrix to invert and we should choose properly the solver/solving algorithm (fvSolution) in order to solve it properly. Depending on the form of matrix depended on structured or unstructured mesh something like that.

Originally Posted by thg View Post
Hi Frog,

Meindert already mentioned, the difference between a PCG or a PBiCG,...
you can find in any textbook about linear iterative solvers like
Wessling, Saad, Trefethen, Stran,....
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