# Algebraic Multi-Grid Method

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December 11, 2018, 13:39
Algebraic Multi-Grid Method
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Hi all,

the fixed cycles in AMG method moves according to
1) Pre-relaxation sweeps, β1
2) Multigrid cycle β2, and
3) post-sweeps β3

where to define β2?

Thanks
Attached Images
 scalar.png (26.0 KB, 43 views)

 December 11, 2018, 13:59 #2 Senior Member   Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,145 Rep Power: 61 Just above your red box you choose the cycle type (V/W/F) and the termination criteria.

December 11, 2018, 14:12
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Quote:
 Originally Posted by LuckyTran Just above your red box you choose the cycle type (V/W/F) and the termination criteria.
Dear, that is termination criteria and is for flexible cycle.

The error on the coarse grid is reduced by performing a specified number β2 of multigrid cycles (represented in Figures 25.6.1 and 25.6.2 as squares). Commonly, for fixed multigrid strategies β2 is either 1 or 2, corresponding to V-cycle and W-cycle multigrid, respectively.
https://www.sharcnet.ca/Software/Flu...g/node1009.htm

 December 11, 2018, 14:35 #4 Senior Member   Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,145 Rep Power: 61 For flex cycles there's termination and restriction criteria. For fixed cycles, there's termination criteria. If you click the box under cycle you will find V/F/W or Flex cycles. Just pick one. The B2 is not a parameter you can change. B2=1 means V cycle. B2=2 means W cycle. B2=3,4,5, etc is not implemented. In your screenshot, you can see Y-momentum Flex. Click that flex box and you can change to a fixed cycle. m.uzair likes this.

 December 11, 2018, 15:12 #5 Member   Muhammad Ali Uzair Join Date: Sep 2017 Posts: 44 Rep Power: 7 Thank you dear for the clarification.

 Tags algebraic multi-grid, amg, eulerian multiphase model, fluent