difference between solveSegregated and solveCoupled

yfjok22 · May 23, 2014, 05:56

Hi, foamers, I'm new here. These days, I have been reading the class of fvmatrix, and met a small problem: what is the difference between solveSegregated and solveCoupled?
I can see from the code that solveSegregated method stands for solving the vector equation separately, like Ux, Uy, Uz each at one time. But what does solveCoupled mean, does it mean we solve the Ux, Uy, Uz together with a big block matrix A or just solve Ux, Uy, Uz each at one time with the same matrix A?
I really can't figure it out through the code, can any kind friend help me with this?

chengdi · December 23, 2017, 21:49

I think it uses a totally different set of solvers. You can see there are two classes: lduMatrix and LduMatrix<DType,LUType>. Pls note the uppercased initial letter.

And in solveCoupled(), it will construct a LduMatrix, and invoke the solver in it.

The solver in LdUMatrix is also different, like `PBiCCCG`, which is not applicable in lduMatrix.

May 23, 2014, 05:56	difference between solveSegregated and solveCoupled	#1
yfjok22 New Member Fujiang Yu Join Date: Jan 2014 Posts: 12 Rep Power: 12	Hi, foamers, I'm new here. These days, I have been reading the class of fvmatrix, and met a small problem: what is the difference between solveSegregated and solveCoupled? I can see from the code that solveSegregated method stands for solving the vector equation separately, like Ux, Uy, Uz each at one time. But what does solveCoupled mean, does it mean we solve the Ux, Uy, Uz together with a big block matrix A or just solve Ux, Uy, Uz each at one time with the same matrix A? I really can't figure it out through the code, can any kind friend help me with this?

December 23, 2017, 21:49		#2
chengdi Member Di Cheng Join Date: May 2010 Location: Beijing, China Posts: 47 Rep Power: 15	I think it uses a totally different set of solvers. You can see there are two classes: lduMatrix and LduMatrix<DType,LUType>. Pls note the uppercased initial letter. And in solveCoupled(), it will construct a LduMatrix, and invoke the solver in it. The solver in LdUMatrix is also different, like `PBiCCCG`, which is not applicable in lduMatrix.