I am totally new to freefem++ and trying to solve 4 PDEs in 2D. My problem is the system is unstable and can not converge I use Problem statement. I am not sure I should move to stabilization techniques or PETSc
when I change the variational form writing from problem to varf the solution is not correct at all even at the first steps.
I attached my code and also copy and paste the two ways I am trying to write the variational form with (problem , varf ) stament
My questions are
1- why when I change from problem to varf the results is changed
2- should I use PETSc or move to stabilization techniques like SUPG or artificial diffusion
Dear All,
I am totally new to freefem++ and trying to solve 4 PDEs in 2D. My problem is the system is unstable and can not converge I use Problem statement. I am not sure I should move to stabilization techniques or PETSc when I change the variational form writing from problem to varf the solution is not correct at all even at the first steps. I attached my code and also copy and paste the two ways I am trying to write the variational form with (problem , varf ) stament
My questions are 1- why when I change from problem to varf the results is changed 2- should I use PETSc or move to stabilization techniques like SUPG or artificial diffusion
problem HydrodynamicNe(Ne, v1) = int2d(Th)(Nev1 +(Dedt(grad(Ne)'grad(v1)) +(-Wex dx(Ne) + -Wey dy(Ne))dtv1)) -int2d(Th)(Neoldv1) -int2d(Th)(Sev1dt)
+int1d(Th,needle)(gammaNpoldmupEmagv1dt)
;
varf HydrodynamicNe(Ne, v1) = int2d(Th)(Nev1 +(Dedt(grad(Ne)'grad(v1)) +(-Wex dx(Ne) + -Wey dy(Ne))dtv1)) -int2d(Th)(Neoldv1) +int2d(Th)(Sev1dt)
+int1d(Th,needle)(gammaNpoldmupEmagv1dt)
; matrix AE = HydrodynamicNe(Ve,Ve) ; real [int] bE = HydrodynamicNe(0 ,Ve) ;
trail 1.log