Laplace value in freefem

General Discussion
1

Dear all

I have the values for (Ux,Ur,Utheta) and I want to calculate ((1/Re)Laplace(U)) for axisymmetric geometry. because of having y^2 as the denominator, its calculation is difficult. I wanted to use the following
varf Laplace(unused,[wx,wr,wphi])=
int2d(th)(2pi(1/Re)y(D(U).D(w)));

Xh A=Laplace(0,Xh);

where D=0.5*(Grad(U)+GradT(U))

but I had error.

how I can drive it?

2

Can you replace 1/y terms in D(U) with 1/(y +(y==0)) to remove the pole and let your BCs on the central axis handle the rest?