fluent error for gases diffusion and reaction

chen

hello all,

I have some queations for simulating gases diffusion and reactions. My model is three velocity inlets,has three differient gases and velocity, and react in the model.

These are my quastions: (1)Sometimes, fluent had error when i ran some iterations.

Error: Gauss_Elimination: singular matrix.

Error Object: ()

(2)when i smooth/swap my mesh, fluent said

"moved 39 nodes, unable to move 2 nodes, most skewness improvement 0.195417, 3 remaining iterations.

moved 39 nodes, unable to move 2 nodes, most skewness improvement 0.108514, 2 remaining iterations.

moved 35 nodes, unable to move 3 nodes, most skewness improvement 0.031693, 1 remaining iterations.

moved 35 nodes, unable to move 3 nodes, most skewness improvement 0.033279, 0 remaining" iterations.

anyone know what happen?

Thanks!