Question

The face-based stencil used for computing Φf in the Green-Gauss Gradient formula is ________

(a) more accurate and needs a large stencil

(b) less accurate and needs a large stencil

(c) more accurate and needs a compact stencil

(d) less accurate and needs a compact stencil

This question was addressed to me in my homework.

My question is based upon Diffusion Problem in portion Diffusion Problem of Computational Fluid Dynamics

Answer 1

Right choice is (d) less accurate and needs a compact stencil

To explain: The face-based computation of Φf uses a compact stencil involving face neighbours. This is less accurate than the vertex-based computation involving a large stencil of vertex neighbours.