Question

The flow variable at the vertex node is calculated using the weighted average of the values at the cells sharing it. What is the weight used here?

(a) Inverse of the distance of the vertex from the cell centroid

(b) Distance of the vertex from the cell

(c) Centroids of the cells

(d) Mass of the cells

This question was posed to me in homework.

The origin of the question is Diffusion Problem topic in section Diffusion Problem of Computational Fluid Dynamics

Answer 1

The correct choice is (d) Mass of the cells

The best explanation: The impact decreases as the centroid of the cell moves away from the vertex. So, the inverse is used as the weight here. This is why the method needs an enlarged stencil. But it leads to more accurate approximation.