Question

For integrating the convective and diffusive fluxes using the mean value approximation, the value at the ___________ is used.

(a) face centre

(b) cell centre

(c) node

(d) vertex

The question was posed to me in an online quiz.

This interesting question is from Finite Volume Methods topic in chapter Finite Volume Methods of Computational Fluid Dynamics

Answer 1

The correct choice is (a) face centre

To elaborate: The convective and diffusive fluxes undergo a surface integral. To get the surface integral, they are integrated over the area of the face considered. While approximating using the mean value approximation, the central value is used. So, the value at the face centre is used.