Question

For which of these schemes is the interpolation profile need not be modified for the non-uniform transient grid?

(a) Downwind scheme

(b) Upwind scheme

(c) Crank-Nicolson scheme

(d) second-order schemes

I had been asked this question in an interview.

My doubt is from Approaches for Non-uniform Time Steps in chapter Transient Flows of Computational Fluid Dynamics

Answer 1

The correct option is (c) Crank-Nicolson scheme

To explain: For all the second-order schemes, the interpolation profile has to be modified when the transient grid is non-uniform. But this is not the case when the Crank-Nicolson scheme is used. There is no change in the interpolation profile needed here.