Question

Which of these statements is correct about the variable time-steps?

(a) The finite volume and finite difference schemes do not yield equivalent algebraic equations

(b) The finite volume scheme yields equivalent algebraic equations irrespective of the non-uniformity

(c) The finite difference scheme yields equivalent algebraic equations irrespective of the non-uniformity

(d) All the second-order schemes result in the same algebraic equation when the grid is non-uniform

The question was posed to me during an interview.

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

Answer 1

The correct choice is (a) The finite volume and finite difference schemes do not yield equivalent algebraic equations

Best explanation: The finite volume and finite difference schemes yield equivalent algebraic equations when the transient grid is uniform. If the grid is non-uniform, the algebraic equations are not the same.