Question

Which of these statements is correct about the transient SIMPLE algorithm?

(a) No additional terms are needed in the continuity and pressure-correction equations

(b) No additional terms are needed in the continuity equation

(c) An additional term is needed in the continuity and pressure-correction equations

(d) No additional terms are needed in the pressure-correction equation

This question was addressed to me in a job interview.

This intriguing question originated from Transient SIMPLE and PISO Algorithms in section Transient Flows of Computational Fluid Dynamics

Answer 1

Right choice is (c) An additional term is needed in the continuity and pressure-correction equations

The explanation is: The transient (unsteady) terms are added to the continuity equation. As the transient SIMPLE algorithm derives its pressure-correction equation from the continuity equation, the pressure-correction equation also gets some additional terms.