Question

The pressure used to find the velocities from the momentum equations is of __________

(a) the previous time step

(b) the oldest value

(c) the latest value

(d) the current time step

The question was asked during an internship interview.

I'd like to ask this question from Incompressible Flows topic in portion Incompressible Flows & Compressible Flows of Computational Fluid Dynamics

Answer 1

The correct answer is:

(a) The previous time step

In numerical methods for solving fluid dynamics equations, particularly when using schemes like the SIMPLE algorithm for incompressible flows, the pressure used to compute the velocities in the momentum equations is typically taken from the previous time step. This is because, at each time step, the velocities and pressures are updated iteratively, and the velocity fields depend on the previous pressure field. This iterative process ensures the pressure-velocity coupling is resolved.