What is the SIMPLE algorithm used for in CFD?

What is the SIMPLE algorithm used for in CFD?

• A. It is a pressure-velocity coupling algorithm for steady/semi-implicit incompressible flows that iterates to enforce continuity.
• B. It solves heat conduction in solids.
• C. It models chemical reactions.
• D. It is used for compressible flows with shocks.

Answer: (C)

The main idea is that SIMPLE is a method to couple pressure and velocity in incompressible flow simulations. In incompressible Navier–Stokes, the velocity field must be divergence-free, which links how pressure and velocity influence each other. SIMPLE handles this with a two-step, iterative process: first, solve the momentum equations using a guessed pressure to obtain an intermediate velocity; then derive and solve a pressure correction equation from the continuity equation, update pressure, and adjust the velocity accordingly. Repeating these steps reduces the residuals and enforces continuity, giving a stable solution for steady or semi-implicit time stepping. This algorithm is not about solving heat conduction in solids, chemical reaction kinetics, or compressible flows with shocks. Those require different models or numerical treatments, whereas SIMPLE specifically addresses the pressure–velocity coupling in incompressible (or nearly incompressible) flows.

The main idea is that SIMPLE is a method to couple pressure and velocity in incompressible flow simulations. In incompressible Navier–Stokes, the velocity field must be divergence-free, which links how pressure and velocity influence each other. SIMPLE handles this with a two-step, iterative process: first, solve the momentum equations using a guessed pressure to obtain an intermediate velocity; then derive and solve a pressure correction equation from the continuity equation, update pressure, and adjust the velocity accordingly. Repeating these steps reduces the residuals and enforces continuity, giving a stable solution for steady or semi-implicit time stepping.

This algorithm is not about solving heat conduction in solids, chemical reaction kinetics, or compressible flows with shocks. Those require different models or numerical treatments, whereas SIMPLE specifically addresses the pressure–velocity coupling in incompressible (or nearly incompressible) flows.