In computational fluid dynamics (CFD), SIMPLE algorithm is a widely used numerical procedure to solve the Navier-Stokes equations. SIMPLE is an acronym for Semi-Implicit Method for Pressure Linked Equations.

The SIMPLE algorithm was developed by Prof. Brian Spalding and his student Suhas Patankar at Imperial College, London in the early 1970s. Since then it has been extensively used by many researchers to solve different kinds of fluid flow and heat transfer problems.[1][2]

Many popular books on computational fluid dynamics discuss the SIMPLE algorithm in detail.[3][4] A modified variant is the SIMPLER algorithm (SIMPLE Revised), that was introduced by Patankar in 1979.[5]