An equation that is common to all the CFD for Fluidized Bed Reactor equations is the Navier-stokes equation. This equation defines any single phase of fluid flow. To get Euler equations, the Navier-stokes equation can be simplified by removing the terms describing viscosity. It therefore means that CFD for fluidized bed reactor equations stem from the Euler equation. The methods used in these equations were first developed to help solve the linearised potential equations. However with the development of computer power the equations were able to be transformed to develop three dimensional methods. This is what formed the basic parts of the CFD for fluidized bed reactor equations.