The behaviour of gas and fluid flows directly depends on the Reynolds number. When such number is higher than 10, reflow may occur and have an effect on heat transfer, mass transfer or dwell time for example. When the

number of Reynolds is under 2000, the flow is called laminary flow and may be modeled by means of

Navier Stokes equations. Their digital resolution enables to estimate flow structure and pressure distribution. For a Reynolds exceeding 2000, we encounter non-stationary structures, as well as gradually decreasing structures that dissipate part of the energy of the flow referred to as "turbulent". RANS models (Reynolds Average Navier Stokes), such as the "realizable k epsilon" model which includes two additional equations referring to the conservation and the dissipation of the turbulence kinetic energy, provide similar flow representations but involve relatively lower costs and less time. This is why they are widely used in industrial applications and, of course, they are used by INOPRO iao in studies and model optimizations, as they offer a better representation of turbulence.