Analysis of different RANS models applied to turbulent forced convection

The aim of this work is to study the adequacy of different RANS models in terms of accuracy and numerical performance in the description of turbulent internal forced convection flows. Within RANS modelizations, linear and non-linear eddy-viscosity models and explicit algebraic models are explored. A comparison of the suitability of different two-equation platforms such as k-ϵ and k-ω is also carried out. Three different internal forced convection flows are studied: turbulent plane channel, backward facing step, and confined impinging slot jet. The results are compared with DNS or experimental data available in the literature, reviewing mean and fluctuating velocities, turbulent stresses and global parameters like Nusselt number, skin friction coefficient or reattachment point. Governing partial differential equations are transformed to algebraic ones by a general fully implicit finite-volume method over structured and staggered grids. A segregated SIMPLE-like algorithm is used to solve pressure-velocity fields coupling. A verification procedure based on the generalised Richardson extrapolation is applied to ensure the credibility of the numerical solutions.