Fluid flow and heat transfer in a pipe with wall suction

Abstract

The effects of wall suction on turbulent fluid flow and heat transfer in a pipe were numerically studied using the Reynolds-averaged Navier-Stokes equations in conjunction with the temperature equation. Linear and non-linear κ-ε or κ-ω low-Re models of turbulence are used for ‘closing’ the governing equations. Computed mean velocity and temperature profiles were compared with analytical solutions and experimental measurements for suction rates between 0.46 and 2.53%. Analytical results, based on boundary layer assumptions and mixing length concepts, were found to be in satisfactory agreement with computed and experimental data for the lowest suction rate examined. However, for the highest rate, they did not follow the computed and experimental ones, especially in the near-wall region. Near-wall velocities and temperatures increased with increasing suction rate. Computed and experimental velocities and temperatures fell below the corresponding logarithmic law of the wall with no suction. Computed and experimental turbulent shear stress and heat flux were reduced by the presence of wall suction. The excess skin friction coefficient and Nusselt number, resulting from suction, were found to be up to 9 times the respective ones with no suction.