The calculation of low Reynolds number turbulent wall jets

Turbulent cylindrical wall jets at low Re are studied numerically. Attention is focused on a simple turbulence model based on Prandtl's mixing length hypothesis normally used to predict boundary layer flows at high Re. The Re range of interest is below 5000. Continuity and momentum equations are defined, together with boundary conditions and an eddy viscosity term, the latter to relate shear stress to the mean velocity. The governing equations are solved using an implicit forward marching finite difference scheme. A comparison with experimental data reveals overpredictions of the rate of jet spread and local maximum velocities. Neglecting damping effects in the near-wall region improves the accuracy of the turbulence model.