A note on the numerical treatment of the k-epsilon turbulence model

Numerical solution of the equations arising from the kappa - epsilon turbul ence model has difficulties inherent to nonlinear convection-reaction-diffu sion equations with strong reaction terms, resulting in that numerical sche mes easily became unstable. We present a formulation that stresses on the r obustness of the solution method, tackling common problems that produce ins tability. The main contribution concerns the loss of positivity of kappa an d epsilon, which is addressed by acting on the coefficients of the reaction and diffusion terms rather than on the turbulent variables themselves. In addition, a linearized implicit, non-iterative, treatment of the wall law i s proposed.