A limited-length-scale κ-ε model for the neutral and stably-stratified atmospheric boundary layer

Analytical and numerical models of the neutral and stably-stratified atmospheric boundary layer are reviewed. Theoretical arguments and computational models suggest that a quasi-steady state is attainable in a boundary layer cooled from below and it is shown how this may be incorporated within a time-steady, one-dimensional model. A new length-scale-limited k- epsilon model is proposed for flows where a global maximum mixing length is imposed by the finite boundary-layer depth or, in stably-stratified conditions, by the Obukhov length, whilst still reducing to a form consistent with the logarithmic law in the surface layer. Simulations compare favourably with data from the Leipzig experiment and from Cardington airfield in England.