A Note on k -  Modelling of Vegetation Canopy Air-Flows

Author: Sanz C.  

Publisher: Springer Publishing Company

ISSN: 0006-8314

Source: Boundary-Layer Meteorology, Vol.108, Iss.1, 2003-07, pp. : 191-197

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Abstract

The k -  turbulence model is a standard of computational software packages for engineering, yet its application to canopy turbulence has not received comparable attention. This is probably due to the additional source (and/or sink) terms, whose parameterization remained uncertain. This model must include source terms for both turbulent kinetic energy (k) and the viscous dissipation rate (), to account for vegetation wake turbulence budget. In this note, we show how Kolmogorov's relation allows for an analytical solution to be calculated within the portion of a dense and homogeneous canopy where the mixing length does not vary. By substitution within model equations, this solution allows for a set of constraints on source term model coefficients to be derived. Those constraints should meet both Reynolds averaged Navier–Stokes equations and large-eddy simulation sub-grid scale turbulence modelling requirements. Although originating from within a limited portion of the canopy, the predicted coefficients values must be valid elsewhere in order to make the model capable of predicting the whole canopy-layer flow with a single set of constants.