RANS canopy constants from weak turbulence regime

Abstract

A Taylor series expansion was used to model the effect of forest canopies in the k - ε RaNS model transport equation for the turbulent kinetic energy. The model assumes that the turbulent kinetic energy is smaller than the kinetic energy of the mean flow (weak turbulence regime). Comparisons with large eddy simulations showed that a second-order approximation is able to account for 80% of the total canopy effect, while including third- and forth-order terms increases this value to 98.