How to model trees?
On this page, a short advice for the numerical modeling of trees is given.
The easiest way of the numerical tree modeling is to assign a pressure loss coefficient λ [Pa (Pa m)-1] to vegetation containing grid cells.
Assume a permeable obstacle of streamwise depth d which fills the entire cross section of a duct (forced convection condition). The pressure loss coefficient λ gives the difference in static pressure Δpstat at the windward and leeward side, normalized by the dynamic pressure pdyn and the obsatclesís streamwise depth d, according to
u mean velocity component in streamwise direction
d obstacle's streamwise depth
pluv static pressure windward of the obstacle
plee static pressure leeward of the obstacle
ρ density of fluid
The pressure loss coefficient λ is a parameter depending on the internal structure of the obstacle and describes integrally the permeability.