A method for rapidly computing windbreak flow field variables

•Presents a windbreak design tool.•Model for rapid and routine estimations of the impact of windbreaks on flow fields.•Mean velocity and turbulence stress field estimates for windbreaks of optical porosity from 0 to 0.7.•Model applicable to single row windbreaks, neutral atmospheric stability and orthogonal winds.

Computationally inexpensive numerical models for determining components of the mean and fluctuating velocity fields through and around windbreaks are developed for fast and routine calculations such as the estimation of the impact of windbreaks in land management applications. The mean velocity model utilizes the previously-developed QUIC Dispersion Modeling System platform and methodology, which relies on empirical parameterizations together with the principle of mass-conservation to achieve results that are comparable to traditional computational fluid dynamics models, but with far less computational cost. The fluctuating velocity field is an implementation of a similarity solution presented previously. Both the mean and fluctuating velocity models are applicable upwind and downwind of windbreaks having varying thicknesses and optical porosities. Simulations of both wind tunnel and field study experiments show excellent agreement with the data for windbreaks of varying optical porosity (0–0.7) and upstream roughness (1/301/30–1/6001/600 of windbreak height). Results are presented for windbreaks composed of a single row, under neutral atmospheric stratification, and subject to orthogonal winds.