ABSTRACT
The three-dimensional, time-dependent Navier-Stokes equation, written in generalized coordinates, and the Smagorinsky eddy viscosity subgrid are used for simulating wind distribution over complex terrain with windbreak. The models can be used to determine the windbreak location most suitable for preventing wind erosion. Two cases are given, and effects of windbreaks on the prevention of wind erosion are discussed. One case used a 2 meter high windbreak hedge for preventing sand from shifting around a barchan sand dune, which is 5 m high, 64 m wide, and 96 m long. The simulation results show that the best place for the windbreak is 18 m to 22 m in front of the top of the sand dune. Another case used terrace construction and a 2 m high windbreak hedge for reducing wind speed over an idealized hill, which is 20 m high and 320 m long. The simulation results show that terrace construction could reduce over 40% of wind speed on the windward side and that the windbreak hedge at the terrace edge could reduce a further 20% of wind speed on most of the windward side. However, there would be an overspeeding region appearing at the two side slopes of the hill.
