3. Numerical Model Set Up
3.1 Building Models and Computational Grids
Hexahedral non-uniform grids are used in all
models. The high resolution grids were applied near
the building walls and at the ground to capture the
development of the flow near the wall surfaces. The
building shapes, grids, and wind direction are shown
in Figure 2. The Phoenics 3.5 commercial package
is used to generate these cells. The two models 3A
and 3B are similar but the wind direction strikes the
36 x 14 m2 facade in Model #3A and the 24 x 14 m2
facade in Model #3B. The domain size, smallest grid
size, total number of cells, turbulence models, differencing
schemes and times spend in running
models# 1, 2, 3A and 3B are shown in Table1. In all
models, x is the direction of the wind. The hybrid
differencing scheme in Phoenics program is the
central-differencing scheme. This validated with
previous work that used the low Reynolds model,
hence Model #1 was simulated using steady low
Reynolds model. The k-ε model, as a widely used
model in engineering studies and the simulation
industry, was simulated to compare their results with