PRESSURE DISTRIBUTION ON A LOW-RISE BUILDING MODEL SUBJECTED TO A FAMILY OF BOUNDARY-LAYERS

In natural environments, terrain roughness over a sizeable area is alm ost always in a random pattern. The roughness elements on the ground, e.g., trees and buildings, usually are not uniform in size, shape, or in the spacing between them. However, simulations conducted in the win d tunnel for such terrain conditions often simplify, if not completely overlook, the random nature of the problem. The randomness is typical ly replaced by a uniform roughness field in which the roughness elemen ts are uniform in size, shape, and spacing. In fact, uniform roughness fields have become a standard tool in wind tunnel simulations. As a r esult, the prototype terrain condition is not modeled geometrically an d the consequences of leaving out randomness in a simulation have not been examined thoroughly. To address this issue, several random roughn ess fields and one uniform roughness field were tested. Boundary layer s generated by these roughness fields as well as the pressure distribu tion on a low-rise building model were recorded. Comparison of the res ulting data showed significant differences between random roughness an d uniform roughness simulations, even though all the boundary layer pr ofiles fell within a single terrain roughness category.