A quasi-steady model to account for the effects of upstream turbulence characteristics on pressure fluctuations on a low-rise building

Abstract

The effects of upstream turbulence on roof pressure fluctuations of a low-rise building are investigated via the quasi-steady (QS) vector model. Atmospheric boundary layer (ABL) turbulence, with intensities ranging from 13% to 27% and integral length scales from 6 to 13 times the building height, is simulated in a boundary layer wind tunnel. The model building surface pressures are measured synchronously with the velocity at a point one building height above the leading edge. The QS model is found to accurately explain the effects of the ABL turbulence with scales larger than about 5 building heights. Furthermore, a QS model established in one terrain can explain the pressure fluctuations in the other terrains based on the fact that the model functions are similar over the range of observed upstream terrain conditions. This finding is important to the Partial Turbulence Simulation approach since there may be a range of turbulence intensity – integral scale combinations which can yield the same aerodynamic behavior, allowing more flexibility for choosing the model length scales. However, further work is required for modelling the effects of small-scale turbulence on the peak pressures and in defining appropriate bounds when the precise turbulence simulation can be relaxed.