Model scale effect of topography on wind tunnel testing for buildings

Abstract

This paper presents a discussion concerning the wind tunnel testing technique and the extent of proximity for the scaled topography required in model studies for wind effects on buildings and urban environment. This discussion is based on several literature reviews which concluded with sufficient evidence that increasingly significant errors occur in modelling of flow conditions when the geometric model scales are reduced below 1/500. Thus it is inadequate, if not impossible, to use a separate small topographical (1/2500 or smaller) scale model study to determine the wind profile characteristics due to the wide far-field area of terrain for a much larger scale model study of wind effects. The discrepancy of these model measurements using wind profiles matching from a separate small scale topographical study as compared to an extensive 1/400 scale model study in a large wind tunnel working section is illustrated