Wind tunnel modelling of the pedestrian wind environment : modelling the built environment

Abstract

This thesis demonstrates that the model of the built environment requires more attention than has been given to it in the past. It examines the ways in which the built environment is modelled in a wind tunnel. Ten factors were identified which influence the design, construction and use of the building model, and have the potential to affect results of wind tunnel tests. These factors were examined systematically, and a commentary provided on the possible effects of each factor. A test process was formulated, and the factor of modelling detail was selected for an in-depth study to determine the usability of the process. This study shows clearly that factors like this one can have a significant impact on results. From the process used to study the factor of modelling detail, a general test process was proposed. This general test is intended to provide a method for examining any aspect of the building model as used in a wind tunnel test of the pedestrian wind environment. The benefits of such a general test process are that all of the factors identified which may have an impact on results can be examined in a systematic fashion, and changes made to current practice, where necessary. A further use of the general test process proposed is in evaluation of wind tunnel performance. If the same set of tests is carried out in a number of wind tunnels, the difference between the performance of each can be established. As the test process includes a comparison of wind tunnel results with full scale conditions, the reliability of the wind tunnel representation of reality can be established. This general test process has not been implemented in this study, but is a suggested approach for further research into the effects of modelling factors on test results. Other lines of research identified include an examination of how the factors interrelate; and the influence on test results of the way the test is performed.