Date of Award
Doctor of Philosophy
Simulation methods have recently emerged as the most reliable, and in some cases, the only means available for predicting design wind speeds in tropical cyclone-prone regions of the world. This thesis presents a refined simulation procedure. The windfield model is considerably more complex than those used in previous simulations. Wind speeds and directions are defined at three levels, (i) at the 700 mb height, where gradient balance is assumed to apply, (ii) at the 500 metre height, where surface friction and translation of the storm system itself combine to modify the circulation in a manner which, in the current simulation, is computed using a recently developed numerical hurricane boundary layer model, and (iii) at the surface or 10 metre height. Within the windfield model, the boundary layer variation of wind speed and direction and the influences on the three circulation levels when landfall is made are defined using data gathered in recently occurring tropical cyclones. The simulation also contains a new filling model taking into account the geographical variation of this phenomenon along the U.S. coastline.;The simulation windfield model is evaluated by comparing actual wind records obtained in recently occurring tropical cyclones with wind speeds and directions predicted by the model itself. The storms chosen for these comparisons include North Atlantic, Northwest Pacific and Australian tropical cyclones. The statistical representation of the tropical cyclone characteristic parameters required in the simulation is reviewed and in some cases new distributions have been proposed. The description of these climatological parameters has application in fields other than the prediction of design wind speeds.;The simulation procedure was applied to the Gulf and Atlantic Coasts of the United States to yield extreme wind speed estimates. The results show significant variation along the coastline and compare reasonably with two recent studies of U.S. hurricane design wind speeds.;Finally, the simulation procedure is extended to handle the increased risk sustained by line-like structures, such as transmission lines, and to be compatible with the methodology currently used in the calculation of structural response exceedances, basic to the prediction of wind-induced building response.
Georgiou, Peter Nicholas, "Design Wind Speeds In Tropical Cyclone-prone Regions" (1986). Digitized Theses. 1523.