Study of Microburst Winds and Their Loading Effects on Built Structures

Iowa State University, Ames IA

Investigators

Abstract

The objective of this project is to conduct a fundamental study to quantify the characteristics of violent microburst winds and their loading effects on ground-based civil structures. A synergistic approach is used in this study that involves laboratory simulations using a translating microburst simulator and scaled models of civil structures, numerical simulations using CFD, and field data for validation of the simulated flow field. Particle Image Velocimetry is used to provide detailed flow-field measurements while existing CFD models are extended to include buoyancy effects to verify the similarities between a natural microburst generated by descending cold air with those generated in laboratory simulations. The characteristics of unsteady flow structures of microburst winds and resultant wind loads on civil structures are investigated in great detail. One of the outcomes of this study will be knowledge of wind-speed profiles of microburst winds in various terrains, and a catalog of aerodynamic loads for typical civil structures that will be useful for future design of such structures. The goal of this project is to elucidate the underlying physics for a better understanding of microburst wind hazard in order to provide more accurate prediction of wind damage potential to built structures with the ultimate goal of reducing the loss of life or injury and economic loss. Society at large will benefit significantly from improved predictions of damage potential of violent near-ground winds and improved building or design codes that can help in mitigating this type of wind hazard. This project will also benefit graduate, undergraduate and K-12 students as well as public in general through improved curricula, laboratory demonstrations, Internet-based disseminations and news media outlets.