Wind and Structures

Volume 9, Number 6, 2006, pages 419-440

DOI: 10.12989/was.2006.9.6.419

Large-scale quasi-steady modelling of a downburst outflow using a slot jet

W. E. Lin and E. Savory

Abstract

This article synthesizes the literature on the meteorology, experimental simulation, and wind engineering ramifications of intense downburst outflows. A novel design of a large-scale test facility and experimental evidence of its validity are presented. A two-dimensional slot jet is used to simulate only the outflow region of a downburst. Profiles of mean velocity and turbulence quantities are acquired using hot-wire anemometry. Comparison with the literature provides empirical evidence that supports the current approach. A geometric analysis considers the validity of applying a two-dimensional approximation for downburst wind loading of structures. This analysis is applicable to power transmission lines in particular. The slot jet concept can be implemented in a large boundary layer wind tunnel to enable large-scale laboratory experiments of thunderstorm wind loads on structures.

Key Words

downburst outflow; microburst outflow; localized intense wind; thunderstorm wind load; large-scale wind tunnel; two-dimensional wall jet; slot jet; frontal curvature.

Address

Department of Mechanical & Materials Engineering,rnThe University of Western Ontario, London, Ont., Canada, N6A 5B9