Field Tests on a Full-Scale Steel Chimney Subjected to Vortex-Induced Vibrations

Abstract

Industrial chimneys, launch vehicles and stacks are examples of large diameter circular cross section structures which can be prone to cross-wind vortex-induced vibrations. VIV has been extensively studied for both fundamental and applied issues, but few documented studies concern high Reynolds number regime (> 5•10 5 ) in atmospheric turbulent wind. This paper introduces a field test on a slender light and low damped chimney designed to experience "supercritical" VIV at moderate wind velocity. The chimney was recently erected in a wind monitored field, near the Atlantic coast of France. The purpose of this paper is to present the first vibration results obtained during a sequential 13-days period in September 2020. A statistical analysis has been performed on the amplitude and dominant frequency responses and results are reported in term of probability distribution as a function of wind speed and direction. VIV events of low (< 15 % of diameter) to moderate amplitude (> 30 % of diameter) have been highlighted in a range of wind velocity 25 % lower than expected, along with significant influence of the wind direction. Low turbulent easterly wind giving vortex-induced vibrations with the highest amplitude.

Twin Strouhal numbers in pressure loading of circular cylinder at high Reynolds numbers

“…From these data, it turns out obvious that wind tunnel tests have to be made at the right Reynolds number which is encountered in the application. For instance in wind engineering (Lupi et al 2017;Ellingsen et al 2021), industrial chimneys have typically a diameter of 2 m and a natural first bending frequency of the order of 1 Hz. Then the critical wind velocity at which the resonance occurs with the alternate vortex shedding is in the range 7.5-10 m/s.…”

Frequency Analysis of Steel Chimneys Using the Finite Element Method

“…Through computation of the modal, selfvibration, and wind vibration frequency, it was confirmed that the steel chimney can lessen the influence of the wind load on the chimney and flange connection. Thus, developed a technique forincreasing the chimney'sstructural strength and effective in reducingthe resonant frequency under wind load.Ellingsen et al [3] carried out a full-scale field test on slender, low-damped light weight steel chimney.The initial vibration data was collected for consecutive 13days period. Further, a statistical study was carried out and his amplitude and dominant frequency responses were shown as a function of wind speed and direction in terms of the probability distribution.…”