Effect of surface roughness on large-scale downburst-like impinging jets

Author:

Canepa Federico12ORCID,Burlando Massimiliano1ORCID,Romanic Djordje23ORCID,Hangan Horia24

Affiliation:

1. Department of Civil, Chemical and Environmental Engineering (DICCA), Polytechnic School, University of Genoa 1 , Via Montallegro 1, 16145 Genoa, Italy

2. Wind Engineering, Energy and Environment (WindEEE) Research Institute, Western University 2 , 2535 Advanced Avenue, London, Ontario N6M 0E2, Canada

3. Department of Atmospheric and Oceanic Sciences, Faculty of Science, McGill University 3 , Burnside Hall, 805 Sherbrook Street West, Montreal, Quebec H3A 0B9, Canada

4. Faculty of Engineering and Applied Science, Ontario Tech University 4 , 2000 Simcoe Street North, Oshawa, Ontario L1G 0C5, Canada

Abstract

Downbursts are cold descending winds that develop from thunderstorm clouds and, after impingement on the ground, produce an intense low-level horizontal front characterized by an axisymmetric toroidal vortex structure. Surface roughness is a key factor in the characterization of mean and turbulent wind speed features of synoptic-scale stationary atmospheric boundary layer winds. The goal of the present research is to physically assess whether the same can apply to the surface layer produced during thunderstorms, which are non-stationary, highly time-transient, and spatially limited phenomena. Downburst-like flows were produced through the impinging jet technique at the WindEEE Dome, at Western University in Canada. Three different surfaces were tested, and an equivalent full-scale roughness length (z0,eq) was determined. Experimental records are made publicly available. The large geometric and kinematic scales produced high Reynolds numbers, which enabled us to classify the flow as “fully turbulent” and therefore representative of full-scale downbursts. Results indicate a weak dependency on the Reynolds number, which suggests no relevant flaws in extending the results to the natural environment. The overall wind speed maxima weakly depend on z0, whereas a sharp velocity decrease is observed beyond the radial position of the maxima with increasing z0. Surface roughness enhances the boundary layer separation and consequently elevates the height of maximum wind speed above the surface. Vertical profiles of the horizontal velocity return a quite clear nose shape. Turbulence intensity shows a C-like shape with maxima in the near proximity of the ground that increase with z0.

Funder

HORIZON EUROPE European Research Council

Canada Foundation for Innovation

European Union Next-Generation EU

Publisher

AIP Publishing

Reference32 articles.

1. Turbulence characterization of downbursts using LES;J. Wind Eng. Ind. Aerodyn.,2015

2. Thunderstorm structure and circulation;J. Meteorol.,1948

3. Experimental investigation of the near-surface flow dynamics in downburst-like impinging jets immersed in ABL-like winds;Atmosphere,2022

4. Canepa, F., Burlando, M., and Repetto, M. P. (2023a), “Thunderstorm outflows in the Mediterranean Sea area,” Zenodo. https://doi.org/10.5281/zenodo.7495115

5. Canepa, F., Burlando, M., Romanic, D., and Hangan, H. (2024), “Experimental measurements of the effects of surface roughness on large-scale downburst-like impinging jets at the WindEEE Dome laboratory,” Zenodo. https://doi.org/10.5281/zenodo.10686950

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3