Loading…

Experimental evidence of the wind-induced bias of precipitation gauges using particle image velocimetry and particle tracking in the wind tunnel

•Wind tunnel experiments over three precipitation gauges with different outer shape.•Imaging technique to capture drop trajectory deviations above the gauge collector.•PIV measurement of the airflow pattern above precipitation gauges. Wind tunnel (WT) experiments were conducted to reproduce the wind...

Full description

Saved in:
Bibliographic Details
Published in:Journal of hydrology (Amsterdam) 2021-09, Vol.600, p.126690, Article 126690
Main Authors: Cauteruccio, Arianna, Brambilla, Elia, Stagnaro, Mattia, Lanza, Luca G., Rocchi, Daniele
Format: Article
Language:English
Subjects:
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•Wind tunnel experiments over three precipitation gauges with different outer shape.•Imaging technique to capture drop trajectory deviations above the gauge collector.•PIV measurement of the airflow pattern above precipitation gauges. Wind tunnel (WT) experiments were conducted to reproduce the wind-induced deviation of rain drop trajectories when approaching the collector of catching-type gauges. Three typical outer shapes of the instrument body (cylindrical, inverted-conical and “chimney” shapes) were tested using full-scale models. The airflow pattern upstream of and above the collector was measured with a Particle Image Velocimetry technique, after injecting a passive tracer in the flow. Tests were performed by releasing water drops in the WT flow to mimic the raindrops fall. The drop trajectories near the gauge collector were tracked and quantitatively measured using a high-speed camera. The deviation of the trajectories, induced by the bluff-body aerodynamics of the gauge, is interpreted here by comparing the measured airflow pattern around the three instruments to highlight the effect of their different outer shapes. The “chimney” shape, that is typical of some weighing type gauges, demonstrated lower performance with respect to the cylindrical and inverted-conical shape, showing the most relevant effect in deviating the trajectories of the approaching drops when immersed in a wind field.
ISSN:0022-1694
1879-2707
DOI:10.1016/j.jhydrol.2021.126690