ANALYZING WIND-DRIVEN RAIN ON A BUILDING FACADE USING THE LASER PRECIPITATION MONITOR (LPM)

This paper is concerned with a building situated in the west of Scotland which faces severe weatherconditions with high wind speeds and driving rain occurring frequently. This results in extensivedamage to the building fabric, and affects the internal climate which leads to a serious issue in buildingconstruction. In this study, a three-dimensional numerical model of airflow around the building isinvestigated. This investigation is part of ongoing research on wind-driven rain which has establishedthe importance of moisture stresses, wind flow and rain impacts on a commercial building. The fullscale experimental facility which includes anemometers, rain gauge, driving rain gauges and sensors isdescribed. To supplement this, a sophisticated laser precipitation monitor (disdrometer) was installed,which collects rain data every 1-minute. This provides accurate measurement of drop size and speed ofthe falling raindrops which plays an important role in wind-driven rain studies.Comparisons with numerical simulations and experimental data were predicted. Results shows that theaverage predominantly wind direction for the sample test period is from south-west (2230 from north)and the driving rain during this period is 86.8 mm for the west facing faade and 193.4 mm for the southfacade. From the computational fluid dynamics (CFD) simulations, it is predicted that the change invelocity profile along the laser strip is due to the test building and the disdrometer head itself, whichultimately affects the driving rain calculations.