Experimental study of water spray dispersion around a surface-mounted cube in atmospheric boundary layer flow

Abstract

Processes of spray dispersion around bluff bodies in wind are central to many engineering applications; notably the design of wildfire sprinkler systems and spray cooling systems for urban areas. Simulation methods such as computational fluid dynamics (CFD) have been widely used for the prediction and analysis of such wind-body-spray interactions. However, there has been a lack of high-quality experimental data against which simulations can be validated. In this study, detailed outdoor experiments were performed on the dispersion of water sprays near an isolated 2.4 m cube mounted on the ground and immersed in the atmospheric boundary layer. Sixteen experiments were conducted, each with either a butterfly or hollow-cone sprinkler implemented on the windward or leeward side of the cube. The deposition of water was measured on the cube surfaces and ground, and high-frequency air velocity measurements were taken at three heights to characterise the atmospheric boundary layer flow. Separate experiments were conducted in a test enclosure using a high-speed videography technique to measure the spatial and temporal distributions of mass flow rate, droplet size, and droplet velocity within each spray. Comprehensive data is presented that is well suited for use in validating simulations of wind-body-spray interactions.