Phase Doppler interferometry measurements in water sprays produced by residential fire sprinklers

A phase Doppler interferometry (PDI) system was used to characterize the water sprays produced by four residential fire sprinklers. Four pendent sprinklers with K-factors ranging from 7.2 x 10(-5) m(3) s(-1) kPa(-0.5) (3.0 gal min(-1) psig(-0.5)) to 1.35 x 10(-4) m(3) s(-1) kPa(-0.5) (5.6 gal min(-1) psig(-0.5)) were investigated. The measurements include characteristic size (arithmetic mean diameter, volume mean diameter, Sauter mean diameter), mean velocity (axial and radial components), and liquid volume flux. The effect of water pressure on drop size was also investigated. The mean drop size (flux-averaged volume diameter, (D(30)) over bar) was found to be proportional to p(-1/3) over the range 93 kPa less than or equal to P less than or equal to 200 kPa. Published by Elsevier Science Ltd.