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Phase Doppler Interferometry Measurements in Water Sprays Produced by Residential Fire Sprinklers.


pdf icon Phase Doppler Interferometry Measurements in Water Sprays Produced by Residential Fire Sprinklers. (489 K)
Widmann, J. F.

Fire Safety Journal, Vol. 36, No. 6, 545-567, September 2001.

Keywords:

water sprays; sprinklers; drop sizes; fire suppression; size distribution; velocity measurement; interferometry

Abstract:

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 10-5m3s-1kPa-0.5 (3.0 gal min-1 psig-0.5) to 1.35 x 10-4m3s-1kPa-0.5 (5.6 gal min-1 psig-0.5) were investigated. The measurements include (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, D30) was found to be proportional to P-1/3 over the range 93 kPa