Laboratory study of the generation of spray over water

Abstract

A hot‐film anemometer was used in a wind flume to measure the size and number of water droplets over the air‐water interface. Experiments were conducted both with and without mechanically generated waves and each with both freshwater and saltwater. The effects of wind speed and wave height on the vertical distribution of spray were investigated. The mechanism of spray generation was explored. The results of this study indicate that the vertical distribution of the total horizontal flux of droplets can be expressed by a logarithmic distribution. The drop size distribution (drop size spectrum) at a fixed elevation can be described by a negative power law of drop diameter. The droplet production mechanism by bursting bubbles suggested by Blanchard (1963) is found to account for only a portion of the total production. The effect of spray on the remote sensing of the air‐sea interface is evaluated. The spray is found to affect strongly the measurements obtained from a radiometer.

Spray in the atmospheric surface layer: Review and analysis of laboratory and oceanic results

“…Various techniques have been used to measure spray. The size of droplets has been determined from craters on a filter paper [Toba, 1961], direct photographs [Monahah, 1968], marks on an oil-coated plate [Preobrazhenskii, 1973], and voltages induced on a hot film probe [Lai and Shemdin, 1974] and on a capacitance wire [Wang and Street, 1978a, b]. Finally, an optical technique was used by Wu [ 1973] to measure simultaneously the size and the velocity of the droplet.…”

“…In addition, the knowledge of droplet distribution near the sea surface is helpful in solving practical problems such as combating ship icing, conducting oceanographic measurements [Schmitt et al, 1978], and designing offshore structures. Systematic measurements of spray were conducted by Toba [1961], Monaban [1968], Wu [1973], Lai and Shemdin [1974], and Wang and Street [1978a, b]. Earlier studies tended to emphasize the initiation of spray, and later results consisted of vertical distributions of droplet numbers and sizes at various elevations under different wind velocities; some data on droplet speeds were also provided by Wu.…”

Offshore drilling rig ice accretion modeling including a surficial brine film

“…When the wind speed is below 15 m/s wind-generated spray mass flux is neglected; above 15 m/s a formula given in Horjen, 1990Horjen, , 2013, which is based on various measurements from the wave crest up to 7 m above the msl (Wu et al (1984), Monaham (1968), Lai and Shemdin (1974) and Preobrazhenski (1973)) is used. Fig.…”

Laboratory modelling of the transfer processes between the ocean and atmosphere in the boundary layers

“…As it was mentioned before sprays play a key role in the transfer processes. Presence of sprays in the air could be controlled by the detecting spikes in the signals of hot film close to the way used in [36]. Thus the closed symbols on the plot show the data obtained in no-spray conditions, and the open symbols denote the data obtained in the presence of spray.…”