1971 Volume 4 Issue 3 Pages 257-263
The standard deviation of sprayed drop size distribution was investigated by applying a simple stochastic model to the disintegration process of a liquid sheet. The disintegration of the liquid sheet was considered to start from the detached sheet which is cut off by the most unstable wave and which has a width equivalent to half the wavelength. Then the disintegration process was assumed to be like a random walk model in which the probability of disintegration is unchanging regardless of the size of liquid pieces and in which all pieces have the same chance of disintegration.
The logarithmic standard deviation and the relative mean size were obtained as a function of Reynolds number by using experimental data on a fan nozzle. The original size of breaking liquid sheet was determined from the thickness measured by the optical interference method and from the width by stroboscopic photographs. As a result, higher Reynolds numbers gave smaller mean size of liquid drop and lower standard deviation.