Nukiyama-Tanasawa equation

INFRARED TECHNOLOGY AND RAMAN SPECTROSCOPY - INFRARED TECHNOLOGY] (Vol 14) Nukiyama-Tanasawa equations... 

Determine the mean droplet diameter d . Use the Nukiyama-Tanasawa equation ... 

Similarly, a range of equations or formulas are available for prediction of droplet size for sprays from two-fluid nozzles. The most widely cited in the literature is the Nukiyama-Tanasawa equation, which, however, is complicated and of doubtful validity at high flow rates. A much simpler equation has been proposed by Geng Wang et al. ... 

Fig. 24.15 The original and modified versions of the Nukiyama-Tanasawa equation using properties of water with QaIQl = 400, U2 = 10, when (a) plotted against Ur and (b) against Qa/Qi...

Browner, R. F., Experimental Evaluation of the Nukiyama-Tanasawa Equation for Pneumatic Nebulisers Used in Plasma Atomic Emission Electroscopy, J. Anal. Atom. Spectrosc., Vol. 6, February 1990, pp. 61-66. 

Three widely used distribution equations, discussed by Bevans (JL), include the Rosin-Rammler (7L) and Nukiyama-Tanasawa (6L) equations as well as the log-probability equation. A fourth relationship, the upper-limit equation of Mugele and Evans (5L), is also discussed. Hawthorne and Stange also discuss the Rosin-Rammler relationship (4L, 8L). An excellent analysis of distributions is given by Dubrow (SL), who has studied atomized magnesium powders. 

Droplet Size Distribution, Most sprays comprise a wide range of droplet sizes. Some knowledge of the size distribution is usually required, particularly when evaluating the overall atomizer performance. The size distribution may be expressed in various ways. Several empirical functions, including the Rosin-Rammler (25) and Nukiyama-Tanasawa (26) equations, have been commonly used. 

A number of theoretical studies of venturi performance have been made to produce theoretical models that can predict performance from first principles. One of the key areas of uncertainty has been the droplet size formed by the venturi. Typically, this is estimated using the Nukiyama and Tanasawa equation to estimate the surface-mean droplet diameter ... 

Most of the investigators have assumed the effective drop size of the spray to be the Sauter (surface-mean) diameter and have used the empirical equation of Nukiyama and Tanasawa [Trans. Soc. Mech. Eng., Japan, 5, 63 (1939)] to estimate the Sauter diameter ... 

B) have found excellent correlation between the measured sizes of drops atomized by high-velocity gas streams with the equations developed by Nukiyama and Tanasawa (6L), so long as conditions are held within certain limits. The behavior of sprays of 7i-heptane, benzene, toluene, and other fuels has been studied by Garner and Henny (SB) by use of a small air-blast atomizer under reduced pressures. A marked increase in the Sauter mean diameter was obtained for benzene and toluene as compared with n-heptane, which parallels their poor performance in gas turbines. Duffie and Marshall (2B) give a theoretical analysis of the breakup characteristics of a viscous-jet atomizer and show high-speed photographs of the process. 

AP is the pressure drop, cm of water pt and pg are the density of the scrubbing liquid and gas respectively, g/cm3 Ug is the velocity of the gas at the throat inlet, cm/s Q,IQg is the volumetric ratio of liquid to gas at the throat inlet, dimensionless lt is the length of the throat, cm Cm is the drag coefficient, dimensionless, for the mean liquid diameter, evaluated at the throat inlet and di is the Sauter mean diameter, cm, for the atomized liquid. The atomized-liquid mean diameter must be evaluated by the Nukiyama and Tanasawa [Trans. Soc. Mech Eng. (Japan), 4, 5, 6 (1937-1940)] equation ... 

Aspiration rate is only a small part of the overall transport process in flame spectrometry. The production of aerosol and its transport through the spray chamber are also of great importance. The size distribution of aerosol produced depends upon the surface tension, density, and viscosity of the sample solution. An empirical equation relating aerosol size distribution to these parameters and to nebulizer gas and solution flow rates was first worked out by Nukiyama and Tanasawa,5 who were interested in the size distributions in fuel sprays for rocket motors. Their equation has been extensively exploited in analytical flame spectrometry.2,6-7 Careful matrix matching is therefore essential not only for matching aspiration rates of samples and standards, but also for matching the size distributions of their respective aerosols. Samples and standards with identical size distributions will be transported to the flame with identical efficiencies, a key requirement in analytical flame spectrometry. 

Equation 24.1. iii by Nukiyama and Tanasawa [15] is one of the most commonly used correlations for plain jet nozzles. However, it neglects the effect of the diameter of the discharge orifice. In their experiment though, Nukiyama and Tanasawa did investigate the effects of the exit orifice diameter, but concluded... 

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