Cubic Formula for Determination of the Drop Size During Atomization of Liquid Jets in Co- and Cross-Flow of Air

Author(s):  
T.-W. Lee ◽  
Jung Eun Park ◽  
Ryoichi Kurose

Using the integral formulation of the conservation equations as in our previous work, we can determine the drop size and its distributions in liquid sprays in co- and cross flow of air. The energy balance dictates that the initial kinetic energy of the gas and injected liquid be distributed into the final surface tension energy, kinetic energy of the gas and droplets, and viscous dissipation incurred. The mass and energy balance for the spray flows render to an expression that relates the drop size to all of the relevant parameters, including the gas- and liquid-phase properties and velocities. The results agree well with experimental data and correlations for the drop size. The solution also provides for drop size-velocity cross-correlation, leading to drop size distributions based on the gas-phase velocity distributions. These aspects can be used in estimating the drop size for practical applications, in synthesizing the data as a function of relevant variables, and also in integration into CFD for atomization algorithm.

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
T.-W. Lee ◽  
J. E. Park

We have used the integral form of the conservation equations, to find a cubic formula for the drop size during in liquid sprays in coflow of air (air-blast atomization). Similar to our previous work, the energy balance dictates that the initial kinetic energy of the gas and injected liquid will be distributed into the final surface tension energy, kinetic energy of the gas and droplets, and viscous dissipation. Using this approach, the drop size can be determined based on the basic injection and fluid parameters for “air-blast” atomization, where the injected liquid is atomized by high-speed coflow of air. The viscous dissipation term is estimated using appropriate velocity and length scales of liquid–air coflow breakup. The mass and energy balances for the spray flows render to an expression that relates the drop size to all of the relevant parameters, including the gas- and liquid-phase velocities and fluid properties. The results agree well with experimental data and correlations for the drop size. The solution also provides for drop size–velocity cross-correlation, leading to computed drop size distributions based on the gas-phase velocity distribution. This approach can be used in the estimation of the drop size for practical sprays and also as a primary atomization module in computational simulations of air-blast atomization over a wide range of injection and fluid conditions, the only caveat being that a parameter to account for the viscous dissipation needs to be calibrated with a minimal set of observational data.


2004 ◽  
Vol 30 (5) ◽  
pp. 499-520 ◽  
Author(s):  
D.C.Y. Wong ◽  
M.J.H. Simmons ◽  
S.P. Decent ◽  
E.I. Parau ◽  
A.C. King

1977 ◽  
Vol 44 (3) ◽  
pp. 385-388 ◽  
Author(s):  
P. Lafrance ◽  
R. C. Ritter

Experiments were performed to measure the size of drops resulting from the capillary breakup of laminar liquid jets. Random noise was used to perturb the jet and an electro-optical instrument was used to measure drop sizes. Drop size distributions show two peaks as predicted by nonlinear theory. The large group has a mean size as predicted by the most unstable perturbation mode, in agreement with the commonly accepted but previously untested assumption.


Author(s):  
Sachin Khosla ◽  
D. Scott Crocker

A numerical model for liquid jet atomization in a subsonic gas cross flow has been developed and incorporated into a CFD code. The model is designed primarily for the shear breakup regime, which is appropriate for many fuel injection applications. The model considers Weber number and momentum flux ratio ranges that are dominated by either jet surface breakup or column breakup. A boundary layer stripping model has been modified to account for both shearing from the column and shear primary breakup of large drops. Further secondary breakup was modeled with the Rayleigh-Taylor model. The effect of drop distortion on the drag is also considered. Results of the model have been compared with experimental data for jet-A liquid jets in air cross flows with varying pressure, air velocity, and liquid-to-gas momentum flux ratio. Comparisons were made for drop volume flux and drop size as a function of distance from the injector wall. Trends were captured for liquid penetration associated with varying momentum flux ratio, and for drop size as a function distance from the wall. In general, agreement between measurements and CFD predictions were quite good. Areas of disagreement could be reasonably explained by the model’s inherent inability to capture the wake flow behind the liquid column.


2018 ◽  
Vol 28 (3) ◽  
pp. 241-254 ◽  
Author(s):  
T.-W. Lee ◽  
Jung Eun Park ◽  
Ryoichi Kurose
Keyword(s):  

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