Droplet deformations

TLCP droplet deformation in processing equipment and fibrillation, and recent advances in the fibrillation techniques. 

The mechanism of droplet deformation can be briefly summarized as follows. The factors affecting the droplet deformation are the viscosity ratio, shear stress, interfacial tension, and droplet particle size. Although elasticity takes an important role for general thermoplastics droplet deformation behavior, it is not known yet how it affects the deformation of TLCP droplet and its relationship with the processing condition. Some of... 

Concerning a liquid droplet deformation and drop breakup in a two-phase model flow, in particular the Newtonian drop development in Newtonian median, results of most investigations [16,21,22] may be generalized in a plot of the Weber number W,. against the vi.scos-ity ratio 8 (Fig. 9). For a simple shear flow (rotational shear flow), a U-shaped curve with a minimum corresponding to 6 = 1 is found, and for an uniaxial exten-tional flow (irrotational shear flow), a slightly decreased curve below the U-shaped curve appears. In the following text, the U-shaped curve will be called the Taylor-limit [16]. 

The droplet deformation is also time-dependent. A practicable dimensionless breakup time can be defined as ... 

On the basis of experimental observations (Fig. 3.27), Senda et al.[335h415] proposed six modes for water droplet deformation, and breakup during impingement on a hot surface coupled with heat transfer and evaporation (Fig. 3.28). Each mode occurs under a specific combination of surface temperatures and impact conditions, as described below. 

Atomization, or generally speaking droplet generation, is an extremely complex process that cannot yet be precisely predicted theoretically. The lack of general theoretical treatment of droplet processes has led to the development of numerous empirical correlations for droplet properties as a function of process parameters and material properties. In this chapter, empirical and analytical correlations for the prediction of droplet properties, such as droplet size distribution and droplet deformation characteristics will be summarized from experimental observations and theoretical analyses in available literature. 

For the deformation of droplets of normal liquids at low impact velocities on a horizontal plane surface without phase change, Tan et al)513 developed a physical-mathematical model with a droplet falling from a certain height under the influence of gravity. They derived quantitative relations for the dimensions of the deformed droplet, including the effects of initial droplet diameter, height of fall, and thermophysical properties of liquid. In this model, the behavior of droplet deformation was assumed to be governed by... 

The correlations derived from the analytical models, numerical modeling, and experimental results are listed in Table 4.21. The dimensionless numbers used to describe the droplet deformation... 

Table 4.22a. Dimensionless Numbers Used to Describe Droplet Deformation Processes with Simultaneous Heat Transfer and Phase Change (Solidification or Evaporation)...

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