Reitz-Diwakar Droplet Breakup Model Reference

The Reitz-Diwakar Breakup model is based on observed length- and time-scales of droplet breakup.

The Reitz-Diwakar breakup model, [689] and [690], assumes that breakup occurs in one of two possible modes:

  • Bag breakup, in which the non-uniform pressure field around the droplet causes it to expand in the low-pressure wake region and eventually disintegrate when surface tension forces are overcome.
  • Stripping breakup, in which liquid is sheared or stripped from the droplet surface.

The model calculates local disturbances on a cylindrical free surface and traces the growth rate of the most unstable mode. It does not generate child parcels, hence it is computationally efficient to run. It can be used to estimate the importance of breakup before turning to a more complex model, or to provide support to conclusions obtained from such a model.

Theory See Reitz-Diwakar Breakup Model.
Provided By Lagrangian Multiphase > Lagrangian Phases > [phase] > Models > Secondary Breakup
Example Node Path Lagrangian Multiphase > Lagrangian Phases > [phase] > Models > Reitz-Diwakar Breakup
Requires
  • Material: one of Gas, Liquid, Multiphase, Multi-Component Gas, Multi-Component Liquid
  • (For Multiphase, Multi-Component Gas or Multi-Component Liquid, further models are required to expose the Flow models.)
  • Flow: Coupled or Segregated
Under the Lagrangian Multiphase model:
  • Particle Type: Material Particles
  • Material: Liquid or Multicomponent Liquid
  • Particle Shape: Spherical Particles
Properties Key properties are: WeCrit. See Reitz-Diwaker Breakup Properties.
Activates Materials See Reitz-Diwaker Breakup Material Properties.
Field Functions Droplet Surface Tension, Droplet Weber Number. See Reitz-Diwaker Breakup Field Functions.

Reitz-Diwaker Breakup Properties

WeCrit
Minimum Weber number for breakup, see Eqn. (3106).
Cb2
Bag breakup time-scale coefficient, see Eqn. (3109).
Cs1
Coefficient prescribing the onset of stripping breakup, see Eqn. (3108).
Cs2
Stripping breakup time-scale coefficient, see Eqn. (3109).

Reitz-Diwaker Breakup Material Properties

Surface Tension
The droplet surface tension σ.
Method Corresponding Method Node
Mixture
Mixture
Available when the Multicomponent Liquid model is selected. Specifies the mixing law for the liquid in the droplet.
The exponent r in Eqn. (143). The default is 1.

Reitz-Diwaker Breakup Field Functions

Droplet Surface Tension
The surface tension of the droplet σ .
Droplet Weber Number
The droplet Weber number We in Eqn. (3093).