Particle—Introduction
Particle transport modeling is a category of multiphase models that follows the Euler-Lagrange approach. This model treats the dispersed fluid such as particles, bubbles, or droplets as individual particles or as a discrete phase through the continuous flow phase in a Lagrangian way. This model is also known as Discrete Phase (Particle) Model (DPM). In this approach, the fluid phase is treated as a continuum and is governed by the continuity and Navier-Stokes equations. For the discrete phase, it consists of a definite number of particles that move along or through the continuous fluid flow. You assume that the volume of a particle does not displace a fluid phase. A set of ordinary differential equations (ODE) in time, including equations for position, velocity, temperature and masses of species, are solved to track the trajectory of each individual particle as it traverses the flow domain. The particle-fluid interactions (the exchange of momentum, mass, and energy) can be one-way or two-way coupling: the flow would always affect the particle motions, but the discrete phase may or may not have significant counteracting influences on the continuous fluid phase depending on the characteristics of the discrete phase. To track each individual particle movement in time and space, the number of discrete phase equations solved is proportional to the number of particles. Particle-particle interactions such as collision, break-up, and coalescence complicate the tracking procedure and increase computational cost. For practical use, the discrete multiphase model assumes that the second phase is sufficiently dilute so that particle-particle interactions and the effects of the particle volume fraction on the flow phase are negligible. When you select the Euler-Lagrange approach, the discrete phase must be at a low volume fraction, less than 10%. If the dispersed phase has a higher volume fraction, it is recommended that you consider such a dispersed phase as a continuous phase and adopt the Euler-Euler multiphase models in the Multiphase module.
Particle is a module in Creo Flow Analysis. To access this module, follow the steps listed below:
1. Right-click Physics and click Select Physics Models. The Physical Model Selection dialog box opens.
2. Select the module from Available Modules. In the Flow Analysis Tree, under Physics, Radiation is added.
The module is explained as follows:
Physics—Definitions, terminology, constants, models and methods used in particle modeling.
Particle Parameters—Parameters and methods used in particle modeling.
Boundary Conditions—Specifying conditions for the entities such as boundaries, interfaces, volumes, and the outputs from the module.
Output Variables—Expressions created for specifying conditions and postprocessing associated with particle.