Lagrangian Multi-Phase Flows

Many scientific and engineering problems can benefit from the simulation of two-phase flows. Examples include the design of power generating devices (such as internal combustion engines and liquid or solid rocket engines), pollution control equipment, nozzle designs, filter designs, and more.  In each application, the two-way coupling of the transportation of momentum, heat, and mass between the continuous phase and particulate phase plays an important role in the behavior of these flows.

STORM's advanced capabilities and features permit rigorous modeling of both flow and particulate behavior in complex, interacting fluid-particle phenomena.

 Types of Problems

       Liquid particles in a gas continuous phase

       Solid particles in a gas continuous phase

       Liquid particles in a liquid continuous phase

       Solid particles in a liquid continuous phase

       Gas bubble in a liquid continuous phase

 Lagrangian Methodology

Simulating two-phase flows that involve particle tracking requires the Lagrangian methodology because of its accuracy in calculating fluid-particle interaction between a dispersed phase and a continuous fluid. To track the particles in a realistic manner, the Lagrangian methodology directly models the physics of particle behavior in conjunction with the flow field.  It treats the particles as discrete entities in the flow field and calculates their relative trajectories. It then simultaneously describes, and consequently solves, the continuous phase using an Eulerian approach.  The flow field may be laminar or turbulent.

The Lagrangian methodology couples the solution of the dispersed phase to the continuous phase by representing the dispersed phase as a finite number of computational particles.  Then, the mass, momentum, and heat exchanges are computed between the two phases.  The Eulerian phase takes the exchanged amounts and adds them to the source term of the governing equations to quantify the effects of the dispersed phase. The particulate phase takes the exchanged amounts and calculates the particle characteristics (velocities and positions). Interactions between particles and particles with walls are modeled as well.

Particle Injection Methodology

STORM's Lagrangian method makes it easy for the investigator to describe how the particulate phase is injected into the computational domain.  STORM provides detailed injection parameters that describe various planar or conical particle injection patterns. Conical injection patterns may be solid-cone or hollow-cone geometries, and can be applied at any arbitrary angle. Another injection parameter addresses non-uniform particle size distributions, which are often encountered in real-world particulate flow problems.

Switch-on Physical Models

STORM also includes sophisticated “switch-on” physical models that permit more accurate description of the complex interactions between the particulate phase and continuous phases. These models further describe specific, observable particle behaviors, such as evaporation, breakup, combustion, and turbulent dispersion.  CFD2000 also accounts for complex particle collision behavior based on particle-to-particle collision and/or particle-to-boundary collision, including the effects of sticking and bouncing to boundary surfaces.