Lagrangian MultiPhase Flows 

Many scientific and engineering problems can benefit from the simulation of twophase 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 twoway 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 fluidparticle 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 twophase flows that involve particle tracking requires the Lagrangian methodology because of its accuracy in calculating fluidparticle 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 solidcone or hollowcone geometries, and can be applied at any arbitrary angle. Another injection parameter addresses nonuniform particle size distributions, which are often encountered in realworld particulate flow problems. 

Switchon Physical Models  
STORM also includes sophisticated “switchon” 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 particletoparticle collision and/or particletoboundary collision, including the effects of sticking and bouncing to boundary surfaces. 