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Tutorials
Tutorials show you how to use Simcenter STAR-CCM+ for various applications in a step-by-step format with recommendations for setup, initialization and steps of the solution process specific to the application. Macro and simulation files are available for download for a large proportion of cases.
Multiphase Flow
The tutorials in this set illustrate various Simcenter STAR-CCM+ features for simulating multiphase fluid flow problems
VOF: Tank Sloshing with Adaptive Meshing
To reduce the computational time and resources required for VOF multiphase simulations, Simcenter STAR-CCM+ provides both Adaptive Mesh Refinement (AMR) and Adaptive Time-Stepping. AMR provides adaptation in space and Adaptive Time-Stepping provides adaptation in time. Together, these models improve the resolution of the interface with minimum computational effort by adjusting the mesh and the time-step during the simulation. Additionally, Simcenter STAR-CCM+ offers the Implicit Multi-stepping VOF solver which can be used to decrease computational costs further by sub-stepping the volume fraction transport equation to obtain a sharp interface while allowing for a larger flow time-step.
Setting Up Multi-Stepping
This tutorial case is suitable for applying multi-stepping as time scale of the flow field is larger than the one that is required for the volume fraction transport. Therefore, running this simulation with implicit multi-stepping reduces significantly the runtime over using single-stepping.

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Tutorials
Tutorials show you how to use Simcenter STAR-CCM+ for various applications in a step-by-step format with recommendations for setup, initialization and steps of the solution process specific to the application. Macro and simulation files are available for download for a large proportion of cases.
- Using Tutorial Macros and Files
  Macros, input files, and final simulation files for a range of tutorials are provided as an optional download package on the Support Center website. These macros and final simulation files are provided as an aid to the written tutorials, so that you can check your final results against the downloaded files, or against a simulation that is built and run using the macros.
- Introduction
  Welcome to the Simcenter STAR-CCM+ introductory tutorial. In this tutorial, you explore the important concepts and workflow. Complete this tutorial before attempting any others.
- Foundation Tutorials
  The foundation tutorials showcase the major features of Simcenter STAR-CCM+ in a series of short tutorials.
- Geometry
  The tutorials in this set illustrate various Simcenter STAR-CCM+ features for creating and working with parts and 3D-CAD.
- Mesh
  The tutorials in this set illustrate various STAR-CCM+ features for building CFD meshes.
- Incompressible Flow
  The tutorials in this set illustrate various Simcenter STAR-CCM+ features for incompressible fluid flows as well as porosity and solution recording
- Compressible Flow
  The tutorials in this set illustrate various Simcenter STAR-CCM+ features for compressible fluid flows as well as harmonic balance.
- Heat Transfer and Radiation
  The tutorials in this set illustrate various Simcenter STAR-CCM+ features for heat transfer, radiation, and thermal comfort.
- Multiphase Flow
  The tutorials in this set illustrate various Simcenter STAR-CCM+ features for simulating multiphase fluid flow problems
  - VOF: Gravity-Driven Flow
    This tutorial demonstrates how to set up a gravity-driven flow problem in Simcenter STAR-CCM+. It simulates two-dimensional gravity-driven compressible flow through a channel connecting two chambers.
  - VOF: Capillary Effects
    This tutorial demonstrates how to set up a capillary effects problem in Simcenter STAR-CCM+. It simulates two-dimensional forced flow of liquid glycerine through a nozzle and into an air-filled chamber at atmospheric pressure.
  - VOF: Cavitation
    This tutorial demonstrates how to set up a cavitation problem in Simcenter STAR-CCM+. It simulates a two-dimensional forced flow of water through a nozzle and into an air-filled chamber at atmospheric pressure.
  - VOF: Boiling
    This tutorial demonstrates how to set up a boiling problem in Simcenter STAR-CCM+. It simulates water boiling as it flows over a heated surface.
  - VOF: Melting-Solidification
    This tutorial demonstrates how to set up a melting and solidification analysis in Simcenter STAR-CCM+. It simulates the freezing of water in a pipe.
  - VOF: Tank Sloshing with Adaptive Meshing
    To reduce the computational time and resources required for VOF multiphase simulations, Simcenter STAR-CCM+ provides both Adaptive Mesh Refinement (AMR) and Adaptive Time-Stepping. AMR provides adaptation in space and Adaptive Time-Stepping provides adaptation in time. Together, these models improve the resolution of the interface with minimum computational effort by adjusting the mesh and the time-step during the simulation. Additionally, Simcenter STAR-CCM+ offers the Implicit Multi-stepping VOF solver which can be used to decrease computational costs further by sub-stepping the volume fraction transport equation to obtain a sharp interface while allowing for a larger flow time-step.
    - Prerequisites
      The instructions in the VOF: Tank Sloshing tutorial assume that you are already familiar with certain techniques in Simcenter STAR-CCM+.
    - Loading the Base Simulation
      A base simulation file is provided for this tutorial. The base simulation contains a surface mesh that represents a thin 3D cross-sectional slice of the tank, along with relevant field functions and scenes.
    - Generating the Volume Mesh
      The meshing models and mesh reference values for this simulation are already defined.
    - Selecting the Physics Models
      The Volume of Fluid method tracks the interface between the water and air over time. The VOF Multiphase model uses the High-Resolution Interface Capturing (HRIC) scheme to give an accurate approximation of the volume fraction at cell faces and improve the resolution of the interface. To prescribe the initial position of the water level, a flat wave is defined using the VOF Wave model.
    - Defining the Water and Air Phases
      Create the water and air phases. Both phases use their default material properties.
    - Setting Up the Phase Interaction
      Phase interactions describe the mutual influence of the two materials (phases) air and water on each other. In this simulation, you activate the surface tension force model to enable the computation of surface tension effects between phases in the phase interaction. To enhance stability for larger time-steps, you activate Semi-implicit Surface Tension. Once enabled, the momentum source term due to surface tension is calculated in a semi-implicit way.
    - Defining Tank Acceleration
      The effect of tank motion is modeled using the gravity vector. A table is already provided in the starting simulation that includes the time-dependent profile for the tank acceleration in the X direction.
    - Setting Up Multi-Stepping
      This tutorial case is suitable for applying multi-stepping as time scale of the flow field is larger than the one that is required for the volume fraction transport. Therefore, running this simulation with implicit multi-stepping reduces significantly the runtime over using single-stepping.
    - Setting Up Adaptive Time-Stepping
      The Adaptive Time-Step model automatically determines time-step sizes while the simulation is running. In this simulation, you use the Free Surface Implicit Multi-Step time-step provider which controls the time-step size so that the solver preserves a sharp free-surface interface when using VOF Implicit Multi-Stepping.
    - Setting Up Adaptive Mesh Refinement
      In Simcenter STAR-CCM+, the Adaptive Mesh model provides the general framework for automatic mesh adaption. For VOF multiphase simulations an additional option is provided that supplies the Adaptive Mesh model with adaption criteria based on the position of the free surface.
    - Plotting Results
      You create plots to monitor the CFL Number, the time-step, and the total mass of water of the simulation. To verify the quality of the simulation, you create a plot to monitor the Mass Conservation Error report and monitor the iteration error for the conservation of mass in the water phase.
    - Visualizing Results
      The Volume Fraction scene and CFL Number scene are included in the initial simulation. You specify the appropriate data to display.
    - Setting the Stopping Criteria
      As you are solving an unsteady problem, it is necessary to specify the time-step size and the physical time. The time-step size was specified earlier, when you set up adaptive time-stepping. You run this simulation for 0.7 seconds.
    - Running the Simulation
      Preparation of the simulation is now complete, and you can run the simulation.
    - Analyzing the Results
      View the final scenes and plots, and interpret the results of the simulation.
    - Summary
      This tutorial demonstrated how to set up adaptive mesh refinement and adaptive time-stepping in a gravity-driven two-phase flow simulation in Simcenter STAR-CCM+.
  - Lagrangian: Particle-Laden Flow
    This tutorial demonstrates how to set up a simple Lagrangian multiphase analysis in Simcenter STAR-CCM+. It simulates a particle-laden flow of air through a partially blocked elbow duct.
  - Lagrangian: Solid Particle Erosion
    This tutorial demonstrates how to set up an erosion modeling analysis in Simcenter STAR-CCM+. It simulates the erosion that is caused by solid particles in a liquid flow.
  - Eulerian: Hibiki’s Bubble Column
    This tutorial demonstrates how to model a Eulerian multiphase turbulent flow in Simcenter STAR-CCM+.
  - Eulerian: Mixture Settling
    Settling tanks/separators are widely used in the industry for the purpose of separating a fluid mixture into its gaseous and liquid phases. Separator designs include horizontal and vertical configurations that account for different stages of the process, ranging from absorbing the momentum of incoming fluid to achieving the desired phase separation.
  - Eulerian: Bubble Formation in a Fluidized Bed
    This tutorial demonstrates how to model bubble formation in a fluidized bed in Simcenter STAR-CCM+. It simulates the injection of gas into a fluidized bed and monitors the formation and growth of the bubble.
  - Eulerian: Aeration Tank Degassing
    In industry, aeration tanks facilitate the exchange of gases in various processes within a liquid medium. Degassing is a procedure that actively removes gases from a liquid, such as eliminating excess gases that can build up during the biological treatment of organic pollutants, a process particularly common in waste-water treatment.
  - Eulerian: Wall Boiling
    This tutorial validates the wall boiling model in Simcenter STAR-CCM+ against experimental void and temperature data for high-pressure forced convective boiling.
  - Eulerian: Conjugate Heat Transfer Wall Boiling
    This tutorial demonstrates how to set up a conjugate heat transfer wall boiling analysis in Simcenter STAR-CCM+. It simulates a nuclear fuel pin that is cooled using subcooled boiling under flow conditions typical in the first meter of a 3.7-m long BWR6 reactor channel.
  - Eulerian Multiple Flow Regimes: Pressurized Water Reactor
    This tutorial demonstrates how to use the Multiple Flow Regimes model in Simcenter STAR-CCM+ to simulate the counter-current air-water flow in a pressurized water reactor.
  - Eulerian: Pipe Flow with Multi-Speed AMUSIG
    The Adaptive Multiple Size-Group (AMUSIG) model predicts the size distribution of particles (droplets or bubbles) in a dispersed multiphase flow regime. This tutorial demonstrates how to use the AMUSIG model for predicting the size distribution of hexane droplets in water. The water is flowing up a vertical pipe in which a concentric orifice increases turbulence and so accelerates droplet breakup.
  - Eulerian: Suspension Rheology
    This tutorial demonstrates how to set up a Simcenter STAR-CCM+ simulation that models the flow of a non-Newtonian concentrated suspension.
  - Fluid Film: Liquid Film Flow
    This tutorial demonstrates how to use the fluid film modeling capability of Simcenter STAR-CCM+. It simulates the progress of a rectangular film of water flowing down the wall of a three-dimensional duct.
  - Fluid Film: Binary Liquid Film Flow with Evaporation and Edge Stripping
    This tutorial demonstrates how to use the fluid film modeling capability of Simcenter STAR-CCM+ to set up a multi-component film scenario with evaporation and edge stripping. It simulates the progress of a film mixture of water and ethylene glycol flowing down a partially heated wall.
  - Fluid Film - VOF: Rivulets on an Inclined Plane
    Situations occur where a thin film of liquid forms on a solid surface, for example, rainwater on the windshield of a car. This film can flow and accumulate, and gradually grow into a "thick" film, or a pool of liquid that can no longer be described as a fluid film. These situations are multi-scale problems which, if resolved on all scales (using the VOF multiphase model), would require significant computer resources.
  - Dispersed Multiphase: Airfoil Icing
    When aircraft pass through air containing supercooled liquid water droplets, it is possible for the droplets to impact the aircraft surface and form layers of ice. Ice formation on an aircraft wing changes the aerodynamic properties of the wing, and leads to loss of lift, increase in drag, and a change in pressure distribution. Simcenter STAR-CCM+ provides a technique for simulating the formation of ice on airfoils. This technique relies on the Dispersed Multiphase model to represent the liquid droplets in the air surrounding the airfoil.
  - Hybrid Multiphase: Fountain
    In Simcenter STAR-CCM+ modeling, the term hybrid multiphase refers to modeling multiple flow regimes of a phase material using a combination of several different multiphase models. This modeling capability widens the range of real life multiphase flows that you can simulate.
  - Mixture Multiphase with Large Scale Interfaces: Gear Lubrication
    The Mixture Multiphase (MMP) model is suitable for modeling dispersed multiphase mixtures, where the mixture of phases is represented by weighted physical properties. A single set of conservation equations for mass, momentum, and energy is solved for the mixture together with transport equations for phase volume fractions.
  - Viscous Multiphase: Two-Layer Pipe Co-Extrusion
  - Smoothed-Particle Hydrodynamics (SPH): Gearbox Lubrication
    Gear mechanisms require adequate lubrication for long-term optimum performance and efficiency. Simcenter STAR-CCM+ provides the Smoothed-Particle Hydrodynamics (SPH) model with which you can simulate the flow of lubricant around the parts of a gear mechanism and determine whether adjustments are necessary.
- Discrete Element Method
  The tutorials in this set illustrate various Simcenter STAR-CCM+ features for simulating Discrete Element Method problems
- Motion
  The tutorials in this set illustrate various STAR-CCM+ features for simulating problems with moving geometries and meshes, dynamic fluid body interaction, and rigid body motion:
- Reacting Flow
  The tutorials in this set illustrate various Simcenter STAR-CCM+ features for simulating reacting flows such as combustion.
- Solid Stress
  The tutorials in this set illustrate various Simcenter STAR-CCM+ features for computing deformation, strain, and stresses in solid regions. They also show how such computations can be coupled to the fluid behavior in an analysis of fluid-structure interaction.
- Aeroacoustics
  The tutorials in this set illustrate various Simcenter STAR-CCM+ features for solving aeroacoustic simulations.
- Electromagnetism
  The following tutorials illustrate features for solving problems that involve electromagnetic fields.
- Electrochemistry
  The following tutorial demonstrates chemical reactions induced by an electrical current.
- Battery
  The tutorials in this set illustrate various Simcenter STAR-CCM+ features for setting up a battery model:
- Automation
  The tutorials in this set illustrate various Simcenter STAR-CCM+ automation and macro features.
- Design Exploration
  The tutorials in this set illustrate various features for running design exploration studies in Design Manager.
- Coupling with CAE Codes
  The tutorials in this set illustrate various Simcenter STAR-CCM+ features for coupling with CAE codes:
- Analysis Methods
  The tutorials in this set illustrate various Simcenter STAR-CCM+ features for analysing and visualizing simulation data.
- Simcenter STAR-CCM+ In-cylinder
  The tutorials in this set illustrate features for simulating internal combustion engines in Simcenter STAR-CCM+ using the dedicated add-on Simcenter STAR-CCM+ In-cylinder.

Setting Up Multi-Stepping

This tutorial case is suitable for applying multi-stepping as time scale of the flow field is larger than the one that is required for the volume fraction transport. Therefore, running this simulation with implicit multi-stepping reduces significantly the runtime over using single-stepping.

For more information, see Multi-Stepping Guidelines.

An important quality of a system of immiscible phases, in this case air and water, is that the fluids always remain separated by a sharp interface. For this simulation, a small time-step is required to obtain a sharp interface. With single-stepping, you must use a time-step that is small enough to ensure that the CFL number remains low (typically 0.5) throughout the simulation, resulting in a long simulation run time. When implicit multi-stepping is used, the Segregated VOF solver performs multiple steps per time-step and the Courant number condition from Eqn. (2593) for flow time-step $Δ t$ is modified to the following:

Figure 1. EQUATION_DISPLAY

{C o}_{(τ)} = \frac{{C o}_{(Δ t)}}{N_{i m p}} \leq 0.5

(5252)

where $τ = \frac{Δ t}{N_{i m p}}$ is the effective convective time-step for the $N_{i m p}$ fixed number of user-defined sub-steps used for solving the volume fraction transport equation.

If the flow features are resolved sufficiently well at a time-step size that is, for example 4 times greater than the global time-step $Δ t$ , increase the global time-step by 4 and specify the same amount of implicit sub-steps $N_{i m p} = 4$ . For example, for a sub-stepping CFL of ${C o}_{(τ)} = 0.5$ the resulting CFL will be ${C o}_{(Δ t)} = 2$ .

To set up multi-stepping:

Select the Solvers > Segregated VOF node and set Solution Strategy to Implicit Multi-Step.
Select the Solvers > Segregated VOF > Implicit Multi-Step node and set the following properties:

Property Setting

Number of Steps 4
Save the simulation.