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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.
Discrete Element Method
The tutorials in this set illustrate various Simcenter STAR-CCM+ features for simulating Discrete Element Method problems
Flexible Fiber Model: Lawnmower

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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
- Discrete Element Method
  The tutorials in this set illustrate various Simcenter STAR-CCM+ features for simulating Discrete Element Method problems
  - DEM Particles in a Conveyor
    The purpose of this tutorial is to provide a guide to setting up a simulation using the Discrete Element Method.
  - DEM Particle Settling
    This tutorial simulates a three-dimensional solid flow through a model blast furnace to predict the formation of the deadman region at the base of the furnace.
  - Cylindrical Particles in a Rotating Drum
    This tutorial simulates a large number of cylindrical-shaped tablets tumbling in a rotating drum and being sprayed with a protective coating.
  - Arbitrarily Shaped Particles: DEM Polyhedra
    This tutorial demonstrates how to compose and inject DEM particles of an arbitrary shape.
  - Meshfree DEM: Excavator
    For DEM simulations of particles that are not significantly impacted by the surrounding fluid, Simcenter STAR-CCM+ allows you to model the particle behavior without requiring a volume mesh. This type of simulation is known as meshfree DEM.
  - Coarse Grain Particles: Fluidized Bed
  - Flexible Fiber Model: Lawnmower
    - Loading the Starting Simulation File
      For this tutorial, you are provided with a starting simulation file that contains the geometry of the lawnmower blade inside the computational domain and pre-defined regions with boundaries. Since you are using the meshless DEM methodology for this tutorial, there is one solid region for the lawnmower blade and a particle region for the encompassing computational domain. The parameters that you use to specify several settings in the tutorial are already included on the starting simulation file.
    - Selecting the Physics Models and Defining the Gravitational Field
      You use the meshfree Discrete Element model, which is part of the Lagrangian Multiphase framework, to model the grass blades as DEM flexible fiber particles within the domain. The gravity vector acts in the negative y direction.
    - Defining the Grass Blades
    - Defining the Cutting Blade Rotation
      You define only a rotational motion for the lawnmower blade, which rotates around the y axis with 3625 rpm. The translational motion of the lawnmower is accounted for by specifying a relative tangential velocity at the bottom boundary, that is, the grass moves towards the lawnmower blade.
    - Defining the Grass Blade Interactions
      You define the behaviour of the grass blades when they interact with each other, when they hit the domain walls or when they fall to the ground.
    - Placing the Grass Blades
      A table injector injects the grass blades at locations given by an XYZ table.
    - Visualizing the Moving Grass
      You create a visualization scene that displays the grass blades colored with their segment length. The visualization scene also has annotations to display the total grass blades injected and cut in the simulation. To create an animation of the lawnmower blade cutting the grass blades, you set up a solution history file. You set up a histogram plot to investigate the variation in grass blade segment length as the lawnmower cuts the grass blades. The visualization scene and reports for the total number of grass blades injected and cut have been created on the starting file for your convenience, but you are required to complete the setup. You create and set up the solution history file and histogram plot.
    - Running the Simulation
      You run the transient simulation for a physical time of 0.3 s with a time step of 0.0001 s.
    - Analyzing the Results
      Create an animation of the simulation so that the results can be further analyzed. You also view the histogram of particle component bonded size plot.
- 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.

Flexible Fiber Model: Lawnmower

Fibers are used in several applications, for example, to create fiber-reinforced plastics and cements in the chemical industry, as an addition to molten plastic during injection molding, during cotton manufacturing, in biomass reactors, or representing crops in the agricultural industry.

Simcenter STAR-CCM+, provides the Flexible Fiber model that allows you to model fibers as Discrete Element Method (DEM) particles that are formed by connecting several identical cylinders bonded end to end. The bonds can perform axial extension, compression, and bending deformations – and they can be broken. The Flexible Fiber model does not require a high number of segments to compose the fiber, which makes it computationally efficient.

This tutorial demonstrates the workflow for modeling grass cutting using meshfree DEM in combination with the Flexible Fiber model and the Impact Cutting model. Meshfree DEM is an efficient method that computes only the DEM particle behaviour, not the surrounding fluid, and therefore does not require a mesh. The objective of the simulation is to assess the quality of the grass cutting process. You analyze the length distribution of the grass blades during cutting in the form of a histogram plot.

In this tutorial, you simulate a simplified rotating lawnmower blade that cuts grass. The following image shows a snapshot of the simulation:

The lawnmower blade performs a rigid body rotation around the y axis with a rotational speed of 3625 rpm. The grass blades are modeled as flexible fiber DEM particles, each of which is composed of 10 cylindrical segments. Initially, each grass blade has a height of 114.3 mm and a diameter of 5.08 mm. In reality, the lawnmower blade also performs a translational motion. In this tutorial, however, the translational motion is accounted for by specifying a relative velocity of the grass blades instead. The grass blades move towards the lawnmower blade at a velocity of 2 m/s. The Impact Cutting model makes a single cut on a grass blade when the lawnmower blade impacts the grass blades with a velocity higher than 20 m/s. The effect of air flow due to lawnmower blade rotation on the grass blades is considered through user-defined body forces, specifically, a drag force acting on the grass blades.