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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.
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.
Uniflow Two-Stroke Engine
Two-stroke engines complete the power cycle with two strokes of the piston while turning the crankshaft once (360 degrees). With Simcenter STAR-CCM+ In-cylinder, you can simulate different types of two-stroke engines—uniflow, loop flow, or cross flow engines.
Importing the Geometry
You start the simulation setup from a CAD geometry of the two-stroke engine in Parasolid format.

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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
- 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.
  - Gasoline Engine: Motored
    Simcenter STAR-CCM+ In-cylinder provides an automated method to perform transient moving-mesh analyses of internal combustion engines.
  - Gasoline Engine: Charge Motion
    Simcenter STAR-CCM+ In-cylinder provides methods for predicting the charge motion in an internal combustion engine, including the injection of liquid fuel, the subsequent evaporation and mixing process, and the formation of fuel film on the engine walls.
  - Gasoline Engine: ECFM-3Z Combustion
    In Simcenter STAR-CCM+ In-cylinder, you can simulate the combustion process in a gasoline engine using the Extended Coherent Flame Model Three Zone (ECFM-3Z).
  - Diesel Engine: Closed-Cycle Sector Model
    A closed-cycle analysis investigates the injection, ignition, and combustion process in an engine cylinder with all intake and exhaust valves closed. For axisymmetric cylinder geometries, Simcenter STAR-CCM+ In-cylinder allows you to model these stages of the engine cycle in a sector of the actual cylinder geometry in order to reduce runtime.
  - Uniflow Two-Stroke Engine
    Two-stroke engines complete the power cycle with two strokes of the piston while turning the crankshaft once (360 degrees). With Simcenter STAR-CCM+ In-cylinder, you can simulate different types of two-stroke engines—uniflow, loop flow, or cross flow engines.
    - Prerequisites
      This tutorial guides you through the setup of the two-stroke engine simulation using the dedicated Simcenter STAR-CCM+ In-cylinder add-on in Simcenter STAR-CCM+.
    - Importing the Geometry
      You start the simulation setup from a CAD geometry of the two-stroke engine in Parasolid format.
    - Setting Up the Engine Models
      Here, you select the physics models for ignition and combustion.
    - Setting Up the Fuel
      For this tutorial, you use methane ( $C H_{4}$ ) as fuel.
    - Creating the Two-Stroke Engine Parts
      Based on the imported CAD geometry, you create Engine Parts for the cylinder, the exhaust valve, the intake port, and the GAVs.
    - Setting the Initial Conditions
      You initialize the cylinder and the GAVs with methane gas at a pressure of 12 bar and a temperature of 1000 K. In the exhaust port, the methane gas has an initial pressure and temperature of 1.5 bar and 700 K, respectively. Finally, you initialize the intake port with air at a pressure of 2.5 bar and a temperature of 330 K.
    - Setting Up the Piston Motion
      Here, you specify the engine stroke and the length of the connecting rod, which both directly affect the piston motion.
    - Setting the Inlet and Outlet Boundary Conditions
      Air enters through the intake port inlet with a static temperature of 330 K and a pressure of 2.5 bar. At the inlets of the GAVs, you introduce methane gas with a total temperature of 330 K, where the gas admission starts at 230.0 deg CA and ends at 246.0 deg CA. You import a table that describes the mass flow rate of the methane gas as a function of crank angle. To avoid diffusion of flow quantities at the GAV inlets, you exclude the flow-boundary diffusion fluxes. At the exhaust port outlet, you set a pressure of 1.5 bar and a static temperature of 700 K.
    - Setting Up the Exhaust Valve Motion
      For the motion of the valve, you import a table that describes the valve lift as a function of crank angle.
    - Setting Up the Ignitor
      For the ignition of the air-fuel mixture, you create an ignitor Engine Part, which provides a template for defining the ignition location and timing. You set the ignition timing to 350.0 deg CA, which corresponds to 10.0 deg CA BTDC.
    - Setting Operating Conditions
      The two-stroke engine in this tutorial operates at a constant angular velocity of 1000 rpm. The simulation starts at 90 deg CA and ends at 450 deg CA.
    - Setting Up Automatic Time-Step Control
      To aid solution convergence, you enable automatic time-step control. For two stroke engines, this approach adjusts the time-step based on specified offsets between the moving piston and the plenums. Here, you increase the offset shortly after intersection between liner and plenums during which the automatic time-step control applies a small time-step.
    - Defining Mesh Refinement Zones
      You define mesh refinement zones on the GAVs and intake port sides of the sliding interfaces using geometries that are based on simple shape templates.
    - Setting Up the Mesh
      To reduce runtime, you increase the base size of the mesh. To aid solution convergence, you refine the mesh for the intake port and the GAVs next to the interfaces
    - Preparing the Plots and Scenes for Visualization
      To watch the solution develop, you open the plots for cylinder temperature and pressure. Additionally, you open the scene for fuel/air equivalence ratio and create a scene that displays the reaction progress variable. You write the scene to image files at regular intervals.
    - Running the Simulation
      The simulation is now set up and ready to run.
    - Analyzing the Results
      After the simulation is complete, you visualize the results.

Importing the Geometry

You start the simulation setup from a CAD geometry of the two-stroke engine in Parasolid format.

To import the geometry:

Start a double-precision version of Simcenter STAR-CCM+ and create a new simulation by clicking File > New.
In the Create a File dialog, select an appropriate parallel option and set Compute Processes to at least 32.
For information on the parallel options, see Process Options.
Click OK.
From the Simcenter STAR-CCM+ toolbar, click (Open Simcenter STAR-CCM+ In-Cylinder).
A Simcenter STAR-CCM+ In-cylinder tab opens within Simcenter STAR-CCM+.
Select File > Save As... and save the simulation under the name TwoStrokeEngine.sim.
Import the CAD geometry:
1. Right-click the Geometry node and select Import CAD Model.
2. In the Open dialog, navigate to the inCylinder folder of the downloaded tutorial files and select inCylinder_TwoStrokeEngineTutorial_Geometry.x_b.
3. Click Open.
4. Expand the Geometry manager node.
  A total of five parts are imported:
  - engine-fluid
  - exhaust-valve 1
  - gas-admission-plenum 1
  - gas-admission-plenum 2
  - intake-plenum
In the Graphics window, position the section to obtain a view similar to the one shown below.
Save the simulation .