Modeling the Propeller by Using the Virtual Disk Model

For this simulation, you model the effects of the propeller on the ship using the body force propeller method. This method belongs to the virtual disk model.

Using the virtual disk for a propeller requires you to define the following items:

  • dimensions and location of the disk

  • orientation of the disk axis. This orientation defines the direction of the thrust force.

  • propeller performance data, where the thrust coefficient K_T and the torque coefficient K_Q are provided as a function of advance ratio J

  • velocity plane on which to obtain an average velocity and density for the inflow surface of the virtual disk

To set up the virtual disk model:

  1. Right-click the Continua > Physics 1 > Models > Virtual Disk > Virtual Disks node and select New.
  2. Edit the Virtual Disk node and set Method to Body Force Propeller Method.
Before you can specify the propeller curve, you must import the propeller table data file (here in .csv format) into Simcenter STAR-CCM+.
  1. Right-click Tools > Tables and select New Table > File Table.
  2. Navigate to the motion folder of the downloaded tutorial files, select BSeries_Z5_BAR1p05_PD0p723.csv, and click Open.
You can now specify the propeller curve and set up the virtual disk. You set the Inflow Plane Radius to a value that is 10% larger than the virtual disk radius. The Inflow Plane Offset is 10% of the virtual disk diameter.
  1. Edit the Continua > Physics 1 > Virtual Disks > Virtual Disk node and set the following properties:
    Node Property Setting
    Propeller Curve Method Table (J)
    Table (J) Table BSeries_Z5_BAR1p05_PD0p723
    Table: J J
    Table: Kt KT
    Table: Kq KQ
    Table: Eta ETA
    Disk Geometry Inner Radius 0.036 m
    Outer Radius 0.18 m
    Origin [-6.307, 0.0, -1.25] m,m,m
    Normal And Coordinate System Coordinate System Laboratory -> Ship-CSys
    Disk Normal [1.0, 0.0, 0.0]
    Inflow Specification Method Inflow Velocity Plane
    Inflow Velocity Plane Inflow Plane Radius 0.198 m
    Inflow Plane Offset 0.036 m
    Induced Velocity Correction Option Induced Velocity Correction Off
    RotationRate (n) Rotation Rate 2300.0 rpm
    Note

    You must associate the Coordinate System property that defines the direction of thrust with the local coordinate system of the ship body, here identified as Ship-CSys. This association establishes the connection between the thrust produced by the virtual disk and the DFBI motion of the ship. The ship coordinate system moves with the ship according to the fluid forces calculated by the DFBI model.

  2. Expand the Tools > Coordinate Systems > Laboratory > Local Coordinate Systems and drag and drop the Virtual Disk-CSys 1 node into the currently active Geometry 1 scene.
    The virtual disk local coordinate system is displayed in the scene. The thrust produced by the virtual disk acts in the Z direction of this coordinate system.
  3. To visualize the virtual disk, select the Virtual Disk node within Physics Continuum 1 and zoom in on the virtual disk.


  4. Save the simulation.