Defining the Physics Continua and Motion

To prepare the simulation for RBA, activate the Rotor Blade Aeroelasticity model in the relevant physics continua, and define the motion of the rotor blades.

To model the rotor blade aeroelasticity, you require two physics continua. One physics continuum models the fluid physics in Simcenter STAR-CCM+. The other physics continuum represents the beams that are modeled externally and imported in Simcenter STAR-CCM+ as data files. In both continua, you activate the Rotor Blade Aeroelasticity model.
  1. Create the background and overset fluid regions as described within Rotor Blade Aeroelasticity.
  2. For these regions, create a physics continuum and select the models that describe the physics of the fluid. To model RBA, add the following models to the fluid continuum:
    Group Box Model
    Optional Models Co-Simulation
    Co-Simulation Models Rotor Blade Aeroelasticity
  3. Create a new physics continuum for the external data with the following models:
    Group Box Model
    Optional Models

    External Continuum

    External Application (selected automatically)
    External Application Rotor Blade Aeroelasticity
    Space Three Dimensional (selected automatically)
    Time Implicit Unsteady (selected automatically)
    When you create the external physics continuum, Simcenter STAR-CCM+ adds a link node under the External Links node:

    This link allows you to define the connection between the external input files and the internal Simcenter STAR-CCM+ simulation.
    • If you wish to model multiple rotors within the same fluid domain, create additional links under the External Links node. You require a link for each rotor.
To account for the motion of the blades, you use two motion models—rotation and morphing. The rotation motion accounts for the rigid rotation of the blades. The morphing motion adjusts the fluid mesh based on the rigid rotation and the imported blade deformation.

To define the rotation motion you require two coordinate systems: a coordinate system that rotates with the rotor (a managed coordinate system), and a stationary coordinate system. You can use the default laboratory coordinate system for the stationary coordinate system.

  1. Create a rotation motion for the rotor:
    1. Create a new local cartesian coordinate system, [Cartesian 1], under the Coordinate Systems > Laboratory > Local Coordinate Systems node.
    2. Create a new rotation motion and set its properties as follows:
      Node Property Value
      Rotation Axis Direction Set direction to the axis about which the rotor is rotating. For example, if the rotor is rotating about the Z-axis, set Axis Direction as [0.0, 0.0, 1.0].
      Managed Coordinate System Laboratory > [Cartesian 1]
      Rotation Rate Rotation Rate Allows you to specify an angular velocity for the rotor.
  2. Create a morphing motion, [Morphing], and select either RBF or BSpline for Morpher Method.
The blade boundaries deform based on the total displacment. The displacement has a rigid component (the rotation) and a non-rigid component (the beam deformation). For such cases, activate the Linear Fitter.
  1. Select the [Morphing] > [morpher method] Parameters node and activate Linear Fitter.