Defining Flow-Driven Combined Motion

The motion flow-driven objects is affected by driving and resistive forces and torque.

The origins of such forces do not have to be included in the analysis model--they act on the object in a user-prescribed manner to either accelerate the object in its direction and angle travel or to slow it down.

In several places in this topic, the Direction Vector and the Direction of Rotation of the object are referenced. These are the directions specified on the Motion task dialog.

Note: Because the true direction of flow-driven motion is not always known prior to the analysis, this direction is really the Reference Positive Direction. Directions of driving and resistance forces are then relative to this direction.

Flow-driven objects may start off moving at a known velocity, and either speed up or slow down based on their interaction with the surrounding fluid (and applied forces).

To open the Motion Editor:

  1. On the Motion quick edit dialog, set the Type to Combined Linear/Angular. (If Flow-Driven is checked for both types of motion, then both types are flow-driven.)
  2. Click Edit... on the Edit Motion line.

To Define Flow-Driven Combined Motion

  1. Define each of the Linear properties by clicking on the desired property button: Initial Velocity, Driving Force, and Resistive Force. (It is not required to specify any or all of the properties.)
  2. For each property, select the Variation Method.
  3. Specify the appropriate values.
  4. Click the Apply button.
  5. Define each of the Angular properties by clicking on the desired property button: Initial Angular Velocity, Driving Torque, and Resistive Torque. (It is not required to specify any or all of the properties.)
  6. For each property, select the Variation Method.
  7. Enter the appropriate values.
  8. Click the Apply button.
  9. Click OK when all information is entered to close the dialog.

Variation Methods

Follow the links to learn more about the flow-driven linear and angular variation methods:

Flow Driven Linear Motion:

Flow Driven Angular Motion:

Parent topic: Combined Linear-Angular Motion