Operating Parameters

The operating parameters pertaining to the Bent Axis Piston template involve the time definition for the simulation, pump configuration and angular velocity definitions for pump rotation (see, Figure 6.468).

Figure 6.468 - Bent axis piston model-Operating parameters

Time Definition

This provides the following ways to specify the size and number of time steps for the Bent Axis Piston pump simulation (see Figure 6.468):

Revolutions: A single revolution corresponds to a pump rotation of 360 degrees. The parameters required under the Time Definition of Revolutions are:

Number of Revolutions: The number of pump revolutions to be simulated.
Time Steps Per Piston Rotation: The number of time steps taken to move a piston through one pocket.

The magnitude of the time-step size (s) and the angle of rotation (deg) depends on the Time Steps Per Piston Rotation and the Number of Pistons.

	6.42
	6.43

For a Time Definition of Revolutions, the Number of Time Steps is computed as follows:

6.44

Pockets: A method of Time Definition that uses the angle from one piston to the next to determine the size and Number of Time Steps. A single Pocket corresponds to a rotation equal to the average angle between pistons, based on 360 deg divided by the user specified Number of Pistons. The parameters required under the Time Definition of Pockets are:

Number of Pockets: The amount of rotation based on the angle between two pistons.
Time Steps Per Piston Rotation: The number of time steps taken to move a piston through one pocket.

Figure 6.469 - Pocket-Pistons

For a Time Definition of Pockets, the Number of Time Steps is computed as follows :

6.45

Total Time Steps: Total number of time steps for a given simulation. The parameter required under Total Time Steps is:

Time Steps Per Piston Rotation
Number of Time Steps (in the Simulation Panel)

For a Time Definition of Total Time Steps, the Simulation Time (Duration) is computed as follows:

6.46

	Note: If the Number of Time Steps is displayed in Blue, it means that it is set and controlled elsewhere and cannot be changed in the Simulation Panel.
	Note: The setting of the Time Definition in the Model Tab of the Properties Panel and in the Simulation Panel are slaved to each other, such that changing the value in one panel, changes the value in the other.
	Note: If multiple templates are active, the Bent Axis Piston Pump must be set as the Reference Pump for the Time Definition option to be displayed.

Pump Configuration

This contains the parameters pertaining to the geometry of the bent axis piston pump (see, Figure 6.468). The inputs such as Number of Pistons, Flange Center to Ball Joint Radius, Flange Center and Flange Axis Vector are same as those defined in the Bent Axis Piston mesher.

Cylinder Block Axis Vector: This is the vector aligned with the axis of rotation of the cylinder block in the laboratory reference frame at a given operating angle. Specify the axis of direction in

co-ordinates.

Figure 6.470 - Cylinder block axis vector schematic: Non-articulating

Figure 6.471 - Cylinder block axis vector schematic: Articulating

Note: For multiple pumps connected by a common port, the Cylinder Block Axis Vector is not specified in terms of the alignment the cylinder during operation but must instead be specified with an additional rotation to compensate for the subsequent coordinate rotation.

Distance From Bent Center to Flange Center: This is the distance between the bent center (joint) and center of the rotating flange that contain the sockets for the ball joints.

Figure 6.472 - Distance between Bent center to Flange center

Angular Velocity Definition

This contains parameters pertaining to the rotation of the pump. The parameters defined under the Angular Velocity Definition are: Rotational Direction and Rotational Speed (see ).

The Rotational Direction is specified as Clockwise or Counterclockwise relative to the Flange Axis Vector, using the convention that a positive clockwise rotation is based on the vantage point with the Flange Axis Vector pointing at an observer. Rotational Speed(given in rpm) denotes the speed of Bent Axis Piston rotation.

Figure 6.473 - Angular velocity definition

Note: The magnitude of the Rotational Speed is specified relative to the stationary (lab) frame of reference in terms of rpm, even for example, when applied to the boundary of a non-inertial reference frame. The Rotational Speed only accepts a positive value, unless the Rotational Direction is set to Both Directions. Actually it follows the right-hand thumb rule with the thumb aligned with the flange axis.