Engee documentation

Variable Rotational Damper

Rotational motion damper with variable damping coefficient.

variable rotational damper

Description

The Variable Rotational Damper block is a viscous rotational damper with a variable damping factor. The value of the variable damping coefficient is input to input port B. The magnitude of the damping torque is equal to the product of the value at port B and the relative angular velocity between the two non-directional rotation ports R and C. The minimum value of the damping ratio prevents non-physical negative values of the damping ratios.

The damping torque satisfies the following expression:

where

  • - torque transmitted through the damper;

  • - viscous damping coefficient;

  • - minimum permissible damping coefficient;

  • - is the relative angular velocity measured between two non-directional ports of rotation as follows: ;

  • - the angular velocity of the non-directional port of rotation R;

  • - angular velocity of the non-directional port of rotation C.

The unit applies equal opposite damping torques to the non-directional rotation ports. The sign of the damping torque acting on the R port is equal to the sign of the relative angular velocity. A positive relative angular velocity corresponds to a positive damping torque acting on the R port and a negative damping torque of the same magnitude acting on the C port.

Assumptions and limitations

  • The block represents viscous damping only.

  • The value of the damping coefficient must be greater than or equal to zero.

Ports

Conserving

# R — slave rotation port
`rotational mechanics

Details

A non-directional port of rotation associated with a slave element.

Program usage name

rod_flange

# C — basic rotation port
`rotational mechanics

Details

A non-directional port of rotation associated with the base element.

Program usage name

case_flange

Input

# B — variable damping factor
scalar

Details

Variable damping factor.

Data types

Float64.

Complex numbers support

No

Parameters

Parameters

# Minimum damping coefficient — minimum damping factor
N*m/(rad/s) | ft*lbf/(rad/s)

Details

The minimum permissible damping factor. If the value on port B is less than this value, it is equated to it. The value of this parameter must be greater than or equal to zero.

Values

N*m/(rad/s) | ft*lbf/(rad/s)

Default value

0.0 N*m/(rad/s)

Program usage name

C_min

Evaluatable

Yes