Engee documentation

Variable Rotational Damper

Rotary motion damper with variable damping coefficient.

blockType: Engee1DMechanical.Elements.Rotational.VariableDamper

variable rotational damper

Path in the library:

/Physical Modeling/1D Mechanical/Couplings & Drives/Springs & Dampers/Variable Rotational Damper

Description

Block Variable Rotational Damper It is a viscous rotary motion damper with a variable damping coefficient. The value of the variable damping coefficient is sent to the input port B. The magnitude of the damping moment is equal to the product of the value at port B and the relative angular velocity between the two non-directional ports of rotation R and C. The minimum value of the damping coefficient prevents the occurrence of non-physical negative values of the damping coefficients.

The damping torque satisfies the following expression:

where

  • — the torque transmitted through the damper;

  • — coefficient of viscous damping;

  • — the minimum allowable damping coefficient;

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

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

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

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

Assumptions and limitations

  • The block represents only viscous damping.

  • 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.

Units

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

0.0 N*m/(rad/s)
Program usage name

C_min
Evaluatable

Yes