Variable Mass
Variable mass.
blockType: Engee1DMechanical.Elements.Translational.VariableMass
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Path in the library: |
Description
Block Variable Mass simulates a variable mass. This unit can be used to simulate a fuel tank with a decreasing amount of fuel. The instantaneous mass value is sent to the input port at each time step during the entire simulation. To minimize solver errors, avoid discontinuities and sudden changes in the input signal.
When the mass of a component changes, the inertial force acting on this component also changes.:
where
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— the force of inertia;
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— variable mass;
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— the speed of the mass.
If the input mass value is lower than the minimum mass value specified in the Minimum mass parameter, the block performs its calculations for the minimum mass. The inertia force is calculated as:
where — minimum weight.
The amount of block movement remains constant. In the absence of external forces, a decrease in mass leads to an increase in speed. The amount of movement remains constant until an external force causes it to change.
Variables
Use the Initial Targets parameter group to set the priority and initial target values for the block parameter variables before modeling. For more information, see Configuring physical blocks using target values.
Ports
Conserving
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Flange
—
port connecting the unit to the network
translational mechanics
Details
A non-directional port that defines a time-varying mass transmission component.
| Program usage name |
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Input
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Mass
—
variable mass, kg
scalar
Details
The input port on which the mass value is received.
| Data types |
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| Complex numbers support |
No |
Parameters
Parameters
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Minimum mass —
minimum weight
kg | mg | g | t | lbm | oz | slug
Details
The minimum value that a variable mass can take during a simulation.
If the input mass value is lower than the minimum mass value, it is set equal to the minimum mass value.
| Units |
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| Default value |
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| Program usage name |
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| Evaluatable |
Yes |