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# ParasiticVolume

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# ParasiticVolume

## Library

Iconic Diagrams\Hydraulic\Volumes

## Use

Domains: Continuous. Size: 1-D. Kind: Iconic Diagrams (Hydraulics).

## Description

This model represents a tiny volume (default: 1 ml) if the causality of the port is pressure out, and a zero flow, if the causality is flow out:

 • Pressure out: Volume of 1 ml
 • Flow out: flow source with 0 {m3/s} flow.

A parasitic volume is a tiny volume that can be added to elements to make them more easy to simulate. Some elements require a pressure as input variable. Coupling two such elements leads to a mathematical problem: both yield a volume flow as function of the input pressure. Adding a parasitic volume in between will solve the mathematical problem (the parasitic volume calculates the pressure) without changing the dynamics much (the volume is small).

The parasitic element has a likes causality. If two parasitic volumes are coupled, one of them will get a pressure out causality (representing a tiny volume) and the other will get a flow out causuality (representing a zero flow). I.e only one of them is a volume and the other becomes ineffective.

Note:  If you want an element to have a specific volume, do not use the parasitic volume! In case of a flow out causality it will be replaced by a 0 flow (e.g. ero volume). Use the volume element instead.

## Interface

 Ports Description p Causality likes pressure out Parameters (hidden) V B p_initial Volume of oil under pressure [m3] Effective bulk modulus [Pa] The starting pressure of the volume [Pa]