Check Valve 2 - MapleSim Help

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Check Valve 2

Check valve with continuous variable

Description

The Check Valve 2 (or Check Valve II) component allows fluid flow in one direction, from port A to port B.

This model uses a continuous-variable to model the change from open to closed. In the open-state the valve has a resistance given by ${R}_{\mathrm{open}}$. In the closed-state the valve has a conductance given by ${G}_{\mathrm{close}}$.

 Optional Volumes The boolean parameters Use volume A and Use volume B, when true, add optional volumes ${V}_{A}$  and ${V}_{B}$ to ports A and B, respectively. See Port Volumes for details. If two orifices or valves are connected, enabling a volume at the common port reduces the stiffness of the system and improves the solvability.
 Equations $\mathrm{closed}=\left(s<0\right)$ $p={p}_{A}-{p}_{B}=\left\{\begin{array}{cc}\frac{s}{{G}_{\mathrm{closed}}}& \mathrm{closed}\\ s& \mathrm{otherwise}\end{array}\phantom{\rule[-0.0ex]{5.0ex}{0.0ex}}q={q}_{A}-{q}_{\mathrm{VA}}=\left\{\begin{array}{cc}s& \mathrm{closed}\\ \frac{s}{{R}_{\mathrm{open}}}& \mathrm{otherwise}\end{array}$ ${V}_{{f}_{A}}=\left\{\begin{array}{cc}{V}_{A}\left(1+\frac{{p}_{A}}{\mathrm{El}}\right)& \mathrm{useVolumeA}\\ 0& \mathrm{otherwise}\end{array}\phantom{\rule[-0.0ex]{4.0ex}{0.0ex}}{V}_{{f}_{B}}=\left\{\begin{array}{cc}{V}_{B}\left(1+\frac{{p}_{B}}{\mathrm{El}}\right)& \mathrm{useVolumeB}\\ 0& \mathrm{otherwise}\end{array}$ ${q}_{{V}_{A}}=\left\{\begin{array}{cc}\frac{\mathrm{d}{V}_{{f}_{A}}}{\mathrm{d}t}& \mathrm{useVolumeA}\\ 0& \mathrm{otherwise}\end{array}\phantom{\rule[-0.0ex]{5.5ex}{0.0ex}}{q}_{{V}_{B}}=\left\{\begin{array}{cc}\frac{\mathrm{d}{V}_{{f}_{B}}}{\mathrm{d}t}& \mathrm{useVolumeB}\\ 0& \mathrm{otherwise}\end{array}$ ${q}_{A}+{q}_{B}-{q}_{\mathrm{VA}}-{q}_{\mathrm{VB}}=0$ ${q}_{\mathrm{summary}}=q\mathrm{flowScaleSummary}\phantom{\rule[-0.0ex]{7.5ex}{0.0ex}}{\mathrm{dp}}_{\mathrm{summary}}=p\mathrm{pressScaleSummary}$

Variables

 Name Units Description Modelica ID $p$ $\mathrm{Pa}$ Pressure drop from A to B p $q$ $\frac{{m}^{3}}{s}$ Flow rate from port A to port B q ${q}_{\mathrm{summary}}$ $\frac{{m}^{3}}{s}$ Internal flow sensor q_summary ${\mathrm{dp}}_{\mathrm{summary}}$ $\mathrm{Pa}$ Internal pressure difference sensor dp_summary ${V}_{{f}_{x}}$ ${m}^{3}$ Effective volume at port $x,x\in \left\{A,B\right\}$ Vfx ${q}_{{V}_{x}}$ $\frac{{m}^{3}}{s}$ Flow rate into effective volume at port $x,x\in \left\{A,B\right\}$ qVx

Connections

 Name Description Modelica ID $\mathrm{portA}$ Upstream hydraulic port portA $\mathrm{portB}$ Downstream hydraulic port portB

Parameters

General Parameters

 Name Default Units Description Modelica ID ${R}_{\mathrm{open}}$ $1·{10}^{-5}$ $\frac{\mathrm{Pa}s}{{m}^{3}}$ Open check valve resistance Ropen ${G}_{\mathrm{closed}}$ $1·{10}^{-5}$ $\frac{{m}^{3}}{\mathrm{Pa}s}$ Closed check valve conductance Gclosed Start closed $\mathrm{true}$ True initializes valve to closed, false to open Startclosed

Optional Volumes

 Name Default Units Description Modelica ID $\mathrm{useVolumeA}$ $\mathrm{false}$ True (checked) means a hydraulic volume chamber is added to portA useVolumeA ${V}_{A}$ $1·{10}^{-6}$ ${m}^{3}$ Volume of chamber A Va $\mathrm{useVolumeB}$ $\mathrm{false}$ True (checked) means a hydraulic volume chamber is added to portB useVolumeB ${V}_{B}$ $1·{10}^{-6}$ ${m}^{3}$ Volume of chamber B Vb

For more information see Port Volumes.

Fluid Parameters

The following parameters, used in the equations, are properties of the Hydraulic Fluid component used in the model.

 Name Units Description Modelica ID $\mathrm{\nu }$ $\frac{{m}^{2}}{s}$ Kinematic viscosity of fluid nu $\mathrm{\rho }$ $\frac{\mathrm{kg}}{{m}^{3}}$ Density of fluid rho $\mathrm{El}$ $\mathrm{Pa}$ Bulk modulus of fluid El

 See Also