Check Valve

 Description The Check Valve component allows fluid flow in one direction, from port A to port B. The flow is controlled by an adjustable orifice whose area is controlled by the pressure difference from port A to port B. The area increases linearly from ${A}_{\mathrm{close}}$ to ${A}_{\mathrm{open}}$ as the pressure increases from ${p}_{\mathrm{close}}$ to ${p}_{\mathrm{open}}$. The pressure drop vs flow-rate, for the computed area, comes from the Orifice model.
 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 the stiffness of the system and improves the solvability.
 Equations $p={p}_{A}-{p}_{B}=\mathrm{\pi }\mathrm{\rho }\mathrm{\nu }q\frac{{\left(\frac{16{q}^{4}}{{\mathrm{\pi }}^{2}{A}_{\mathrm{cs}}^{2}{\mathrm{\nu }}^{4}}+{\mathrm{\Re }}_{\mathrm{Cr}}^{4}\right)}^{\frac{1}{4}}}{4{C}_{d}^{2}\sqrt{\mathrm{\pi }{A}_{\mathrm{cs}}}{A}_{\mathrm{cs}}}$ $q={q}_{A}-{q}_{{V}_{A}}$ $\left\{\begin{array}{cc}\left\{{A}_{\mathrm{cs}}={A}_{i}={A}_{t}\right\}& \mathrm{Exact}\\ \left\{{A}_{\mathrm{cs}}=\mathrm{min}\left({A}_{\mathrm{open}},\mathrm{max}\left({A}_{\mathrm{close}},{A}_{i}\right)\right),{t}_{c}\frac{\mathrm{d}{A}_{i}}{\mathrm{d}t}+{A}_{i}={A}_{t}\right\}& \mathrm{otherwise}\end{array}$ ${A}_{t}=\left\{\begin{array}{cc}{A}_{\mathrm{close}}& p\le {p}_{\mathrm{close}}\\ {A}_{\mathrm{close}}+\left(p-{p}_{\mathrm{close}}\right)\frac{{A}_{\mathrm{open}}-{A}_{\mathrm{close}}}{{p}_{\mathrm{open}}-{p}_{\mathrm{close}}}& p<{p}_{\mathrm{open}}\\ {A}_{\mathrm{open}}& \mathrm{otherwise}\end{array}$ ${V}_{{f}_{A}}=\left\{\begin{array}{cc}{V}_{A}\left(1+\frac{{p}_{A}}{\mathrm{El}}\right)& \mathrm{useVolumeA}\\ 0& \mathrm{otherwise}\end{array}\phantom{\rule[-0.0ex]{4.5ex}{0.0ex}}{V}_{{f}_{B}}=\left\{\begin{array}{cc}{V}_{B}\left(1+\frac{{p}_{B}}{\mathrm{El}}\right)& \mathrm{useVolumeB}\\ 0& \mathrm{otherwise}\end{array}$ ${q}_{{V}_{A}}=\left\{\begin{array}{cc}\frac{\mathrm{d}{V}_{{f}_{A}}}{\mathrm{d}t}& \mathrm{useVolumeA}\\ 0& \mathrm{otherwise}\end{array}\phantom{\rule[-0.0ex]{6.0ex}{0.0ex}}{q}_{{V}_{B}}=\left\{\begin{array}{cc}\frac{\mathrm{d}{V}_{{f}_{B}}}{\mathrm{d}t}& \mathrm{useVolumeB}\\ 0& \mathrm{otherwise}\end{array}$ ${q}_{A}+{q}_{B}-{q}_{{V}_{A}}-{q}_{{V}_{B}}=0$

Variables

 Name Units Description Modelica ID $p$ $\mathrm{Pa}$ Pressure drop from A to B p ${A}_{i}$ ${m}^{2}$ Filtered  interpolated area At ${A}_{t}$ ${m}^{2}$ Interpolated area At $q$ $\frac{{m}^{3}}{s}$ Flow rate from port A to port B q

Connections

 Name Description Modelica ID $\mathrm{portA}$ Hydraulic port on left side portA $\mathrm{portB}$ Hydraulic port on right side portB

Parameters

General Parameters

 Name Default Units Description Modelica ID ${p}_{\mathrm{close}}$ $1.9·{10}^{7}$ $\mathrm{Pa}$ Pressure at which valve is fully closed (A = Aclose) pclose ${p}_{\mathrm{open}}$ $2.05·{10}^{7}$ $\mathrm{Pa}$ Pressure at which valve is fully open (A = Aopen) popen ${A}_{\mathrm{close}}$ $1·{10}^{-12}$ ${m}^{2}$ Valve area when closed (leakage) Aclose ${A}_{\mathrm{open}}$ $1·{10}^{-5}$ ${m}^{2}$ Valve area when fully open Aopen $\mathrm{Exact}$ $\mathrm{false}$ When false (not checked) a first-order dynamics is used for the valve area Exact ${t}_{c}$ $\frac{1}{10}$ $s$ Time constant of dynamics equation used when Exact is false tc ${C}_{d}$ $\frac{7}{10}$ Flow-discharge coefficient Cd ${\mathrm{\Re }}_{\mathrm{Cr}}$ $12$ Reynolds number at critical flow ReCr

Volume Parameters

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