Ori Poly $—$ Orifice model using a polynomial approach with volumes at the ports

The Ori Poly component describes the laminar/turbulent flow through an orifice using a polynomial approach. The mass and flow forces are not included. Use the modifier(s)

VolumeA(port_A(p(start=1e5,fixed=true)))

and/or

VolumeB(port_A(p(start=1e5,fixed=true)))

to set the initial condition(s) for the pressure of the lumped volume(s) [$\mathrm{Pa}$].

Related Components

 Name Description Resistance with laminar flow and volumes at the ports. Recommended component. The component, based on the loss coefficient K, describes both flow regimes: laminar for very small Reynolds numbers and turbulent for higher Reynolds numbers (default model). Orifice component checking for cavitation. Simple textbook component, using a constant discharge coefficient. It is valid for turbulent flow only; severe numerical problems for laminar flow. Metering Orifice (that is, component Orifice No States with variable diameter). Two orifices in series, one with variable the other with fixed flow area. Differences between basic models are shown by a figure.

Connections

 Name Description Modelica ID ${\mathrm{port}}_{A}$ Layout of port where oil flows into an element ($0<{m}_{\mathrm{flow}}$, ${p}_{B}<{p}_{A}$ means $0<\mathrm{Δp}$) port_A ${\mathrm{port}}_{B}$ Hydraulic port where oil leaves the component (${m}_{\mathrm{flow}}<0$, ${p}_{B}<{p}_{A}$ means $0<\mathrm{Δp}$) port_B $\mathrm{oil}$ oil

Parameters

 Name Default Units Description Modelica ID ${\mathrm{ΔT}}_{\mathrm{system}}$ $0$ $K$ Temperature offset from system temperature dT_system use volume A $\mathrm{true}$ If true, a volume is present at port_A useVolumeA use volume B $\mathrm{true}$ If true, a volume is present at port_B useVolumeB ${V}_{A}$ ${10}^{-6}$ ${m}^{3}$ Geometric volume at port A volumeA ${V}_{B}$ ${10}^{-6}$ ${m}^{3}$ Geometric volume at port B volumeB $d$ $0.001$ $m$ Orifice diameter diameter ${c}_{\mathrm{turb}}$ $0.707$ Discharge coefficient cturb ${k}_{1}$ $10$ Laminar part k1 ${k}_{2}$ $2$ ${k}_{2}=\frac{1}{{C}_{d}^{2}}$ k2 $G$ $1.53·{10}^{-11}$ $\frac{{m}^{3}}{s\mathrm{Pa}}$ Hydraulic conductance $G=\frac{\mathrm{∂q}}{\mathrm{∂p}}$ G ${p}_{\mathrm{trans}}$ [1] $\mathrm{Pa}$ Transition pressure p_trans ${\Re }_{\mathrm{trans}}$ $100$ $1$ Transition Reynolds number Re_trans $\mathrm{Transition}$ $2$ Transition model Transition reg type $3$ Regularization type regtype reg param $3$ Regularization parameter regparam

[1] $\frac{9{\Re }_{\mathrm{trans}}^{2}\mathrm{oil.density}\left(\mathrm{oil.p0},\mathrm{oil.T0}\right){\mathrm{oil.kinematicViscosity}\left(\mathrm{oil.p0},\mathrm{oil.T0}\right)}^{2}}{8{c}_{\mathrm{turb}}^{2}{d}^{2}}$