Template: TwoPortComponentSignalInput

The TwoPortComponentSignalInput template is a partial model of a two-port hydraulic component with a signal input.  The two hydraulic ports are A and B, the dimensionless signal input is u. A typical use for this template is to create a varying restriction, with the restriction set by the input signal.

There is no storage element in this class, that is, the mass flow into port A equals the mass flow out of port B.

The pressure differential across the component, $\mathrm{Δp}$, is typically ${p}_{A}-{p}_{B}$, but if either pressure is less than the vapour pressure of the oil, then the vapour pressure is used to compute $\mathrm{Δp}$.

Variables

 Name Value Units Description Modelica ID ${p}_{A}$ $\mathrm{Pa}$ pressure at port A port_A.p ${p}_{B}$ $\mathrm{Pa}$ pressure at port B port_B.p ${p}_{A\left(\mathrm{abs}\right)}$ ${p}_{A}+{p}_{\mathrm{oil}\left(\mathrm{atm}\right)}$ $\mathrm{Pa}$ absolute pressure at port A pA_abs ${p}_{B\left(\mathrm{abs}\right)}$ ${p}_{B}+{p}_{\mathrm{oil}\left(\mathrm{atm}\right)}$ $\mathrm{Pa}$ absolute pressure at port B pB_abs ${p}_{A\left(\mathrm{lim}\right)}$ $\mathrm{max}\left({p}_{A},{p}_{\mathrm{oil}\left(\mathrm{vapour}\right)}-{p}_{\mathrm{oil}\left(\mathrm{atm}\right)}\right)$ $\mathrm{Pa}$ limited gauge pressure at port A pA_limited ${p}_{B\left(\mathrm{lim}\right)}$ $\mathrm{max}\left({p}_{B},{p}_{\mathrm{oil}\left(\mathrm{vapour}\right)}-{p}_{\mathrm{oil}\left(\mathrm{atm}\right)}\right)$ $\mathrm{Pa}$ limited gauge pressure at port B pB_limited ${p}_{A\left(\mathrm{sum}\right)}$ ${p}_{A}$ $\mathrm{Pa}$ pressure at port A summary_pA ${p}_{B\left(\mathrm{sum}\right)}$ ${p}_{B}$ $\mathrm{Pa}$ pressure at port B summary_pB $\mathrm{Δp}$ ${p}_{A\left(\mathrm{lim}\right)}-{p}_{B\left(\mathrm{lim}\right)}$ $\mathrm{Pa}$ pressure differential dp ${p}_{\mathrm{sat}}$ $\mathrm{oil.gasSaturationPressure}\left(T,\mathrm{oil.v_gas}\right)$ $\mathrm{Pa}$ gas saturation pressure p_sat ${m}_{\mathrm{flow}\left(A\right)}$ $\frac{\mathrm{kg}}{s}$ mass flow rate at port A; positive if oil is entering the component. port_A.m_flow ${m}_{\mathrm{flow}\left(B\right)}$ $-{m}_{\mathrm{flow}\left(A\right)}$ $\frac{\mathrm{kg}}{s}$ mass flow rate at port B; positive if oil is entering the component. port_B.m_flow ${\mathrm{HP}}_{\mathrm{sum}}$ $-\mathrm{Δp}q$ $W$ hydraulic power summary_HP $q$ $\frac{{m}_{\mathrm{flow}\left(A\right)}}{\mathrm{\rho }}$ $\frac{{m}^{3}}{s}$ volume flow rate into port A q ${q}_{\mathrm{sum}}$ $q$ $\frac{{m}^{3}}{s}$ volume flow rate into port A summary_q $\mathrm{\rho }$ $\mathrm{\rho }\left(\mathrm{Δp},{p}_{A\left(\mathrm{abs}\right)},{p}_{B\left(\mathrm{abs}\right)},T,\mathrm{oil}\right)$ $\frac{\mathrm{kg}}{{m}^{3}}$ upstream density of oil rho $\mathrm{\nu }$ $\mathrm{\nu }\left(\mathrm{Δp},{p}_{A\left(\mathrm{abs}\right)},{p}_{B\left(\mathrm{abs}\right)},T,\mathrm{oil}\right)$ $\frac{{m}^{2}}{s}$ upstream kinematic viscosity of oil nu $T$ ${T}_{\mathrm{oil}\left(0\right)}+{\mathrm{ΔT}}_{\mathrm{system}}$ $K$ local temperature of oil T

Parameters

 Name Default Units Description Modelica ID ${\mathrm{ΔT}}_{\mathrm{system}}$ 0 $K$ temperature offset from system temperature dT_system

 Assumptions No storage of energy or mass in the component.
 Sign Conventions If the pressure at port A is greater than the pressure at port B, the volume flow rate at port A is positive.