modelThickEdgedOrifice

Thicked edged orifice flow model

Extends from Modelica.Fluid.Dissipation.Utilities.Icons.PressureLoss.Orifice_i (Icon for orifice), Modelica.Fluid.Interfaces.PartialPressureLoss (Base flow model for pressure loss functions with the same area at port_a and at port_b).

Information

This component models a thick edged orifice with sharp corners in the overall flow regime for incompressible and single-phase fluid flow through an arbitrary shaped cross sectional area (square, circular, etc.) considering influence of surface roughness. It is expected that also compressible fluid flow can be handled up to about Ma = 0.3. It is assumed that neither mass nor energy is stored in this component. In the model basically a function is called to compute the mass flow rate as a function of pressure loss for a thick edged orifice. Also the inverse of this function is defined, and a tool might use this inverse function instead, in order to avoid the solution of a nonlinear equation.

The details of the model are described in the documentation of the underlying function.

Parameters

TypeNameDefaultDescription
Modelica.Fluid.Fittings.BaseClasses.Orifices.ThickEdgedOrifice.GeometrygeometryGeometry of thick edged orifice
Assumptions
BooleanallowFlowReversal (from PartialTwoPort)system.allowFlowReversal= true to allow flow reversal, false restricts to design direction (port_a -> port_b)
Advanced
Medium.AbsolutePressuredp_start (from PartialTwoPortTransport)0.01*system.p_startGuess value of dp = port_a.p - port_b.p
Medium.MassFlowRatem_flow_start (from PartialTwoPortTransport)system.m_flow_startGuess value of m_flow = port_a.m_flow
Medium.MassFlowRatem_flow_small (from PartialTwoPortTransport)if system.use_eps_Re then system.eps_m_flow*system.m_flow_nominal else system.m_flow_smallSmall mass flow rate for regularization of zero flow
Advanced › Diagnostics
Booleanshow_T (from PartialTwoPortTransport)true= true, if temperatures at port_a and port_b are computed
Booleanshow_V_flow (from PartialTwoPortTransport)true= true, if volume flow rate at inflowing port is computed

Connectors

TypeNameDefaultDescription
Modelica.Fluid.Interfaces.FluidPort_aport_a (from PartialTwoPort)Fluid connector a (positive design flow direction is from port_a to port_b)
Modelica.Fluid.Interfaces.FluidPort_bport_b (from PartialTwoPort)Fluid connector b (positive design flow direction is from port_a to port_b)

Components

TypeNameDefaultDescription
Modelica.Fluid.Systemsystem (from PartialTwoPort)System wide properties
Medium.MassFlowRatem_flow (from PartialTwoPortTransport)Mass flow rate in design flow direction
SI.Pressuredp (from PartialTwoPortTransport)Pressure difference between port_a and port_b (= port_a.p - port_b.p)
SI.VolumeFlowRateV_flow (from PartialTwoPortTransport)m_flow/Modelica.Fluid.Utilities.regStep(m_flow, Medium.density(state_a), Medium.density(state_b), m_flow_small)Volume flow rate at inflowing port (positive when flow from port_a to port_b)
Medium.Temperatureport_a_T (from PartialTwoPortTransport)Modelica.Fluid.Utilities.regStep(port_a.m_flow, Medium.temperature(state_a), Medium.temperature(Medium.setState_phX(port_a.p, port_a.h_outflow, port_a.Xi_outflow)), m_flow_small)Temperature close to port_a, if show_T = true
Medium.Temperatureport_b_T (from PartialTwoPortTransport)Modelica.Fluid.Utilities.regStep(port_b.m_flow, Medium.temperature(state_b), Medium.temperature(Medium.setState_phX(port_b.p, port_b.h_outflow, port_b.Xi_outflow)), m_flow_small)Temperature close to port_b, if show_T = true