modelWallFriction
Pressure drop in pipe due to wall friction (only for test purposes; if needed use Pipes.StaticPipe instead)
Extends from Modelica.Fluid.Fittings.BaseClasses.QuadraticTurbulent.BaseModel (Generic pressure drop component with constant turbulent loss factor data and without an icon).
Information
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| LossFactorData | data (from BaseModel) | Loss factor data | |
| SI.Length | length | Length of pipe | |
| SI.Diameter | diameter | Inner diameter of pipe | |
| Modelica.Fluid.Types.Roughness | roughness | Absolute roughness of pipe (> 0 required, details see info layer) | |
| Assumptions | |||
| Boolean | allowFlowReversal (from PartialTwoPort) | system.allowFlowReversal | = true to allow flow reversal, false restricts to design direction (port_a -> port_b) |
| Advanced | |||
| Medium.AbsolutePressure | dp_start (from PartialTwoPortTransport) | 0.01*system.p_start | Guess value of dp = port_a.p - port_b.p |
| Medium.MassFlowRate | m_flow_start (from PartialTwoPortTransport) | system.m_flow_start | Guess value of m_flow = port_a.m_flow |
| Medium.MassFlowRate | m_flow_small (from PartialTwoPortTransport) | if system.use_eps_Re then system.eps_m_flow*system.m_flow_nominal else system.m_flow_small | Small mass flow rate for regularization of zero flow |
| Boolean | use_Re (from BaseModel) | system.use_eps_Re | = true, if turbulent region is defined by Re, otherwise by m_flow_small |
| Boolean | from_dp (from BaseModel) | true | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Advanced › Diagnostics | |||
| Boolean | show_T (from PartialTwoPortTransport) | true | = true, if temperatures at port_a and port_b are computed |
| Boolean | show_V_flow (from PartialTwoPortTransport) | true | = true, if volume flow rate at inflowing port is computed |
| Boolean | show_Re (from BaseModel) | false | = true, if Reynolds number is included for plotting |
| Assumptions › Dynamics | |||
| Modelica.Fluid.Types.Dynamics | momentumDynamics (from PartialLumpedFlow) | system.momentumDynamics | Formulation of momentum balance |
| Nominal operating point | |||
| SI.MassFlowRate | m_flow_nominal (from BaseModel) | if system.use_eps_Re then system.m_flow_nominal else 1e2*system.m_flow_small | Nominal mass flow rate |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Fluid.Interfaces.FluidPort_a | port_a (from PartialTwoPort) | Fluid connector a (positive design flow direction is from port_a to port_b) | |
| Modelica.Fluid.Interfaces.FluidPort_b | port_b (from PartialTwoPort) | Fluid connector b (positive design flow direction is from port_a to port_b) |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Fluid.System | system (from PartialTwoPort) | System wide properties | |
| Medium.MassFlowRate | m_flow (from PartialTwoPortTransport) | Mass flow rate in design flow direction | |
| SI.Pressure | dp (from PartialTwoPortTransport) | Pressure difference between port_a and port_b (= port_a.p - port_b.p) | |
| SI.VolumeFlowRate | V_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.Temperature | port_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.Temperature | port_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 |
| SI.Length | pathLength (from PartialLumpedFlow) | Length flow path | |
| SI.Momentum | I (from PartialLumpedFlow) | Momenta of flow segments | |
| SI.Force | Ib_flow (from PartialLumpedFlow) | Flow of momentum across boundaries | |
| SI.Force | F_p (from PartialLumpedFlow) | Pressure force | |
| SI.Force | F_fg (from PartialLumpedFlow) | Friction and gravity force | |
| SI.ReynoldsNumber | Re (from BaseModel) | Modelica.Fluid.Pipes.BaseClasses.CharacteristicNumbers.ReynoldsNumber_m_flow(m_flow, noEvent(if m_flow > 0 then Medium.dynamicViscosity(state_a) else Medium.dynamicViscosity(state_b)), data.D_Re) | Reynolds number at diameter data.D_Re |
| SI.Pressure | dp_fg (from BaseModel) | Pressure loss due to friction and gravity | |
| SI.Area | A_mean (from BaseModel) | Modelica.Constants.pi/4*(data.diameter_a^2 + data.diameter_b^2)/2 | Mean cross flow area |