WOLFRAM SYSTEM MODELER
FlowModelWall friction, gravity, momentum flow |
SystemModel["Modelica.Fluid.Pipes.BaseClasses.PartialStraightPipe.FlowModel"]
m |
Value: n - 1 Type: Integer Description: Number of flow segments |
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n |
Value: 2 Type: Integer Description: Number of discrete flow volumes |
nParallel |
Value: Type: Real Description: Number of identical parallel flow devices |
g |
Value: system.g Type: Acceleration (m/s²) Description: Constant gravity acceleration |
allowFlowReversal |
Value: system.allowFlowReversal Type: Boolean Description: = true, if flow reversal is enabled, otherwise restrict flow to design direction (states[1] -> states[n+1]) |
momentumDynamics |
Value: system.momentumDynamics Type: Dynamics Description: Formulation of momentum balance |
m_flow_start |
Value: system.m_flow_start Type: MassFlowRate (kg/s) Description: Start value of mass flow rates |
p_a_start |
Value: Type: AbsolutePressure (Pa) Description: Start value for p[1] at design inflow |
p_b_start |
Value: Type: AbsolutePressure (Pa) Description: Start value for p[n+1] at design outflow |
useUpstreamScheme |
Value: true Type: Boolean Description: = false to average upstream and downstream properties across flow segments |
use_Ib_flows |
Value: momentumDynamics <> Types.Dynamics.SteadyState Type: Boolean Description: = true to consider differences in flow of momentum through boundaries |
Re_turbulent |
Value: 4000 Type: ReynoldsNumber Description: Start of turbulent regime, depending on type of flow device |
show_Res |
Value: false Type: Boolean Description: = true, if Reynolds numbers are included for plotting |
from_dp |
Value: momentumDynamics >= Types.Dynamics.SteadyStateInitial Type: Boolean Description: = true, use m_flow = f(dp), otherwise dp = f(m_flow) |
dp_nominal |
Value: Type: AbsolutePressure (Pa) Description: Nominal pressure loss (only for nominal models) |
m_flow_nominal |
Value: if system.use_eps_Re then system.m_flow_nominal else 1e2 * m_flow_small Type: MassFlowRate (kg/s) Description: Nominal mass flow rate |
m_flow_small |
Value: if system.use_eps_Re then system.eps_m_flow * m_flow_nominal else system.m_flow_small Type: MassFlowRate (kg/s) Description: Within regularization if |m_flows| < m_flow_small (may be wider for large discontinuities in static head) |
pathLengths |
Type: Length[m] (m) Description: Lengths along flow path |
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states |
Type: ThermodynamicState[n] Description: Thermodynamic states along design flow |
vs |
Type: Velocity[n] (m/s) Description: Mean velocities of fluid flow |
crossAreas |
Type: Area[n] (m²) Description: Cross flow areas at segment boundaries |
dimensions |
Type: Length[n] (m) Description: Characteristic dimensions for fluid flow (diameters for pipe flow) |
roughnesses |
Type: Roughness[n] (m) Description: Average height of surface asperities |
dheights |
Type: Length[n - 1] (m) Description: Height(states[2:n]) - Height(states[1:n-1]) |
pathLengths_internal |
Default Value: pathLengths Type: Length[n - 1] (m) Description: pathLengths used internally; to be defined by extending class |
Res_turbulent_internal |
Default Value: Re_turbulent * ones(n - 1) Type: ReynoldsNumber[n - 1] Description: Re_turbulent used internally; to be defined by extending class |
system |
Type: System Description: System properties |
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states |
Type: ThermodynamicState[n] Description: Thermodynamic states along design flow |
Modelica.Fluid.Pipes Basic pipe flow model without storage of mass or energy |