NominalLaminarFlowNominalLaminarFlow: Linear laminar flow for given nominal values 
This information is part of the Modelica Standard Library maintained by the Modelica Association.
This model defines a simple linear pressure loss assuming laminar flow for
specified dp_nominal
and m_flow_nominal
.
Select show_Res = true
to analyze the actual flow and the lengths of a pipe that would fulfill the
specified nominal values for given geometry parameters crossAreas
, dimensions
and roughnesses
.
m 
Value: n  1 Type: Integer Description: Number of flow segments 

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 to allow flow reversal, false restricts 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 
dp_nominal 
Value: Type: AbsolutePressure (Pa) Description: Nominal pressure loss 
m_flow_nominal 
Value: Type: MassFlowRate (kg/s) Description: Mass flow rate for dp_nominal 
pathLengths 
Type: Length[m] (m) Description: Lengths along flow path 

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:n1]) 
system 
Type: System Description: System properties 


states 
Type: ThermodynamicState[n] Description: Thermodynamic states along design flow 