WOLFRAM SYSTEM MODELER
LocalPipeFlowHeatTransferLocalPipeFlowHeatTransfer: Laminar and turbulent forced convection in pipes, local coefficients |
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Wolfram Language
In[1]:=
SystemModel["Modelica.Fluid.Pipes.BaseClasses.HeatTransfer.LocalPipeFlowHeatTransfer"]
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Information
This information is part of the Modelica Standard Library maintained by the Modelica Association.
Heat transfer model for laminar and turbulent flow in pipes. Range of validity:
- fully developed pipe flow
- forced convection
- one phase Newtonian fluid
- (spatial) constant wall temperature in the laminar region
- 0 ≤ Re ≤ 1e6, 0.6 ≤ Pr ≤ 100, d/L ≤ 1
- The correlation holds for non-circular pipes only in the turbulent region. Use diameter=4*crossArea/perimeter as characteristic length.
The correlation takes into account the spatial position along the pipe flow, which changes discontinuously at flow reversal. However, the heat transfer coefficient itself is continuous around zero flow rate, but not its derivative.
References
- Verein Deutscher Ingenieure (1997):
- VDI Wärmeatlas. Springer Verlag, Ed. 8, 1997.
Parameters (6)
| n |
Value: 1 Type: Integer Description: Number of heat transfer segments |
|---|---|
| use_k |
Value: false Type: Boolean Description: = true to use k value for thermal isolation |
| k |
Value: 0 Type: CoefficientOfHeatTransfer (W/(m²⋅K)) Description: Heat transfer coefficient to ambient |
| T_ambient |
Value: system.T_ambient Type: Temperature (K) Description: Ambient temperature |
| nParallel |
Value: Type: Real Description: Number of identical parallel flow devices |
| alpha0 |
Value: 100 Type: CoefficientOfHeatTransfer (W/(m²⋅K)) Description: Guess value for heat transfer coefficients |
Inputs (6)
| states |
Type: ThermodynamicState[n] Description: Thermodynamic states of flow segments |
|---|---|
| surfaceAreas |
Type: Area[n] (m²) Description: Heat transfer areas |
| vs |
Type: Velocity[n] (m/s) Description: Mean velocities of fluid flow in segments |
| lengths |
Type: Length[n] (m) Description: Lengths along flow path |
| dimensions |
Type: Length[n] (m) Description: Characteristic dimensions for fluid flow (diameter for pipe flow) |
| roughnesses |
Type: Roughness[n] (m) Description: Average heights of surface asperities |
Outputs (1)
| Q_flows |
Type: HeatFlowRate[n] (W) Description: Heat flow rates |
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Connectors (1)
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heatPorts |
Type: HeatPorts_a[n] Description: Heat port to component boundary |
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Components (2)
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states |
Type: ThermodynamicState[n] Description: Thermodynamic states of flow segments |
|---|---|---|
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system |
Type: System Description: System wide properties |