WOLFRAM SYSTEM MODELER
ReynoldsNumberReturn Reynolds number from v, rho, mu, D |
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Wolfram Language
In[1]:=
SystemModel["Modelica.Fluid.Pipes.BaseClasses.CharacteristicNumbers.ReynoldsNumber"]
Out[1]:=
Information
This information is part of the Modelica Standard Library maintained by the Modelica Association.
Calculation of Reynolds Number
Re = |v|ρD/μ
a measure of the relationship between inertial forces (vρ) and viscous forces (D/μ).
The following table gives examples for the characteristic dimension D and the velocity v for different fluid flow devices:
| Device Type | Characteristic Dimension D | Velocity v |
|---|---|---|
| Circular Pipe | diameter | m_flow/ρ/crossArea |
| Rectangular Duct | 4*crossArea/perimeter | m_flow/ρ/crossArea |
| Wide Duct | distance between narrow, parallel walls | m_flow/ρ/crossArea |
| Packed Bed | diameterOfSpericalParticles/(1-fluidFractionOfTotalVolume) | m_flow/ρ/crossArea (without particles) |
| Device with rotating agitator | diameterOfRotor | RotationalSpeed*diameterOfRotor |
Syntax
Re = ReynoldsNumber(v, rho, mu, D)
Inputs (4)
| v |
Type: Velocity (m/s) Description: Mean velocity of fluid flow |
|---|---|
| rho |
Type: Density (kg/m³) Description: Fluid density |
| mu |
Type: DynamicViscosity (Pa⋅s) Description: Dynamic (absolute) viscosity |
| D |
Type: Length (m) Description: Characteristic dimension (hydraulic diameter of pipes) |
Outputs (1)
| Re |
Type: ReynoldsNumber Description: Reynolds number |
|---|