functionReynoldsNumber
Return Reynolds number from v, rho, mu, D
Extends from Modelica.Icons.Function (Icon for functions).
Information
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 |
Inputs
| Type | Name | Default | Description |
|---|---|---|---|
| SI.Velocity | v | Mean velocity of fluid flow | |
| SI.Density | rho | Fluid density | |
| SI.DynamicViscosity | mu | Dynamic (absolute) viscosity | |
| SI.Length | D | Characteristic dimension (hydraulic diameter of pipes) |
Outputs
| Type | Name | Default | Description |
|---|---|---|---|
| SI.ReynoldsNumber | Re | Reynolds number |