FieldengEngineering Fundamentals
Reynolds Number
Dimensionless Reynolds number from velocity, diameter, and dynamic or kinematic viscosity.
Dimensionless Reynolds number from velocity, diameter, and dynamic or kinematic viscosity.
App id: FUND-03. Reference version 1.1.
How to fill it
Fill the inputs. The tool shows the outputs.
On the tool screen, Calc is the working sheet. Presets stores values you reuse. Reference is the formula, assumptions, and provenance below.
Formula
Re = ρVD / μ = VD / νInputs
| Name | Unit |
|---|---|
| Velocity | m/s |
| Diameter | m |
| Density (optional) | kg/m3 |
| Dynamic viscosity (optional) | Pa-s |
| Kinematic viscosity (optional) | cSt |
Outputs
| Name | Unit |
|---|---|
| Reynolds number (hero result) | 1 |
Diagnose
Observations are context. They do not pass or fail a structure. See Diagnose.
Screening bands in the app: Laminar · Transitional · Turbulent.
| When | Observation | Severity |
|---|---|---|
Reynolds number < 2300 | Laminar | info |
Reynolds number ≤ 4000 | Transitional | caution |
Reynolds number > 4000 | Turbulent | info |
Assumptions
- Characteristic length is the stated diameter.
- Use density with dynamic viscosity, or kinematic viscosity alone. Dynamic viscosity wins when both are supplied.
- Laminar / transitional / turbulent bands are internal-pipe context, not a project criterion.
Provenance
- Re = ρVD / μ = VD / ν. Internal-flow regime bands are common textbook values.