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Two Example Scenarios
Robert Haas edited this page Apr 21, 2020
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1 revision
- Given:
- Air volume flow dV/dt
- All necessary geometry (diameters, length, roughness(material)) of the pipe
- Fluid data
- Unknown: Pressure difference Delta p
- How the program works:
- The velocity w must be calculated from dV/dt by the user.
- Calculation of the Reynolds number Re
- If Re <= 2300 (flow is assumed to be laminar), Fanning friction factor will be used for calculating f, Darcy-Weidbach formula for Delta p (for Delta p Hagen-Poiseuille would be also possible, if its strong assumptions are fulfilled)
- If Re > 2300 (flow is assumed to be turbulent), Churchill friction factor will be used for calculating f, Darcy-Weisbach formula for Delta p (for f Colebrook friction factor would be also possible)
- Application: Pressure difference alongside a piece of a pipe shall be calculated from volume flow measurements from a sensor shall be calculated
- Given:
- Pressure difference Delta p
- All necessary geometry (diameters, length, roughness(material)) of the pipe
- Fluid data
- Unknown: Air volume flow dV/dt
- How the program works:
- The mean velocity is calculated from Delta p via a formula for the turbulent flow regime
- The Reynolds number is calculated from the mean velocity.
- If Re > 2300 (flow is assumed to be turbulent), the calculation returns this mean velocity
- Otherwise, the velocity is calculated from Delta p via a formula for the laminar flow regime
- If Re <= 2300 (flow is assumed to be laminar), the calculation returns this velocity
- Otherwise, the calculation returns 0