Calculate siphon flow using head, tubing, and losses. View discharge, velocity, regime, and transfer time. Download records, print summaries, and compare scenarios with ease.
The table below shows sample scenarios calculated with the same model.
| Head (m) | Diameter (mm) | Length (m) | Total K | Flow (L/min) | Velocity (m/s) | Regime |
|---|---|---|---|---|---|---|
| 1.80 | 12.70 | 4.00 | 2.50 | 13.305 | 1.7506 | Turbulent |
| 2.50 | 19.00 | 6.00 | 2.70 | 36.480 | 2.1444 | Turbulent |
| 3.20 | 25.00 | 8.00 | 3.30 | 67.075 | 2.2774 | Turbulent |
| 4.00 | 32.00 | 10.00 | 3.80 | 119.674 | 2.4800 | Turbulent |
This calculator estimates steady siphon discharge with available head, pipe friction, and minor losses.
Velocity equation: v = √(2gH / (1 + fL/D + ΣK))
Flow equation: Q = A × v
Area equation: A = πD² / 4
Reynolds number: Re = ρvD / μ
Laminar friction factor: f = 64 / Re
Turbulent friction factor: Swamee-Jain approximation is used iteratively.
The term 1 in the denominator represents velocity head. The loss term ΣK covers entrance, fittings, bends, and exit effects.
Because friction factor depends on Reynolds number, the calculator updates velocity and friction factor repeatedly until the solution stabilizes.
This model assumes a fully primed siphon and single-phase liquid flow. Air leaks, cavitation, vapor formation, and inlet starvation are not modeled here.
This page helps estimate siphon behavior quickly when you need discharge, velocity, or friction losses for planning, testing, or software-assisted engineering workflows.
It supports repeatable calculations and clean exports. That makes it useful for documentation, interface prototyping, estimation scripts, and scenario comparison tasks.
The advanced input set allows realistic loss handling instead of relying only on ideal Torricelli flow. That produces estimates closer to practical tubing systems.
Available head is the vertical difference between the source liquid surface and the outlet. Greater head usually increases velocity and flow if all other losses stay unchanged.
Diameter changes cross-sectional area and the friction term L/D. A small increase in diameter can noticeably raise flow while also reducing friction losses.
Friction factor depends on Reynolds number, and Reynolds number depends on velocity. Velocity also depends on friction factor, so the solution must be updated repeatedly.
Minor loss coefficients represent local losses from entrances, bends, valves, contractions, and exits. These losses can significantly reduce discharge in short systems.
Yes. Enter the proper density and dynamic viscosity values. The calculator then updates Reynolds number, friction factor, and predicted flow accordingly.
No. It estimates flow from head and hydraulic losses only. Real siphons can fail if vapor pressure limits, leaks, or poor priming conditions occur.
It scales effective head to reflect nonideal operation. You can use it as a practical correction when measured performance is lower than the theoretical estimate.
Actual systems may include air ingress, changing liquid levels, rougher surfaces, extra fittings, flexible hose deformation, or outlet restrictions not entered here.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.