Water Hammer Pressure Calculator (Joukowsky)
Surge pressure from sudden valve closure via the Joukowsky equation.
Stopping 2 m/s of water in a steel line adds ~24 bar. Joukowsky applies when closure is faster than 2L/a — slower closure scales the surge down.
Formula
Note: Instantaneous-closure upper bound. Real surge analysis must model the full pipeline (method of characteristics).
Water Hammer Pressure Calculator (Joukowsky) is a free water hammer for process, mechanical and water engineers — instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.
About Water Hammer Pressure Calculator (Joukowsky)
Surge pressure from sudden valve closure via the Joukowsky equation. The calculation implements ΔP = ρ·a·ΔV (Wylie & Streeter, Fluid Transients in Systems; AWWA M11 — steel pipe design). Stopping 2 m/s of water in a steel line adds ~24 bar. Joukowsky applies when closure is faster than 2L/a — slower closure scales the surge down.
How to use Water Hammer Pressure Calculator (Joukowsky)
- 1Enter Velocity change ΔV in m/s.
- 2Enter Wave speed a in m/s (Steel pipe ~1,200 · PVC ~400 · HDPE ~300 m/s).
- 3Enter Fluid density in kg/m³.
- 4Enter Operating pressure in kPa.
- 5Read Surge rise ΔP, Peak pressure instantly — no submit button needed.
- 6Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Water Hammer Pressure Calculator (Joukowsky)?
- ✓Implements the standard formula — ΔP = ρ·a·ΔV
- ✓Reference cited on-page: Wylie & Streeter, Fluid Transients in Systems; AWWA M11 — steel pipe design
- ✓One-click SI ⇄ Imperial toggle — values convert in place, physics stays in SI
- ✓Live worked example: the substitution recomputes from your numbers
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the Water Hammer Pressure Calculator (Joukowsky) use?+
It computes ΔP = ρ·a·ΔV, per Wylie & Streeter, Fluid Transients in Systems; AWWA M11 — steel pipe design. The formula is displayed under the result along with a worked example substituted with your own inputs.
What should I keep in mind when using this calculator?+
Stopping 2 m/s of water in a steel line adds ~24 bar. Joukowsky applies when closure is faster than 2L/a — slower closure scales the surge down. Note: Instantaneous-closure upper bound. Real surge analysis must model the full pipeline (method of characteristics).
Does this work for any fluid?+
Yes — density and viscosity are inputs (with common fluids suggested in the field hints), so the same physics applies to water, oils, gases and process fluids. Compute always runs in SI internally, so unit mix-ups can't corrupt the result.
Is the Water Hammer Pressure Calculator (Joukowsky) free to use?+
Yes — completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.
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