Fluid Mechanics
Water Hammer Simulator
Analyze fluid transient shockwaves caused by instant valve closures. Adjust density, acoustic velocity, and piping configurations to prevent cavitation and pressure surges.
Equation
Joukowsky
Transient Wave
Mesh
61 Nodes
Dynamic Profile
Output
CSV
Export Ready
Parameters
Fluid / Pipe Preset
Transient Wave cycle
Physics & Governing Equations
Joukowsky Equation
ΔP = ρ * c * ΔV
Pressure Head Rise
ΔH = ΔP / (ρ * g)
Wave Transit Time
T = L / c
Reflected Cycle Period
Period = 4T
Water hammer occurs when moving fluid is forced to stop suddenly (e.g., valve closure).
A high-pressure compression wave travels at 1200 m/s towards the reservoir, reflecting back and forth.
For safety, valve closure time should be greater than 2T to reduce the peak surge pressure.
Fluid Pressure propagation
Simulation Time: 0.000sPhase: Steady State Flow
Surge Pressure
24.00bar
= 2400 kPa
Surge Head
244.6m
Water column equivalent
Transit Time (T)
0.250s
Time to reach reservoir
Wave Cycle Period
1.000s
Time for full 4T cycle
Pressure Surge Trends
Transient Results
| Time (s) | Surge Pressure (bar) | Equivalent Head (m) |
|---|---|---|
| 0.000 | 24.00 | 244.6 |
| 0.067 | 23.06 | 235.1 |
| 0.133 | 22.15 | 225.8 |
| 0.200 | 21.29 | 217.0 |
| 0.267 | 20.45 | 208.5 |
| 0.333 | 19.65 | 200.3 |
| 0.400 | 18.88 | 192.4 |
| 0.467 | 18.14 | 184.9 |
| 0.533 | -17.43 | -177.7 |
| 0.600 | -16.74 | -170.7 |
| 0.667 | -16.09 | -164.0 |
| 0.733 | -15.46 | -157.6 |
| 0.800 | -14.85 | -151.4 |
| 0.867 | -14.27 | -145.4 |
| 0.933 | -13.71 | -139.7 |
| 1.000 | 13.17 | 134.3 |
| 1.067 | 12.66 | 129.0 |
| 1.133 | 12.16 | 123.9 |
| 1.200 | 11.68 | 119.1 |
| 1.267 | 11.22 | 114.4 |
| 1.333 | 10.78 | 109.9 |
| 1.400 | 10.36 | 105.6 |
| 1.467 | 9.95 | 101.5 |
| 1.533 | -9.56 | -97.5 |
| 1.600 | -9.19 | -93.7 |
| 1.667 | -8.83 | -90.0 |
| 1.733 | -8.48 | -86.5 |
| 1.800 | -8.15 | -83.1 |
| 1.867 | -7.83 | -79.8 |
| 1.933 | -7.52 | -76.7 |
| 2.000 | 7.23 | 73.7 |