免费管道流速计算器
根据流量和管径计算管道中的流速。
Average Velocity
1.91 m/s
Average Velocity vs Volumetric Flow Rate (Q)
公式
## Pipe Flow Velocity Velocity is derived from the continuity equation by dividing flow rate by cross-sectional area. ### Formula **V = Q / A = 4 Q / (pi D^2)** where Q is the volumetric flow rate and D is the pipe inner diameter. Maintaining velocities within recommended ranges (1-3 m/s for water) avoids excessive pressure loss and erosion.
计算示例
15 L/s flowing through a 100 mm diameter pipe.
- 01Q = 15 L/s = 0.015 m^3/s
- 02A = pi x 0.1^2 / 4 = 0.007854 m^2
- 03V = 0.015 / 0.007854 = 1.91 m/s
常见问题
What is a safe maximum velocity for water pipes?
For potable water systems, 1.5-2.5 m/s is typical. Fire protection systems may allow up to 3-4 m/s. Exceeding 3 m/s risks water hammer, noise, and accelerated pipe erosion.
Is this the velocity at the centre of the pipe?
No, this is the average (bulk) velocity. In turbulent flow, the centreline velocity is about 1.2 times the average. In laminar flow, the centreline velocity is exactly 2 times the average.
How does pipe size affect velocity?
For a given flow rate, halving the diameter quadruples the velocity (since area scales with D^2). This dramatically increases friction losses, which scale with V^2.
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