免费伯努利压力计算器
使用伯努利方程计算流体的压力变化。
Pressure at Point 2
90,825.00 Pa
Pressure at Point 2 vs Pressure at Point 1
公式
## Bernoulli's Equation For steady, incompressible, inviscid flow along a streamline, the total energy per unit volume is conserved. ### Formula **P1 + 0.5 rho v1^2 + rho g h1 = P2 + 0.5 rho v2^2 + rho g h2** Solving for P2: **P2 = P1 + 0.5 rho (v1^2 - v2^2) + rho g (h1 - h2)** Faster flow means lower pressure (the Venturi effect).
计算示例
Water in a horizontal pipe narrows from 2 m/s to 5 m/s. P1 = 101325 Pa.
- 01P2 = P1 + 0.5 * 1000 * (4 - 25) + 0
- 02P2 = 101325 + 500 * (-21)
- 03P2 = 101325 - 10500
- 04P2 = 90 825 Pa
常见问题
Why does faster flow mean lower pressure?
Energy is conserved along a streamline. If kinetic energy (flow speed) increases, the pressure energy must decrease to compensate.
When does Bernoulli fail?
It fails for viscous flows (high friction), compressible flows (high Mach number), and unsteady flows. Real pipes always have some viscous loss.
Does Bernoulli explain how aeroplane wings work?
Partially. The pressure difference is real, but the common explanation that air travels faster over the curved top because of longer path length is incorrect. Circulation and angle of attack are the primary factors.
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