Pipe Flow

Pipe Flow - online utility on ToolBox.

📐 工作原理与说明

截面积 A = π·d²/4（d 以 m 计）；流量 Q = A × 流速 v（m³/s）= A·v × 1000（L/s）= A·v × 3600（m³/h）

Pipe Flow - online utility on ToolBox.: computes and outputs results from the input parameters.

管内径 (mm)

流速 (m/s)

管长 (m)

管材类型

水温 (°C)

请输入参数后点击计算

Item	Formula / Note	Source / Standard
Continuity equation	Q = v × A with A = πD²/4; Q in m³/s or L/s	Basic fluid mechanics
Manning formula	v = (1/n) × R^(2/3) × i^(1/2); n is roughness (PVC 0.010, cast iron 0.013)	Classic Chézy–Manning empirical formula
Hazen-Williams	v = 0.849 × C × R^0.63 × i^0.54, C = 130–150 (high value for plastics)	Common empirical formula in water supply engineering
Velocity limits	Service main 1.0–1.5 m/s, branch 0.8–1.2 m/s; keep ≤1.0 m/s for noise control	GB 50015-2019 Standard for Design of Building Water Supply and Drainage
Diameter estimate	D = √(4Q / (π × v)); choose economic velocity first, back-calculate and round up	Standard design manual procedure

📚 深度解析：水管流量估算

给水流量

DN20 管内径≈21mm，经济流速 1.0m/s 截面积=π×0.0105²≈3.46e-4㎡流量≈3.46e-4×1.0≈0.000346 m³/s≈1.25 m³/h

⚠️ 使用说明与注意事项