Solid stream length is computed per GB 50974: Sk = Hq/(1+φ·Hq), with φ set by nozzle size (13mm→0.0165, 16mm→0.0124, 19mm→0.0097, 22mm→0.0077); exit velocity follows v=√(2gHq).
根据喷嘴压力、有效系数与喷射角度,估算充实水柱长度、水平有效射程和喷嘴出口流速。
请输入参数后计算。
| Item | Formula / Note | Source / Standard |
|---|---|---|
| Effective water column | Sk = 10–13 m (effective reach) | GB 50974-2014 §7.4 |
| Nozzle pressure | Pq ∝ Sk² via nozzle coefficient | Freeman formula |
| Hydrant outlet pressure | Hxh = Hq + hose losses | GB 50974-2014 §7.4 |
| Nozzle tilt | 45° gives max horizontal reach | Projectile motion |
| Design flow | Q = 19–40 L/s per standpipe | GB 50974-2014 §7.1 |
| Definition | Reach to 90% water through 38cm ring | NFPA 14 §7.2 |