Formulas
Smooth-Bore Flow Formula
The smooth-bore flow formula estimates a solid-stream nozzle's flow from its tip diameter and nozzle pressure. Bigger tips and higher pressures both raise the flow — and the reaction force the crew must hold.
A smooth bore's flow is predictable because nothing inside it moves: the discharge follows from the opening size and the pressure behind it. That predictability makes smooth bores easy to plan for at the panel.
The same formula reveals the trade-off. Going up a tip size or up in pressure to gain flow also raises the nozzle reaction, so flow and handling are decided together, not separately.
Where this shows up
Calculator
Nozzle Flow & Reaction