Hull Speed
Compute the hull speed of a displacement vessel, V ≈ 2.43·√(LWL), in knots, from the waterline length (LWL, in meters). It is the theoretical limit of a hull's economical speed: as the boat approaches it, it gets trapped in its own bow wave and the required power soars. That is why sailboats and displacement craft rarely exceed it. Enter the waterline length.
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Velocidade de casco (hull speed)
Todo barco de deslocamento (que empurra a água em vez de planar sobre ela) tem um teto natural de velocidade econômica: a velocidade de casco, V ≈ 2,43·√(LWL) em nós, função apenas do comprimento na linha d'água. A razão é elegante: ao acelerar, o casco cria uma onda de proa cujo comprimento cresce com a velocidade; quando essa onda iguala o comprimento do barco, ele fica 'preso' no vale da própria onda e teria de subir nela — a potência exigida dispara para ganhos mínimos de velocidade. Por isso veleiros e trawlers raramente ultrapassam esse limite, e cascos mais longos são intrinsecamente mais rápidos. Informe o comprimento na linha d'água.
Related Tools
Extrusion Haul-Off Speed
Calculate the haul-off speed of an extrudate by mass conservation, v = Q ÷ A, from the extruder volumetric flow Q (m³/s) and the final product cross-sectional area A (m²). After the die, the extrudate is pulled by a haul-off (belts, rollers, winder) at a speed that must be SYNCHRONIZED with the extruder flow: by mass conservation, in steady state, the volume leaving the extruder per second must equal the volume the haul-off removes per second (product area times line speed). If haul-off is too fast for the flow, the product thins below size or breaks; if too slow, material accumulates and deforms. This speed sets the line's PRODUCTIVITY (metres per minute) and, with die swell and draw-down ratio, sets the final dimensions. Controlling the extrusion-haul-off synchrony — often with dimension sensors and closed loop — is essential for dimensional uniformity of pipes, profiles, wire and sheet. This gives the theoretical line speed from flow and desired section. Enter the flow and the product section area.
Ship Speed Knots MPH Converter
Converts ship speed in knots to km h, miles per hour and meters per second showing equivalents in common nautical and metric units.
Hull Wetted Surface
Estimate the hull's wetted surface area by Denny's formula, S = 1.7·L·T + ∇/T, from the length (L), the draft (T) and the displaced volume (∇). The wetted surface drives frictional resistance — the largest share of drag at low speeds — and underlies power calculation and the area to be coated with antifouling paint. Enter the length, the draft and the displaced volume.
The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.