Torque calculation
Posted inMarine Vehicles Performance

Torque calculation

4
For boats fitted with a rudder, the torque of the rudder or rudders is calculated as per the following formula and corrections.
 
It must be known that the torque necessary to manoeuvre a boat depends on:·         the speed of the water flowing on the surface of the rudder at a certain angle,·         the rudder size,·         the total sweep of the rudder (and part of the boat), if the rudder shaft is not perpendicular,·         the compensating surface of the rudder (balance).
 
C = S x [ (0.4 Lg) – Lc ] x V² x K C= Torque in kgmS= Total surface of rudder (H x Lg) in sq. mH= Height of rudder in mLg= Width of rudder in mLc= Compensation width in mV= Maximum speed of the boat in knots K= Coefficient in function of total rudder angle Port to starboard 70°K = 15.89Port to starboard 80°K = 17.80Port to starboard 90°K = 19.52   Corrections in function of the type of boat: For a boat with a steering nozzle C x 2.0For twin engine power boats with 1 rudderC x 0.5For boats fitted with several rudders (catamarans, monohulls)Multiply the calculated torque result by the number of rudders fitted on the boat.

4 Comments

No comments yet. Why don’t you start the discussion?

Comments are closed