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Understanding and calculating marine displacement is essential for the design and operation of ships. This tutorial delves into the formulas and calculations associated with marine displacement, focusing on length, breadth, draft, and block coefficient.
2 wrz 2019 · A rough estimate of horsepower for displacement type hulls is fairly simple: 1. Maximum "hull speed", in knots, is equal to about 1.3 X the square root of the waterline length of the hull in feet. For example, say you have a displacement hull with a waterline length of 25 feet, then the hull speed is 5 x 1.3 = 7 knots.
Those two topics are covered first. The manner to determine a boat hull maximum displacement by both tank testing and by mathematical means (aka Simpson’s Rule) is covered. An example mathematical calculation follows. Then the three steps in determining the capacities – 1. Establishing an upper limit for weight capacity - (from boat ...
13 wrz 2017 · The displacement of the boat is based on a certain hull volume or cubic measurement of space BELOW the waterline. For example, in salt water, each cubic foot of immersed underbody volume will support about 64 lbs. In fresh water, it's a little less at about 62.5 lbs. per cubic foot.
The prismatic coefficient is the ratio of actual underbody volume to the volume of a prism having a length equal to the DWL, and a section equal to the boat's maximum sectional area. The prismatic coefficient provides an indication of the distribution of displacement.
14 lis 2006 · The usual calculation for displacement is determined by the areas of underwater sections (normally divided into 10 equal sections along the waterline length.) These numbers are punched into a formula called Simpsons Rule (just google it) which has long been the method for displacement calculation.
A semicircle cross section is assumed where Draft= BWL / 2 and CSA = (pi * Draft^2) / 2. If "Use minimum wetted surface" is not checked then CSA must be entered manually and BWL is used only to calculate "Length-to-Beam ratio"; the shape of the cross section is up to you! LB is always derived and cannot be input.
