Round Bilge Hull Resistance Method Selector

Description

This Excel based app lets the user check which methodical series is most suitable for a round bilge hull form.

Purpose
“The most used form of marine vessels is the round bilge hull and a large percentage of these are high speed.
With a large variation of ship parameters like displacements, length, breadth and speed, it is important to know which is the right method to use to ascertain the resistance and other parameters.
This excel file takes the input of the ship’s parameters and tells the designer where the vessel lies in terms of the ranges of parameters for the different methods and depicts them as “”pass”” or “”fail””.
This also gives the percentage by which the value of the ship under investigation lies with respect to the range.
The user can carry out a number of what-if computations by changing the parameters of the vessel to attain suitability for a particular series.”

The following methodical series are used here for the suitability check
Series(No. of Models)
1 Nordstrom(12*)
2 De Groot(31*)
3 Marwood-Silverleaf (30*) )
4 Series 63 (5)
5 Series 64 (27)
6 SSPA (9)
7 NPL (22)

8 S-NPL extended(10)
9 YP (3)
10 SKLAD (27)
11 NRC (24)
12 D-Series (13)
13 VTT (4)
14 MARIN HSDHF(40)
15 AMECRC HSDHF (14)
14 MARIN HSDHF(40)

15 AMECRC HSDHF (14)

Instructions for use
Following values are taken as inputs
L LENGTH BETWEEN PERPENDICULARS (m)
B BREADTH MOULDED (m)
T DRAUGHT MOULDED (m)
Δ DISPLACEMENT (tonnes)
V SPEED (kn)

Following intermediate values are created

FnL LENGTH FROUDE NUMBER
Fn∇ VOLUME FROUDE NUMBER
L/B LENGTH TO BREADTH RATIO
B/T BREADTH TO DRAFT RATIO
CB BLOCK-CO-EFFICIENT

The “OUTPUT” sheet tells you for every series and every parameter whether it passes of fails and by which margin. The deviation is given by formulae as per the diagram alongside