Sunday, November 27, 2011

Coeficientes de Formas

Ship's hull form coefficients

(At preliminary merchant ship design)


Introduction

HELLO!

Herein I present a form to get basic hull form coefficients of merchant ships, following the formulae and concepts explained in Refs. 1 and 2, in order to serve as a guidance in the preliminary stage of a ship's design.

The main goal of this form is to get reasonable values of block (CB), midship section (CM) and loadline (CW) coefficients to be used in the different modules presented in the program Arqnaval, enclosed to the book Ref.2, and the program Getxonaval, being under construcion, to be used on-line via any browser, both intended to offer approximate and quick calculation methods in the preliminary stage of a ship design.

Some additional coefficients are also calculated and displayed in the enclosed form, of a lesser interest but that can also be of some utility.


Saturday, November 5, 2011

Stability Calculation


Stability Calculation

(At preliminary stage of cargo ships design)


Introduction


Calculation of the stability is one of the basic and primary tasks that are to be done at the initial ship design stage, where it is not absolutely necessary to be quite exact, but where a quick calculation is very advisable, even if being approximate, allowing to analyze many alternative dimensionings in a short time. In this blog post I enclose a form where main cargo ship dimensions are to be input by the user and from them the program makes an approximate calculation and stability results are displayed for transverse metacentric height GM and righting levers GZ at several heeling angles.