# Help Formula?

Discussion in 'Stability' started by Laranjo123, Jul 10, 2011.

1. ### Laranjo123Previous Member

Do you have a formula for VCG VCB LCG LCB and period of rolling?
Need pls thesis purposes.
It would be great if you have ebooks to share cause i've been researching those formulas but the net does'nt have them. (i think)

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### terhohalmeBEng Boat Technology

Any naval architecture study book will do the job. For thesis YOU need to find them!

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### MengWaltonJunior Member

I have all of those, cant remember them all off the top of my head, i can remember some, but ill double check in my book tomorrow, and post them, if someone hasnt already put the formule down.

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### Olavnaval architect

VCG = (∑mi * zi) / mtotal

VCB = (∫z * A *dz) / V

LCG = (∑mi * xi) / mtotal

LCB = (∫x * A * dx) / V

LCG = LCB for equilibrium

A = sectional area
mi = single mass
mtotal = total mass = ∑mi
V = displaced volume
x = coordinate in longitudinal direction
z = coordinate in vertical direction

Concerning roll period you might want to have a look at this thread and make up your own opinion.

Just out of curiosity: What subject do you study/write your thesis in? If it's anything along the lines of naval architecture I'd highly recommend to postpone your thesis and start it all over from the very beginning. These basics of hydrostatics are first year stuff.

5. ### Laranjo123Previous Member

sir pls do post them i need more formulas( if you find them?) . Im going to get their average values....

6. ### Laranjo123Previous Member

anyone who have formulas can post them here ^__^

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### commodoreNew Member

I don't want to be rude or offensive, but Olav already posted such formula:

8. ### Laranjo123Previous Member

thx guys i have the book it's called parametric design by michael g parsons. I only got the chapter 11 of it. haha

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### daiquiriEngineering and Design

haha

...

??

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