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Re: [PSUBS-MAILIST] lift vs weight
I will start basic. Lift (boyantcy) is determined by the volume (displacement) of your sub's hull and the weight of you and all the added accesories. Accessories (ie. batteries, scuba tanks..) inside the sub, do not displace water so are added as their actual weights. The hull itself and accesories outside the sub (ie. manipulators, exostructure) weigh as much as they do in the air, minus the weight of the water volume they displace.
Fresh water weighs about 62.4 pounds per cubic foot, while salt water weighs about 64 pounds per cubic foot, and steel weighs about 485 lbs per cubic foot (density X volume) Subs are the sumation of several shapes, like cylinders, heads and spheres. The volume of cylinders and spheres are easy to look up, 2:1 elliptical heads require some integration but their weights can be looked up.
So it comes down to calculating the weight (or weighing everything) of everything out of the water and then calculating the volume of water that is displaced by everything (besides things that are already inside something, like occupants)
Regards,
Adam Lawrence
On 9/5/06, skrewgun007@aim.com <skrewgun007@aim.com> wrote:
so whats a good formula a layman can use for lift vs weight. I can figure my air mass in the sub ok but how do I include myself and how much lift does air create in fresh water and the displacement of the water? also from the steel vs weight? help me someone.