project biomimetismo

Instituto Superior TécnicoMestrado Integrado em Engenharia Biológica

2 de Maio de 2014

Projecto de BiomimetismoMid-Term Presentation

BiomimetismoProf. Gabriel Monteiro e Prof. Miguel

Prazeres

Mafalda Marques N.º 67276

Biomimetismo

Índice

Identificação do Problema

Validação do Problema

Soluções Existentes

Solução Biomimética

Biomimetismo

Identificação do Problema

Energy Efficient Submarines

Biomimetismo

Validação do Problema

A submarine needs to expend a large amount of energy just to keep

moving. Being completely immersed in water, it has to contend with much

higher drag forces than a vehicle traveling through air or a ship moving

on the surface of the water.

Each submarine cost approximately $3 billion to build To operate: $77 million per year per submarine http://www.psr.org/chapters/washington/energy-and-peace/trident.html

Biomimetismo


HULL SHAPEThe key to efficient hull design is

streamlining. A body moving through water is subjected to two retarding forces: form drag and skin friction. The first of these is larger for a blunt body than a tapered one, while the second is larger for a thin body

than a fat one. Minimizing both is a delicate balancing act. The most energy-

efficient design turns out to be a teardrop-shaped hull, in which the length is about 7.7 times the width. It’s no coincidence

that this is the shape found in many fast-swimming fish and marine mammals

Biomimetismo


ENERGY GENERATIONFish spend much of their time feeding,

so their energy supply is constantly being replenished. A submarine, on

the other hand, requires a self-contained energy source that has to

last weeks or months at a time. Some submarines, like those of the U.S.

Navy, have on-board nuclear reactors that have no difficulty meeting the

vessel’s energy needs. Energy supply is more of a problem for non-nuclear

submarines, which traditionally rely on batteries that have to be recharged

using on-board diesel generators. The latest generation of non-nuclear

submarines uses fuel cell technology to provide a much higher level of

energy efficiency.

Biomimetismo


PROPULSION SYSTEMThe most energy-efficient way to

move a submarine through the water is using a large, single-screw propeller. Not all submarines use one, however, because it can generate a lot of noise -- and remaining stealthy and silent is

essential for many submarine operations. As a compromise, a quieter but less efficient ducted

propulsor is used on many modern submarines. The need for stealth also

means submarines are usually designed to operate at slow speeds -- sometimes little more than walking pace -- so as to minimize the noise

generated by the vessel’s machinery. The slow speed of a submarine also

helps to save energy.

Biomimetismo

Solução Biomimética

Elephant Seal

project biomimetismo

Documents