Gearboxes and Jet Engines in Nature

GROUP 2 - BIO20/A1

MEMBERS:

-CARORO, REINA HOSANNAH T.

-PALERO JR., DANTE M.

-PORTES, RENZ OLIVER P.

-TANAMOR, ALAISA

-VENCER, KARL DANIEL C.

What are Gearboxes?•consists of gears that converts the rotational energy of the engine to a rotational speed appropriate for the wheels.

•allow you to change gears in the vehicle so that the motor is used most efficiently

•commonly used in vehicles, and turbines

How do Gears work?•Gears for Speed•Gears for Force

Natural Gearboxes

Jet Engines•an engine using jet propulsion for forward thrust, mainly used for aircraft.

•takes in air from one end and expels it from the other at a much greater speed.

Jet Engines - Hans von Ohain and Sir Frank Whittle•Dr. Hans von Ohain and Sir Frank Whittle are both recognized as being the co-inventors of the jet engine.

•Each worked separately and knew nothing of the other's work.

Parts of a Jet Engine

Jet Engines in Nature

100-Million-Year-Old Technology Under the Sea When a submarine fills its ballast tanks with water, the ship becomes heavier than water. Emptying the tank would resurface the submarine.

The nautilus employs the same technique. They produce a special gas transferring it to its chambers expelling water to regulate its buoyancy allowing it to surface or dive when being chased.

Submergence Submarines’ diving techniques resemble those of fish, which

are able to control their relative density in order to rise or dive in the water.

In their bodies, bony fish have a swim bladder that gives them their buoyancy. Through diffusion, they can change volume of air in the bladder, the fish’s density can be made equal to that of the surrounding water at a given depth.

Living Things and Flight technology

Living Things and Flight technology

Airfoil◦ a structure with curved surfaces designed◦ used as the basic form of the wings, fins, and horizontal stabilizer of most

aircraft.

How do birds fly?simplifies the dynamics of flightdepicting Newton’s second law of motion (action-reaction).In order for birds to fly, they must, in simplest sense, be aerofoils.

The characteristics birds have in mastering flight include:

Their flapping wings◦ Upon down stroke the bird brings thrust (forward force), and lift (upward force) upon up stroke.

The Bernoulli Effect◦ wherein faster airflow means lower air pressure and vice versa◦ The higher pressure on the underpart of the wing keeps the bird on air.

Aerodynamic body◦ streamlined body enables the birds to counteract drag (backward force) ◦ Drag --- produced in landing by flapping down the tail feathers.

Air-pocketed bones◦ Pneumatic bones and more simplified anatomy than their reptilian ancestors

considerably make birds lighter thus reducing their weight (downward force) and promoting lift.

Bird’s wing and Aircraft wings

How does a plane fly? Four forces of flight Lift

◦ an upward force that is created by the effect of the airflow ◦ one of the key aerodynamic forces.

Thrust◦ a forward force which pushes the airplane through the air◦ varies with the amount of engine power being used◦ The air is pulled in the engine and then thrown out in the opposite direction◦ Household fan --- an easy example

Drag◦ opposite force◦ helps in reducing the speed of an aircraft◦ caused due to differences in air pressure.

Weight◦ as lift helps in flying the aircraft in the air, the weight acts in an opposite manner.◦ pushes the plane downward due to the gravitation force

Mini wing reduces the vortex drag

Vortices◦ create a significant amount of drag on the aircraft◦ They create a turbulent and occasionally dangerous pressure wake

Aviation research studies have revealed that when vultures fly, they open their quill feathers—the large feathers at the edge of the wing—like the fingers of a hand.

Wing Loading

A measurement that relates the mass of an aircraft or bird to the total wing area. The relationship between wing area and body weight is given in kilograms per square meter (or grams per square centimeter).

To calculate wing loading, divide the mass of the bird or plane by the total area of the upper surface of its wings:wing loading = body mass (kg)/wing area (m2)

Falcons◦ the fastest animals on earth◦ can tuck their wings in to reduce drag.

B – 1B Swing-wing Bomber◦ bomber that has adjustable wings that can be

swept back for high speed◦ tight angle of the wings helps to reduce drag,

giving it supersonic speed capability.

Albatross◦ has the longest wingspan of any bird◦ The long, narrow, pointed wings coupled with

low loading enable the birds to glide effortlessly on up draughts – sometimes for months at a time.

Glider◦ Glider’s long, slim wings and low wing loading

maximizes lift --- enabling the gliding action.

Hummingbird◦ have the ability to hover in one place by

rotating their wings.

Helicopter◦ has the ability to rotate its wings, enabling

it to hover in one place.

Godwit◦ Migratory birds◦ have high aspect ratio wings equipped for

long rages and endurance at a relatively fast speed.

Airbus◦ Airplanes with high aspect ratio wings have

long ranges and endurance times at fast speeds.

King vulture◦ high aspect ratio wings --- allow to spend

hours in flight, soaring slowly without flapping their wings.

Spy Plane◦ high aspect ratio wings --- allow it to move

slowly, not using much energy

References: BIOMIMETICS: Technology Imitates Nature by Harun Yahya

http://inventors.about.com/library/inventors/bljetengine.htm

http://en.wikipedia.org/wiki/Jet_engine

http://www.explainthatstuff.com/gears.htm

http://www.wisegeek.org/what-is-a-gearbox.htm