NE ENGINE

2009-04-09T02:41:00.000-07:00

A turbine is a rotary engine that extracts energy from a fluid flow. Claude Burdin (1788-1873) coined the term from the Latin turbo, or vortex, during an 1828 engineering competition. Benoit Fourneyron (1802-1867), a student of Claude Burdin, built the first practical water turbine. The simplest turbines have one moving part, a rotor assembly, which is a shaft with blades attached. Moving fluid acts on the blades, or the blades react to the flow, so that they rotate and impart energy to the rotor. Early turbine examples are windmills and water wheels.

Gas, steam, and water turbines usually have a casing around the blades that contains and controls the working fluid. Credit for invention of the modern steam turbine is given to British Engineer Sir Charles Parsons (1854 - 1931).

2008-06-09T13:36:00.000-07:00

2008-06-09T13:10:00.001-07:00

A rocket or rocket vehicle is a missile, aircraft or other vehicle which obtains thrust by the reaction of the rocket to the ejection of fast moving fluid from a rocket engine. Chemical rockets work by the action of hot gas produced by the combustion of the propellant against the inside of combustion chambers and expansion nozzles. This generates forces that accelerate the gas to extremely high speed and exerts a large thrust on the rocket (since every action has an equal and opposite reaction).

The history of rockets goes back to at least the 13th century.[1] By the 20th century, they have enabled human spaceflight to the Moon. In the 21st century, they have made commercial space tourism possible.

Rockets are used for fireworks and weaponry, as launch vehicles for artificial satellites, human spaceflight and exploration of other planets. While inefficient for low speed use, they are, compared to other propulsion systems, very lightweight and powerful, capable of attaining extremely high speeds with reasonable efficiency.

Chemical rockets store a large amount of energy in an easily-released form, and can be very dangerous. However, careful design, testing, construction, and use minimizes the risks.

2008-05-04T12:42:00.000-07:00

Turbojets are the oldest kind of general purpose jet engines. Two engineers, Frank Whittle in the United Kingdiom and Hans von Ohain in Germany, developed the concept independently during the late 1930s, although credit for the first turbojet is given to Whittle. Turbojets consist of an

air inlet, an air compressor, a combustion chamber, a gas turbine (that drives the air compressor) and a nozzle. The air is compressed into the chamber, heated and expanded by the fuel combustion and then allowed to expand out through the turbine into the nozzle where it is accelerated to high speed to provide propulsion. Turbojets are quite inefficient (if flown below about Mach 2) and very noisy. Most modern aircraft use Turbofans instead for economic reasons. Turbojets are still very common in medium range Cruise missiles, due to their high speed, low frontal area and relative simplicity.

2008-05-04T12:34:00.000-07:00

Jet engines provide thrust by taking in air, burning it with fuel, and accelerating the exhaust rearwards so that it ejects at high speed. The reaction against this acceleration provides the engine thrust. A Jet-engined Airbus A330-200of Egyptair lands Jet engines can provide

 Jet engines provide thrust by taking in air, burning it with fuel, and accelerating the exhaust rearwards so that it ejects at high speed. The reaction against this acceleration provides the engine thrust. A Jet-engined Airbus A330-200of Egyptair lands Jet engines can provide

2008-04-30T15:49:00.001-07:00

The internal combustion engine is an engine in which the combustion of fuel and an oxidizer (typically air) occurs in a confined space called a combustion chamber.
This Exothermic reaction creates gases at high Temperatureand Pressure, which are permitted to expand.

The defining feature of an internal combustion engine is that useful work is performed by the expanding hot gases acting directly to cause movement of solid parts of the engine, by acting on pistons, rotors, or even by pressing on and moving the entire engine itself.This contrasts with External combustion engines, such as Steam enginesand Stirling engines, which use an external combustion chamber to heat a separate working fluid, which then in turn does work, for example by moving a piston or a turbine.
The term Internal Combustion Engine (ICE) is almost always used to refer specifically to reciprocating piston engines, Stirling engines and similar designs in which combustion is intermittent. However, continuous combustion engines, such as jet engines, most rockets and many gas turbines are also internal combustion engines.

2008-04-23T02:18:00.000-07:00

Aerospace engineering is the branch of engineering that concerns the design, construction and science behind aircraft and spacecraft. Aerospace engineering has broken into

two major branches, aeronautical engineering and aeronautical engineering. The former deals with craft that stay within Eart’h atmosphere, and the latter deals with craft that operate outside of Earth’s atmosphere. While “aeronautical” was the original term, the broader “aerospace” has superseded the it in usage, as flight technology advanced to include craft operating in outer space.Aerospace engineering is often informally called rocket science in common terms.

2008-04-23T02:16:00.001-07:00

The aircraft is powered by two CFM International CFM56-7 turbofan engines in wing-mounted engine pods. CFM is a joint venture of General Electric Co. of the US and Snecma of France.

The aircraft carries 26,025l of fuel.
"In July 2005,Boeing launched the 737-900ER which will carry up to 215 passengers."
The aircraft's auxiliary power unit is the Honeywell 131-9B which provides 90kVA and air start capability.
The noise on the ground was reduced by up to 12dB by the installation of a new diffuser duct and silencer on the cooling vent on the auxiliary power unit। New quiet operating fans have been installed on the environmental control system and on the electronics cooling systems.

2008-04-23T02:13:00.000-07:00

The Boeing 737 twin engine airliner is the bestselling jetliner of all time. The 5,000th 737 was delivered in February 2006 and the aircraft has carried the equivalent of the world's population,

about seven billion passengers.
Over 3,000 aircraft of the first generation of 737s, which first flew in 1967, were built until the production run was completed in the year 2000.
"The Boeing 737 is the bestselling jetliner of all time."
The aircraft has allowed airlines to provide domestic routes and short-range international flights for more than 30 years. The design of the next-generation family of 737s began in 1991 and the newest 737s provide transcontinental and medium-range international flights.
Over 3,300 of the new generation aircraft have been ordered and the 2,000th was delivered in July 2006.

2008-04-23T02:10:00.001-07:00

Jet engines can be run on almost any fuel. Hydrogen is a highly desirable fuel, as, although the energy per mole is not unusually high, the molecule is very much lighter than other molecules.

It turns out that the energy per kg of hydrogen is twice that of more common fuels and this gives twice the specific impulse. In addition jet engines running on hydrogen are quite easy to build- the first ever turbojet was run on hydrogen.
However, in almost every other way, hydrogen is problematic. The downside of hydrogen is its density, in gaseous form the tanks are impractical for flight, but even in liquid form it has a density one fourteenth that of water. It is also deeply cryogenic and requires very significant insulation that precludes it being stored in wings. The overall vehicle ends up very large, and they would be difficult for most airports to accommodate. Finally, pure hydrogen is not found in nature, and must be manufactured either via steam reforming or expensive electrolysis. Both are relatively inefficient processes.

2008-04-23T02:04:00.001-07:00

Engines must be:
• lightweight, as a heavy engine increases the empty weight of the aircraft & reduces its payload.

• small and easily streamlined; large engines with substantial surface area, when installed, create too much drag, wasting fuel and reducing power output.
• powerful, to overcome the weight and drag of the aircraft.
• reliable, as losing power in an airplane is a substantially greater problem than an automobile engine seizing. Aircraft engines operate at temperature, pressure, and speed extremes, and therefore need to operate reliably and safely under all these conditions.
• repairable, to keep the cost of replacement down. Minor repairs are relatively inexpensive.

2008-04-23T02:01:00.001-07:00

This type of engine has cylinders lined up in one row. It typically has an even number of cylinders, but there are instances of three- and five- cylinder engines. An in-line engine may be either air cooled or liquid cooled. If the engine crankshaft is located above the cylinders,

it is called an inverted engine. Advantages of mounting the crankshaft this way include shorter landing gear and better pilot visibility. An in-line engine has a higher weight-to-horsepower ratio than other aircraft engines. A disadvantage of this type of engine is that the larger it is, the harder it is to cool. Due to this, airplanes that use an inline engine use a low- to medium-horsepower engine, and are typically used by light aircraft.

2008-04-23T01:59:00.003-07:00

An opposed-type engine has two banks of cylinders opposite each other. The crankshaft is located in the center and is being driven from both sides. The engine is either air cooled or liquid cooled, but

air cooled versions are used mostly in aviation. It can be mounted either vertically or horizontally. The advantage of a horizontally-opposed engine is that it allows better visibility and eliminates fluid lock typically found on bottom cylinders. An opposed engine also has a relative advantage in being mostly free of vibration. This is due to the fact that the pistons are located left and right of the crankshaft and act as balance weights for each other.

V-Type Engine

2008-04-23T01:59:00.001-07:00

Cylinders in this engine are arranged in two in-line banks, tilted 30-60 degrees apart from each other. The engine can be either air cooled or liquid cooled.

Radial Engine

2008-04-23T01:56:00.000-07:00

This type of engine has a row of cylinders arranged in a circle around a crankcase located in the middle. The combination of cylinders must be an odd number in each row and may contain more than one row. The odd number of cylinders allows for every other cylinder to be on a power stroke, allowing for smooth operation. The power output is anywhere from 100 to 3,800 HP.