PPLANT 2 - QUIZ 1 Reviewer

Pre-WWII Efforts

Pre-WWII Efforts

Before WWII, efforts to design a gas turbine engine were underway.

Post-WWII Progress

The war effort advanced gas turbine technology, enabling its use in commercial aircraft design.

Advantages Over Reciprocating Engines

Increased reliability
Longer mean times between overhaul
Higher airspeeds
Ease of operation at high altitudes
High power-to-engine weight ratio

150 BC

Egyptian philosopher and mathematician Hero invented the Aeolipile, a toy powered by a reaction effect of steam, demonstrating the Third Law of Motion.

1232

Chinese began using rockets as weapons, utilizing gunpowder to create reaction propulsion.

1500

Leonardo da Vinci drew the "chimney jack," rotated by hot gases flowing up a chimney.

1629

Giovanni Branca developed a stamping mill powered by jets of steam.

1678

Ferdinand Verbiest built a steam jet-powered model carriage.

1687

Sir Isaac Newton announced the three laws of motion, the basis of modern propulsion theory

1791

John Barber received the first patent for a basic turbine engine designed to propel a "horseless carriage," featuring a reciprocating type of compressor, combustion chamber, and turbine.

1872

Dr. F. Stolze designed the first true gas turbine engine with a multistage turbine and flow compressor (never self-powered).

1897

Sir Charles Parsons patented a steam turbine for ship propulsion.

1914

Charles Curtis filed the first application for a gas turbine engine.

1918

General Electric started a gas turbine division, where Dr. Stanford A. Moss developed the GE turbosupercharger, using exhaust gases to drive a centrifugal compressor for supercharging during W.W.I.

1920

Dr. A. A. Griffith developed a turbine design theory based on gas flow past airfoils.

1930

Sir Frank Whittle patented a gas turbine for jet propulsion. In April 1937, the first successful engine ran based on Whittle's designs and contributions from earlier pioneers.

Specifications of the First Jet Engine

Airflow: 25 lb/sec
Fuel Consumption: 200 gal/hr or 1300 lb/hr
Thrust: 1000 lb

Reciprocating Engine

A propeller accelerates a large volume of air by a small amount

Jet Engine

accelerates a small volume of air by a large amount.

Heat Engine

Convert heat energy into mechanical energy.

Types of Combustion Engines (Heat Engines)

1. External Combustion Engine
2. Internal Combustion Engine

Types of Internal Combustion Engines

1. Reciprocating Engines (RE)
2. Jet Engines

Reaction Engines

Generate thrust through a reaction to airflow in the opposite direction of a mass of air.

Ramjet

Air is compressed by the aircraft's forward motion; fuel burns in a duct.

Pulsejet

A ramjet variation where air enters through movable vanes and mixes with fuel in the combustion chamber. Explosions force the vanes shut, creating pulsating thrust.

Rocket

Carries both fuel and oxidizer. Expels hot gases through a nozzle to produce thrust.

Gas Turbine Engine

Internal combustion engine. A turbine is turned by hot compressed air and combustion gases.

Methods to Increase Jet Engine Thrust

1. Increase exhaust gas speed.
2. Increase exhaust gas quantity.

Relevant Principles (Bernoulli's Principle)

Pressure is inversely proportional to velocity.

Relevant Principles (Boyle's Law)

Pressure and volume are inversely proportional at constant temperature.

Brayton Cycle

- Thermodynamic cycle
- Two constant-pressure (isobaric) processes.
- Two reversible adiabatic (isentropic) processes.
- Used in gas turbine engines where compression and expansion occur in rotating machinery.

Gas Turbine Engine

intake, compression, combustion, and exhaust occur in separate sections simultaneously.

1. Gas Turbine Engine Components

An air inlet
2. Compressor section
3. Combustion section
4. Turbine section
5. Exhaust section
6. Accessory section
7. The systems necessary for starting, lubrication, fuel supply, and auxiliary purposes, such as anti-icing, cooling, and pressurization.

Turbojet Engine

The term "turbojet" referred to any gas turbine engine used in aircraft.

Turboprop Engine

- A gas turbine engine that drives a propeller through a speed reduction gearbox.
- Most efficient for speeds of 300-400 mph and short runway operations.

Turboshaft Engine

- Provides power through a shaft to operate non-propeller systems (e.g., helicopter rotors).

Turbofan Engine

The fan can be a part of the first-stage compressor blades or can be mounted as a separate set of fan blades.
Advantages
- Additional thrust without increasing fuel flow (fuel economy).
- Increased range and operating efficiency.
- Most widely used gas turbine engine for air transport due to its balance between turboprop efficiency and turbojet speed and altitude performance