engines

• • POWER PLANT
  • An airplane has an engine called a power plant.
  • The power plant usually includes both the engine and the propeller.
  • The primary function of the engine is to provide the power to turn the propeller.
  • The power plant converts the chemical energy into mechanical energy which
  • creates the forward motion or thrust.
• • Reciprocating Engines The name ‘reciprocating engine’ is derived from the back and forth or reciprocating movement of the pistons. ● It is this motion that produces the mechanical energy needed to accomplish work.
• • Reciprocating Engines
  • The name ‘reciprocating engine’ is derived from the back and forth or reciprocating movement of the pistons.
  • It is this motion that produces the mechanical energy needed to accomplish work.
• Intake Valve - Needed to let the fuel/ air into the cylinder.
• Exhaust Valve - Needed to let the exhaust gasses out
• Exhaust Valve - Needed to let the exhaust gasses out
• The Piston - Moving within the cylinder. It has rings which seal the gasses in the cylinder, preventing any loss of power around the sides of the piston.
• The Connecting Rod - Forms a link between the piston and the crankshaft.
• The Crankshaft - Absorbs the power or work from all the cylinders and transfers it to the propeller
• The Crank Case - The crank case is the part of the engine that holds the crankshaft and the connecting rods.
• The Spark Plugs - ignites burning the fuel and air mixture.
• The basic principle for reciprocating engines involves the conversion of chemical energy in the form of fuel into mechanical energy
• This occurs within the cylinder of the engine through a process known as the four stroke operating cycle
• The four strokes are intake, compression, combustion, and exhaust
• Top Dead Center or TDC - It is the position of the piston at the highest point in an engine cylinder.
• Bottom Dead Center or BDC - It is the position of the piston at the lowest point of an engine cylinder.
• • INTAKE STROKE
  • Begins as the intake valve opens and the fuel and air mixture are drawn/enter into the cylinder.
  • The piston is at the top dead center, moving downward as the piston reaches the bottom dead center BDC intake stroke ends.
  • Intake valve is open, exhaust valve is closed.
  • Fuel and air enters the cylinder via the intake valve and the piston is moving downwards the BDC Bottom Dead Center.
• • COMPRESSION STROKE
  • This stroke begins when the intake valve closes and the piston starts moving upwards to the top dead center while the piston is moving up, it compresses the fuel and air mixture.
  • This phase of the cycle is used to obtain a much greater power output from the fuel and air mixture, once it is ignited.
  • Once the piston reaches the top dead center this stroke ends.
  • Both intake and exhaust valves are closed.
  • Fuel in the air is compressed by the piston as it travels upward.
• • COMBUSTION STROKE or POWER STROKE
  • During this stroke, compressed fuel and air is ignited by the spark plug.
  • This causes a tremendous pressure increase in the cylinder and forces the piston downward away from the cylinder head creating the power that turns the crankshaft.
  • The revolving crankshaft then transfers this energy to the aircraft’s propeller.
  • Spark plug ignites burning the fuel and air mixture. ● This controlled explosion pushes the piston downward, which in turn rotates the crankshaft; therefore it also rotates the propeller
• • EXHAUST STROKE
  • This stroke starts when the exhaust valves open, the piston moves upward to purge the cylinder of burned gasses.
  • Once the exhaust valve closes, the intake valve opens and the piston moves down again, repeating this cycle.
  • Exhaust valve is open and intake valve is closed.
  • The piston moves upward expelling burned gases out of the cylinder.
• the movement of the piston upward and downward is transferred through the connecting rod which then transfers it to the crankshaft, the revolving crankshaft then transfers this energy to the propeller, providing thrust to the aircraf
• Jet Engines or Turbines - Sucks air in front and pushes air out the back (force: thrust). It moves the airplane through the sky.
• A typical jet or turbine engine is divided into two areas, cold and hot.
• The hot section is where combustion occurs by adding fuel to the airflow provided by the intake of the cold section
• The Cold section includes the inlet air duct, the compressor and the diffuser.
• • INLET
  • Brings a free stream of air into the engine.
  • This focuses on decelerating the incoming air
• • COMPRESSOR
  • It is used to increase the air pressure before it enters the combustor.
  • Some compressors consist of several rows of rotors and stators, which are a series of airfoils.
  • Rotors are the moving parts of the compressor while stators are the fixed part.
• • BURNER or COMBUSTION CHAMBER
  • It sits between the compressor and turbine.
  • The fuel is mixed with high pressure air and burned to create high temperature exhaust gas that turns the power turbine and produces thrust.
• • TURBINE
  • It is comparable to a compressor because it also consists of several rows of rotors and stators; the turbine converts thermal energy to kinetic energy by expanding through nozzles then into rotational mechanical energy in a spinning roto
• NOZZLE - The function of a nozzle is to convert the thermal energy from the exhaust gases into kinetic energy in order to obtain high exhaust velocity.
• • TURBOJET
  • The simplest and the first type of gas turbine engine.
  • It is a type of engine that generates its thrust by burning 100% of the air.
  • It is usually use for jet fighters.
• • TURBOPROP
  • Type of jet engine that provides more efficiency when flying at lower speeds.
  • This engine is used for some big cargo airplanes.
  • Since it flies at lower speeds it is best suited for landing and taking off at shorter runways
• • TURBO SHAFT
  • A variant of a jet engine that has been optimized to produce shaft power, to drive
  • machinery instead of producing thrust.
  • It is most commonly used in applications that require a small but powerful lightweight
  • engine inclusive of helicopters.
• • TURBOFAN
  • The most modern variation of the basic gas turbine.
  • Modern airlines use turbofan engines to propel their airplanes through the air.
  • This is due to their higher thrust and fuel efficiency
• • Air Transport Association of America (ATA)
  • ATA Chapter list
  • Numerical, technical classification of all systems and subsystems on an aircraft
  • Every number has designated aircraft part
  • Current Name: Airlines for America
• FORE - front part of an aircraft
• AFT - Back part of an aircraft
• AIRFRAME - All parts of an aircraft except the powerplant.
• • COCKPIT - Also called as Flight Deck
  • It is where the pilot commands the airplane
• CARGO HOLD - This is where the check-in baggage of passengers are stored