Air Intake System Flashcards
(19 cards)
What are the three elements necessary to produce combustion in an internal combustion engine?
- Air
- Fuel
- Generation of Heat
These elements are fundamental for combustion to occur in an IC engine.
What is the purpose of the air intake system in an internal combustion engine?
To draw air into the engine for combustion.
A good combustion requires approximately 12,500 gallons of air.
What are the three main components of an intake system?
- Air Cleaner
- Throttle Body
- Intake Manifold
These components work together to facilitate air intake into the engine.
What is the function of an air cleaner in the air intake system?
To remove dust and other particles from the air while introducing atmospheric air into the engine.
The air cleaner element needs regular cleaning.
What are the types of air cleaner elements?
- Paper Type
- Fabric Type
- Oil Bath Type
Each type has its own method of filtering air.
What is a pre-air cleaner?
It uses centrifugal force to separate dust from the air.
Dust is sent to a dust trap, while clean air is directed to another air cleaner.
What does an intake manifold do?
Supplies air to each cylinder of the engine.
It consists of several pipes that distribute air.
What is a naturally aspirated engine?
An internal combustion engine that relies solely on atmospheric pressure for air intake.
These engines do not use turbochargers or superchargers.
What is forced induction in an engine?
Increasing the pressure of air entering the engine by compressing it.
This allows more fuel to be burned, increasing power.
What are the two primary methods of forced induction?
- Supercharging
- Turbocharging
These methods enhance engine performance.
What is volumetric efficiency (ηv)?
A measure of the effectiveness of an engine’s induction process.
It is calculated as the volume flow rate of air into the intake system divided by the volume displaced by the piston.
What is the typical volumetric efficiency for naturally aspirated SI and CI engines?
- SI engines: 80-85%
- CI engines: 85-90%
Turbocharged engines can exceed 100% volumetric efficiency.
What is a supercharger?
A device for pressurizing the air charge of an internal combustion engine.
It is driven by a pulley connected to the engine’s crankshaft.
What are the effects of supercharging an engine?
- Higher power output
- Greater induction of charge
- Better atomization of fuel
- Better mixing of fuel and air
- Quick acceleration of vehicle
- More complete and smoother combustion
These effects enhance engine performance.
What are the types of superchargers?
- Roots
- Twin-screw
- Centrifugal
- Vane type
Each type has unique operational characteristics.
How does a Roots supercharger function?
It has rotors that spin inside a housing, compressing air as they rotate.
The rotors are geared together and driven by a belt or chain from the engine crankshaft.
What are the phases of operation in a screw supercharger?
- Inlet phase
- Compression phase
- Discharge phase
Each phase plays a critical role in air compression.
What is the role of the impeller in a centrifugal supercharger?
To suck air into the center and push it to the outside of the rapidly spinning impeller blade.
This process increases the air pressure before discharging it.
What is the function of a diffuser in a centrifugal supercharger?
To utilize kinetic energy of fluid to decrease speed and increase pressure.
It gradually increases the cross-sectional area of the flow channel.
