Internal Combustion Engine Basics

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary function of an internal combustion engine?

To convert electrical energy into heat energy

To convert mechanical energy into thermal energy

To convert heat energy into mechanical energy (correct)

To convert kinetic energy into potential energy

Which component of the internal combustion engine serves to connect the piston and the crankshaft?

Exhaust valve

Crankshaft

Spark plug

Connecting rod (correct)

What is the primary function of a spark plug in an engine?

To control the timing of the piston movements

To compress the fuel and air mixture

To deliver electric current to ignite the fuel/air mixture (correct)

To exhaust burnt gases from the cylinder

During which phase of the operating cycle does the fuel/air mixture enter the cylinder?

Intake Signup and view all the answers

How many strokes are completed in a four-stroke cycle per crankshaft revolution?

Two strokes Signup and view all the answers

What is the role of the exhaust valve in an internal combustion engine?

To let the burned fuel/air mixture exit the cylinder Signup and view all the answers

During which stroke does the spark plug fire to ignite the fuel/air mixture?

Combustion stroke Signup and view all the answers

Which of the following is NOT a basic part of an internal combustion engine?

Gearbox Signup and view all the answers

What does a diesel engine do differently compared to a spark-ignition engine?

It compresses only the air for ignition Signup and view all the answers

What defines a reciprocating engine?

It relies on back-and-forth movement of pistons Signup and view all the answers

What is the primary characteristic of a rotary engine?

It converts pressure into rotating motion Signup and view all the answers

Which efficiency is NOT typically associated with piston engines?

Chemical efficiency Signup and view all the answers

What happens if the inlet valve is closed at bottom dead center (BDC)?

The cylinder will receive a charge less than its capacity Signup and view all the answers

What is the purpose of the piston in an internal combustion engine?

To transfer force from expanding gas to the crankshaft Signup and view all the answers

What is valve overlap in the context of engine timing?

When both valves are open at the same time Signup and view all the answers

Who is credited as the originator of the Otto Cycle used in four-stroke engines?

Nikolaus Otto Signup and view all the answers

Study Notes

Engine Basics

Internal combustion engines convert heat energy into mechanical energy.
Gasoline vapor is mixed with air, compressed in a cylinder, and ignited by an electric spark.

Piston Engine Fundamentals

Mechanical, thermal, and volumetric efficiencies are critical for performance.
Operating cycles include Rotary, Diesel, 2-stroke, and 4-stroke configurations.
Key terms: piston displacement and compression ratio impact engine power and efficiency.

Engine Requirements

Quality engines are lightweight, reliable, durable, flexible, well-balanced, and possess an optimal weight per horsepower.

Reciprocating Engine

Characterized by the back-and-forth movement of pistons within the engine.

Operating Principles

The operational sequence of an internal combustion engine involves intake, compression, power/combustion, and exhaust.

Basic Parts of an Internal Combustion Engine

Cylinder: Holds the air-fuel mixture for combustion.
Intake/Exhaust Valves: Control the flow of air-fuel mixture into and exhaust out of the cylinder.
Connecting Rod: Links the piston and crankshaft, transferring power.
Piston: Moves within the cylinder and transfers force from combustion to crankshaft.
Crankshaft: Converts the piston's reciprocating motion to rotational motion.
Spark Plug: Ignites the fuel-air mixture via electric current in the combustion chamber.

Operating Cycles

Four-Stroke Cycle

Requires two revolutions of the crankshaft (720°) for four strokes.
Events:
- Intake/Induction
- Compression
- Power/Combustion
- Exhaust

Two-Stroke Cycle

Completes in one crankshaft revolution, requiring one upstroke and one downstroke.

Diesel Cycle

Comprised solely of air compression to ignite injected diesel fuel, named after Rudolf Diesel.

Rotary Engine Cycle

Also called Wankel Engine; utilizes an eccentric rotary design to convert pressure into motion, invented by Felix Wankel.

Summary of Pressure and Volume Inside the Cylinder

Dynamics of pressure and volume change during four-stroke cycles influence engine performance significantly.

Four-Stroke Valve Timing

Top Dead Center (TDC): The highest position of the piston.
Bottom Dead Center (BDC): The lowest position of the piston.
Valve lead: Valve opens before the ideal time.
Valve lag: Valve stays open beyond the ideal time.
Valve overlap: Both the intake and exhaust valves are open simultaneously.
Inlet valve timing is crucial to optimize cylinder filling; early opening ensures a full charge.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on the fundamentals of internal combustion engines. This quiz covers key concepts such as the operating principles, efficiencies, and essential parts of piston engines. Brush up on your understanding of how these engines function and their requirements for optimal performance.