four-stroke internal-combustion engine
Học thuậtThân thiện
Definition
- Noun:
- A type of internal-combustion engine in which a single thermodynamic cycle of operation (intake, compression, power, exhaust) is completed in four distinct strokes (movements) of the piston within the cylinder.
Usage
- The term four-stroke internal-combustion engine is a technical noun phrase used to specify the mechanical cycle of a common engine design. It is often contrasted with a "two-stroke engine."
- It functions as the subject or object in a sentence describing machinery, automotive technology, or engineering principles.
Examples
- Noun:
- Most modern cars and motorcycles are powered by a four-stroke internal-combustion engine.
- The invention of the four-stroke internal-combustion engine by Nikolaus Otto was a major milestone in industrial history.
- Compared to a two-stroke, a four-stroke internal-combustion engine typically has better fuel efficiency and lower emissions.
Advanced Usage
- The term is frequently shortened in common technical and casual usage to "four-stroke engine" or simply "four-stroke," with "internal-combustion" being implied in context.
- Example: "This lawnmower has a four-stroke engine, so you need to use pure gasoline, not a gas-oil mix."
Variants and Related Words
- Four-stroke engine (n): The common abbreviated form.
- Four-stroke cycle (n): Refers specifically to the thermodynamic cycle (Otto cycle) itself rather than the entire engine assembly.
- Otto engine (n): A historical synonym named after its inventor, Nikolaus Otto.
- Two-stroke internal-combustion engine (n): The direct counterpart that completes its cycle in two piston strokes.
Synonyms
- Four-cycle engine (n): An alternative name emphasizing the four-part cycle.
- Otto-cycle engine (n): A synonym referencing the specific thermodynamic cycle used.
Antonyms
- Two-stroke internal-combustion engine (n): An engine completing its cycle in two piston strokes.
- Electric motor (n): A motor using electrical energy, not internal combustion.
- Steam engine (n): An external combustion engine.
Related Technical Terms / Components
- Intake stroke (n): The first stroke where the air-fuel mixture enters the cylinder.
- Compression stroke (n): The second stroke where the mixture is compressed.
- Power stroke (n): The third stroke where the ignited mixture expands, doing work.
- Exhaust stroke (n): The fourth stroke where spent gases are expelled.
- Piston (n): The component that moves within the cylinder to create the strokes.
- Crankshaft (n): The shaft turned by the piston's motion.
Noun
- an internal-combustion engine in which an explosive mixture is drawn into the cylinder on the first stroke and is compressed and ignited on the second stroke; work is done on the third stroke and the products of combustion are exhausted on the fourth stroke