The combustion stroke is
the third phase
, where the ignited air/fuel mixture expands and pushes the piston downwards. The force created by this expansion is what creates an engine’s power.
What is expansion stroke?
The
stroke in the operating cycle of a reciprocating engine in
which both the inlet and exhaust valves are closed, the fuel-air mixture has been ignited and burned, and the piston is being forced downward by expanding gases. This is the only stroke in which power is produced.
In which stroke does fuel combustion takes place?
1.
Intake stroke
: the intake stroke draws air and fuel into the combustion chamber. The piston descends in the cylinder bore to evacuate the combustion chamber.
What is premixed combustion phase?
The term premixed combustion in predominantly rate-controlled diesel combustion refers to the
rapid premixed combustion of a portion of the fuel injected during the ignition delay period
. This period is indicated as b→c in Figure 2.
What are the 4 phases of the 4 stroke cycle in the correct order?
An internal-combustion engine goes through four strokes:
intake, compression, combustion (power), and exhaust
.
What happens during the expansion stroke?
Combustion/Power/Expansion stroke
The combustion stroke is the third phase, where
the ignited air/fuel mixture expands and pushes the piston downwards
. The force created by this expansion is what creates an engine’s power.
What is the exhaust stroke occurs?
The exhaust stroke is the final stroke and occurs
when the exhaust valve is open and the intake valve is closed
. Piston movement evacuates exhaust gases to the atmosphere. As the piston reaches BDC during the power stroke combustion is complete and the cylinder is filled with exhaust gases.
Why thermal efficiency of 4 stroke engine is more than 2 stroke engine?
| 2 Stroke 4 Stroke | More power generation. Less power generation. | Produces more heat so it requires greater cooling and lubrication. Generates less heat. | Lower thermal efficiency Higher thermal efficiency |
|---|
What is difference between 2 stroke and 4 stroke?
In a 2-stroke engine, all five functions of the cycle are completed in only two strokes of the piston (or one revolution of the crankshaft). In a 4-stroke engine, the five functions require four
strokes
of the piston (or two revolutions of the crankshaft).
What is the working principle of 4 stroke engine?
What Are the Strokes of a 4-Cycle Engine? At the end of the compression (previous) stroke,
the spark plug fires and ignites the compressed air/fuel mixture
. This ignition/explosion forces the piston back down the cylinder bore and rotates the crankshaft, propelling the vehicle forward.
What are the four stages of combustion?
The cycle includes four distinct processes:
intake, compression, combustion and power stroke
, and exhaust.
What is combustion duration?
The combustion duration is defined as
the period from 10% to 90% of mixture combust up
, which is mainly a turbulent combustion and greatly be accelerated by turbulence in cylinder. As a result, the combustion duration will be kept almost constant in terms of crank angle; 3.
What is scavenging air?
Scavenging is
the process of replacing the exhaust gas in a cylinder of an internal combustion engine with the fresh air/fuel mixture
(or fresh air, in the case of direct-injection engines) for the next cycle. … Scavenging is equally important for both two-stroke and four-stroke engines.
What is the correct sequence of strokes in four-stroke cycle engines?
Explanation: This is the functioning of a four-stroke internal combustion engine. Explanation: The correct sequence is
intake->compression->expansion->exhaust
and expansion stroke is also called power stroke.
Why is a 4 stroke engine more efficient?
4-Stroke Engines
4 stroke engines have a cycle of intake, compression, power, exhaust, which is a more efficient process, resulting in
a reduction in amount of fuel used to power the engine
and fuel lost from the exhaust.
On what stroke is vacuum produced?
Manifold vacuum in cars. Most automobiles use
four-stroke Otto
cycle engines with multiple cylinders attached to a single inlet manifold. During the induction stroke, the piston descends in the cylinder and the intake valve is open.
