The four-stroke Otto cycle is made up of the following four internally reversible processes: 1–2, isentropic compression; 2–3, constant-volume heat addition; 3–4, isentropic expansion; and 4–1, constant-volume heat rejection .
What are the 5 events of the Otto cycle?
This five-event sequence of intake, compression, ignition, power, and exhaust , is a cycle which must take place in the order given if the engine is to operate at all, and it must be repeated over and over for the engine to continue operation.
What are the processes involved in Otto cycle?
The four-stroke Otto cycle is made up of the following four internally reversible processes: 1–2, isentropic compression; 2–3, constant-volume heat addition; 3–4, isentropic expansion; and 4–1, constant-volume heat rejection .
What are the major processes in the air standard Otto cycle?
The Otto cycle is an air-standard cycle which approximates the processes in petrol or diesel engines. It is based on constant volume heat addition (combustion) and heat rejection processes, and isentropic compression and expansion .
What are the 4 processes of the 4 stroke cycle called?
An internal-combustion engine goes through four strokes: intake, compression, combustion (power), and exhaust .
What is the ideal Otto cycle?
Otto cycle Thermodynamics. 1. an ideal thermodynamic combustion cycle, as follows: a compression at constant entropy ; a constant-volume heat transfer to the system; an expansion at constant entropy; and a constant-volume heat transfer from the system.
What is the use of Otto cycle?
The Otto Cycle, describes how heat engines turn gasoline into motion . Like other thermodynamic cycles, this cycle turns chemical energy into thermal energy and then into motion. The Otto cycle describes how internal combustion engines (that use gasoline) work, like automobiles and lawn mowers.
What is difference between Miller and Otto cycles?
In the traditional Otto cycle, the intake valves close at the bottom dead center (BDC), while in the Miller cycle, the intake valves closing (IVC) is advanced to ahead of the BDC making the expansion ratio larger than the compression ratio (CR) which reduces the compression work due to the advancement of intake valve ...
What is K in Otto cycle?
Thermal Efficiency Derivation
A typical value for an air/fuel mixture is k = 1.35 .
What is the difference between Otto cycle and diesel cycle?
Otto cycle is used for petrol or spark ignition engine while diesel cycle is used for diesel or compression ignition engine. The main difference between Otto cycle and Diesel cycle is that in Otto cycle heat addition takes place at constant volume and in diesel cycle heat addition takes places at constant pressure.
Which cycle is more efficient?
Explanation: Otto cycle is more efficient than Diesel cycle for a given compression ratio. 6. For constant maximum pressure and heat input, the air standard efficiency of the gas power cycle is in the order.
What is the formula for compression ratio of Otto cycle?
For example, let assume an Otto cycle with compression ratio of CR = 10 : 1 . The volume of the chamber is 500 cm3 = 500×10 – 6 m 3 (0.5l) prior to the compression stroke. For this engine all required volumes are known: V 1 = V 4 = V max = 500×10 – 6 m 3 (0.5l)
What is the efficiency of Diesel cycle?
A typical diesel automotive engine operates at around 30% to 35% of thermal efficiency . About 65-70% is rejected as waste heat without being converted into useful work, i.e. work delivered to wheels. In general, engines using the Diesel cycle are usually more efficient, than engines using the Otto cycle.
How many cylinders does a 4-stroke engine have?
A four-stroke cycle engine is an internal combustion engine that utilizes four distinct piston strokes (intake, compression, power, and exhaust) to complete one operating cycle. The piston make two complete passes in the cylinder to complete one operating cycle.
How does a four-stroke engine work?
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 is the difference between a 2-stroke engine and a 4-stroke engine?
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).
