It works on a similar principle on the otto cycle.
It consists of three lobes rotor, casing, spark plug, suction, and exhaust ports.
The rotor of the engine is driven eccentrically in the casing in such a way that there are three separate volume trapped between the rotor and casing.
The volume trapped in each lobe performs the function of suction, compression, ignition, combustion, expansion, and exhaust processes.
we get three power strokes in one revolution of the rotor
In the case of a four-stroke I.C. engine, we get one power stroke in two revolutions of the crankshaft,
the Wankel engine develops six times the power for the same capacity of cylinder compared to reciprocating I.C .engines.
When a tip of the rotor passes the intake port, a fresh mixture starts getting into the primary chamber. The chamber draws fresh air until the second apex reaches the intake port & closes it. At the instant, the fresh air-fuel mixture is sealed into the primary chamber & is being removed for combustion.
The chamber one(between corner 1 to corner 2) containing the fresh charge gets compressed
to the form of the engine by the time it reaches to sparking plug.
While this happens, a replacement mixture starts getting into the second chamber(between corner 2 to corner 3).
When the sparking plug ignites, the highly compressed mixture expands explosively. The pressure of expansion pushes the rotor within the forward direction. This happens until the primary corner passes through the exhaust port.
As the peak OR corner 1 passes the exhaust port, the recent high-pressure combustion gases are liberal to effuse of the port.
As the rotor continues to maneuver, the quantity of the chamber goes on decreasing forcing the remaining gases out of port. By the time the corner 2 closes the exhaust port, corner 1 passes by the intake port repeating the cycle.
While the primary chamber is discharging gases, the second chamber(between corner 2 to corner 3) is under compression. Simultaneously, chamber 3(between corner 3 to corner 1) is drawing a fresh mixture.
This is the sweetness of the engine – the four sequences of the four-stroke cycle, which occur consecutively during a piston engine, occur simultaneously within the Wankel engine, producing power during a continuous stream.