Automobile

Except in a very small munber of experimental vehicles, automotive flywheels do not store energy.

Yes, but within the engine itself since the torque delivered by the piston -connecting rod - crankshaft is variable the flywheel inertia is used to transfer energy from the active part of cycle to the period when energy is needed for compression. This allows reduces the rpm fluctuations.

Yes, the flywheel does smooth the firing pulses out, and in that regard, it does store energy briefly. However, flywheels are not absolutely necessary for the operation of the engine.

My impression was that the OP was suggesting that the flywheel store energy independently of the engine.

Vehicles with automatic transmissions don't have 'flywheels', just a starter ring mounted on a big heavy torque converter that functions as a flywheel to smooth out the action.

Flywheels also serve as clutch pressure plates on standard transmission vehicles, and hold the starter ring.

Aircraft will rely on the propeller to act as the flywheel, to save weight.

Some hot rod motorcycle guys will remove the flywheel, to improve acceleration. Seems silly to me, but I have seen it done.

Dear YUVar..... as others here have mentioned the flywheel on most applications today is for cranking the unit over. Also note;... a quick search of wiki about Wankel engines turns up a wealth of information....In 1961, the Soviet research organization of NATI, NAMI and VNIImotoprom started experimental development, and created experimental engines with different technologies.[9] Soviet automobile manufacturer AvtoVAZ also experimented with the use of Wankel engines in cars but without the benefit of a license.[10] In 1974 they created a special engine design bureau, which in 1978 designed an engine designated as VAZ-311. In 1980, the company started delivering Wankel-powered VAZ-2106s (VAZ-411 engine with two-rotors) and Ladas, mostly to security services, of which about 200 were made.[11][12] The next models were the VAZ-4132 and VAZ-415. Aviadvigatel, the Soviet aircraft engine design bureau, is known to have produced Wankel engines with electronic injection for aircraft and helicopters, though little specific information has surfaced. Regards, Ray