5 Flywheel and governor (17412)
Applications of flywheel : Used in Internal combustion engines, press machines, mills, punching machines.
The function of a governor is to regulate the mean speed of an engine, when there are variations in the load e.g. when the load on an engine increases, its speed decreases, therefore it becomes necessary to increase the supply of working fluid. On the other hand, when the load on the engine decreases, its speed increases and thus less working fluid is required. The governor automatically controls the supply of working fluid to the engine with the varying load conditions and keeps the mean speed within certain limits.
A turning moment diagram for a four stroke cycle internal combustion engine, we know that in a four stroke cycle internal combustion engine, there is one working stroke after a crank has turned through two revolution i.e.7200 . Since the pressure inside the engine cylinder is less than the atmospheric pressure during suction stroke therefore a negative loop is formed. During the compression stroke, the work is done on gases, therefore a higher negative loop is obtained.
Difference between Flywheel and Governor :
a) Fluctuation of energy -- The difference of maximum and minimum kinetic energy of flywheel is known as Fluctuation of energy
b) Coefficient of fluctuation of energy -- - It is defined as the ratio of the maximum fluctuation of energy to the work done per cycle. It is denoted by ke = (E1 - E2)/work done per cycle
Define following terms Fluctuation of energy, co-efficient of fluctuation of energy, co-efficient of fluctuation speed, maximum fluctuation of energy
Fluctuations of energy: The variations of energy above and below the mean resisting torque line are called fluctuations of energy.
Coefficient of fluctuation of energy: It may be defined as the ratio of the maximum fluctuation of energy to the work done per cycle. Mathematically, Coefficient of fluctuation of energy, E = Maximum fluctuation of energy/Work done per cycle
Working of Flywheel with the help of Turning moment diagram:
A flywheel used in machines serves as a reservoir, which stores energy during the period when the supply of energy is more than the requirement, and releases it during the period when the requirement of energy is more than the supply.