Flywheel

Flywheel

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  Flywheel
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  Flywheel  A rotatingmechanical device that is used to store rotational energy.  A flywheel is used in machines , serves as a reservoir which stores energy during the period where the supply of energy is more than the requirement.  Conversely, a flywheel releases stored energy by applying torque to a mechanical load, thereby decreasing the flywheel's rotational speed.
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  Flywheel during In otherwords it can be defined as “it stores energy power stroke and delivers during idle strokes”.  A little considerations will show that when the flywheel absorbs energy, its speed increases and when it releases, the speed decreases. Hence a flywheel does not maintain a constant speed, it simply reduces the fluctuation of speed.  The flywheel’s position is between the engine and clutch patch to the starter.
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  Flywheel position
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   A Flywheelis used to maintain constant angular velocity of the crankshaft in a reciprocating engine. In this case, the flywheel—which is mounted on the crankshaft— stores energy when torque is exerted on it by a firing piston and it releases energy to its mechanical loads when no piston is exerting torque on it.
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  Function of Flywheel 1.Flywheel absorbs energy, its speed increases and when it releases energy, the speed decreases. 2. Hence a flywheel does not maintain a constant speed, it simply reduces the fluctuation of speed. 3. In other words, a flywheel controls the speed variations caused by the fluctuation of the engine turning moment during each cycle of operation.
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  Application of Flywheel 1.Flywheel is used to maintain constant angular velocity of the crankshaft in reciprocating Engine. 2. Flywheel is used to provide continuous energy in systems where the energy source not continuous. 3. A flywheel is used to supply intermittent pulses of energy at transfer rate that exceed the ability of its energy source. 4. Flywheel is used in riveting machine to store energy from the motor. 5. Flywheel is used to orient satellite instrument without the use of thruster rocket.
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  Other Applications
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  Turning Moment Diagramfor single cylinder 4-Stroke I.C Engine:- A turning moment diagram for a four stroke cycle internal combustion engine is shown in Fig. We know that in a four stroke cycle internal combustion engine, there is one working stroke after the crank has turned through two revolutions, i.e. 720° (or 4 π radians). Since the pressure inside the engine cylinder is less than the atmospheric pressure during the suction stroke, therefore a negative loop is formed as shown in Fig.
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  Turning Moment Diagramfor single cylinder 4-Stroke I.C Engine:-  During the compression stroke, the work is done on the gases, therefore a higher negative loop is obtained.  During the expansion or working stroke, the fuel burns and the gases expand, therefore a large positive loop is obtained. In this stroke, the work is done by the gases.  During exhaust stroke, the work is done on the gases, therefore a negative loop is formed.  It may be noted that the effect of the inertia forces on the piston is taken into account in Fig.
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  Coefficient of fluctuationof energy::-
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  Coefficient of fluctuationof speed::- The difference between the maximum and minimum speeds during a cycle is called the maximum fluctuation of speed. The ratio of the maximum fluctuation of speed to the mean speed is called the coefficient of fluctuation of speed. Let N1 and N2 = Maximum and minimum speeds in r.p.m. during the cycle, and
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  Advance and ModernFlywheel  Flywheels have also been proposed as a power booster for electric vehicles. Speeds of 100,000 rpm have been used to achieve very high power densities.  Modern high energy flywheels use composite rotors made with carbon-fibre materials. The rotors have a very high strength-to- density ratio, and rotate at speeds up to 100,000 rpm. in a vacuum chamber to minimize aerodynamic losses.
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  Disadvantages  There aresafety concerns associated with flywheels due to their high speed rotor and the possibility of it breaking loose & releasing all of it's energy in an uncontrolled manner.  Its Bulkier, adds more weight to the vehicle.
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  Thank You…