Concept:
Flywheel:
- A flywheel is used to control the variations in speed during each cycle of an engine.
- A flywheel attached to the crankshaft makes the moment of inertia of the rotating parts quite large and thus, acts as a reservoir of energy.
- The maximum fluctuation of the energy of flywheel is given by:
ΔE = Iω2Cs
where,
I = Moment of inertia of the flywheel, ω = Mean speed
Cs = Coefficient of fluctuation of speed = \(\frac{{{\omega _{max}}\; - \;{\omega _{min}}\;}}{\omega}\)
Calculation:
Given:
ΔE = 2600 J
N = 200 rpm
\(\therefore \omega = \frac{{2\pi N}}{{60}} = 20.944\frac{{rad}}{{sec}}\)
ω1 – ω2 = ± 0.5% ω
\(\begin{array}{l} ⇒ \frac{{{\omega _1} - {\omega _2}}}{\omega } = \pm 0.5{\rm{\% }} = 1{\rm{\% }} = 0.01\\ \therefore {C_s} = \frac{{{\omega _1} - {\omega _2}}}{\omega } = 0.01 \end{array}\)
ΔE = Iω2Cs
⇒ 2600 = I × (20.944)2 × 0.01
⇒ I = \(\frac{{2600}}{{4.38}} = 592.76\;{\rm{kg}}.{{\rm{m}}^2}\)