The turning moment diagram for a four stroke gas engine may be assumed for simplicity to be represented by four triangles, the areas of which from the line of zero pressure are as follows: - Suction stroke $=0.45 \times 10^{-3} m^2$ , compression stroke$= 1.7X 10^{-3} m^2$ , Expansion stroke $= 6.8 X 10^{-3}m^2$ ,v Exhaust stroke $= 0.65 X 10^{-3} m^2 Each $m^2$ of area represents 3 MN-m of energy. All the areas except expansion stroke are negative. Assuming the resisting torque to be uniform, Find the mass of the rim of a flywheel required to keep the speed between 202 and 198rpm. The mean radius of the rim is 1.2m. - Mumbai University > MECH > Sem 5 > Theory Of Machines 2

Marks: 10 M

Year: Dec 2014

Given:

Maximum and minimum speed = 202 rpm and 198rpm

R= 1.2m

Solution:

Mean speed = (202 + 198) / 2 = 200

Therefore, fluctuation of speed = +/- 1% …i

But fluctuation of speed is given by

$\pm \bigg(\dfrac{\Delta E}{2I \omega 0^2}\times 100 \bigg) \%$…ii

Where

$∆E$ is energy …