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karan_s

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I need to work out how long the engine will run at its top speed using a air pressure which is supplied from a compressed air tank.Compressed air pushed down a piston which is connected to a camshaft. As the piston reaches bottom, a slot opens allowing the air in the chamber to escape and for the piston to come back up again.A second piston will eventually be added which helps the first piston come back up using the air that is released.

For now I am just doing calculations for the first piston.Weight of go kart including driver and tank: 200kg

Compressed air pressure pushing piston down: 8 bar

Max engine speed: 1500 RPM - 17 MPH max driving speed

Piston stroke: 60mm

Piston bore: 62mm

Crankshaft radius: 19mm

Weight of piston: 100g

Min acceleration to top speed: 6 secondsCould someone please explain how long this engine would run on a 500L tank of compressed air? This is assuming that the air is supplied at a constant pressure.

I have attempted it below but do not think its correct and am not sure what to to next.

1500 rpm = ω = 157 rad/s

α = ω/t , t being the time needed to reach the max rpm.

α = 157/6 = 26.16 rad/ sec^2

I = 1/2(200)(0.019)^2 = 0.361 Kgm^2

τ = I x α = 0.361*26.16 = 0.94437 Nm

τ = F x r

0.94437 = F x 0.019 So, F = 49.703NThanks in advance