- #1
Peter.B
- 5
- 0
Hi all,
I am trying to compare the heat input into an engine with useful work out. I have taken a measurement for Torque, and have calculated heat input per cylinder based on combustion calculations i.e throttle % x cal value of fuel x fuel mass.
I am happy with the heat input calculation per cylinder, but am having difficulty establishing how overall work done and heat input per cylinder align.
* 3000 RPM
* Torque = 27.7
* Revs /Sec = 50
Work Done
Power = (Torque*((2*3.14)*Revs))
=(27.7*((2*3.14)*50))
= 8698 Watts
However when I compare this to the heat input, the heat input is much lower?
Heat input per cylinder per 2 cycle (i.e 2 revolutions of crank) = 237 Joules (I am 99% confident that this value is correct).
Heat input Power = (236 x 50 ) / 2 (Divide by 2 because heat input every 2 revs)
= 5926 Watts ??
The question I have is... Should I be taking into account the heat input to all cylinders? or is there some other fundamental thing which I am missing?
If anyone could point me in the right direction it would be much appreciated.
Thanks,
Peter
I am trying to compare the heat input into an engine with useful work out. I have taken a measurement for Torque, and have calculated heat input per cylinder based on combustion calculations i.e throttle % x cal value of fuel x fuel mass.
I am happy with the heat input calculation per cylinder, but am having difficulty establishing how overall work done and heat input per cylinder align.
* 3000 RPM
* Torque = 27.7
* Revs /Sec = 50
Work Done
Power = (Torque*((2*3.14)*Revs))
=(27.7*((2*3.14)*50))
= 8698 Watts
However when I compare this to the heat input, the heat input is much lower?
Heat input per cylinder per 2 cycle (i.e 2 revolutions of crank) = 237 Joules (I am 99% confident that this value is correct).
Heat input Power = (236 x 50 ) / 2 (Divide by 2 because heat input every 2 revs)
= 5926 Watts ??
The question I have is... Should I be taking into account the heat input to all cylinders? or is there some other fundamental thing which I am missing?
If anyone could point me in the right direction it would be much appreciated.
Thanks,
Peter