Engine Moment of Inertia
Engine Moment of Inertia
(OP)
I need a bit of help for a project I am currently working on, and hopefully somebody can help. I am trying to determine the moment of inertia of an engine by performing some sort of bench test. Does anybody have a test method for this? I was thinking along the lines of removing the valves/spark plug to reduce the pumping losses and make some sort of fixture that I could drop different weights to spin the crank and measure the time it takes the weights to drop a certain distance.
I think there would be too much error trying to calculate this using all of the component's masses.
-Reidh
I think there would be too much error trying to calculate this using all of the component's masses.
-Reidh





RE: Engine Moment of Inertia
However, if you want to do a physical test then your method won't really work. You'll mostly be measuring friction in the rings and valve gear. The accurate way to do a test is to suspend each component from a trifilar suspension and measure the frequency of the torsional mode.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.