- #1
Tom Booth
- 61
- 2
If a heat engine converts heat into "work", will ice used to run a Stirling heat engine last longer than ice allowed to melt by itself?
To try and answer this, I obtained a Stirling engine and ran this experiment:
With the engine running:
And not running:
Without the engine running the ice melted in 28 hours. With the engine running, it took five more hours (33 hours) for the ice to melt.
Conditions could not be held completely constant, the wether got a little cooler during the time when the engine was not running.
Only one engine was used, running and then not running consecutively rather than concurrent.
One person on a Stirling engine forum predicted that the ice would melt faster when used to run a heat engine because the engine would be actively transferring heat from one side of the engine to the other, taking heat from the warm side and transferring it to the ice, but the results of this test were the opposite.
Someone else on another physics forum recently predicted that the ice would melt faster without the engine running due to "reversability". I don't entirely understand exactly what that means or if it is a valid explanation of the results.
28 hours is just about 15% less than 33 hours, but still seems significant to me.
Is this result what should be expected?
If possible I would like to see others perform the experiment to see if they get similar results.
I plan on running additional experiments also, but only using single ice cubes, as this took over 60 hours using full cups of solid ice. It took the ice much longer to melt than I had anticipated for both instances.
To try and answer this, I obtained a Stirling engine and ran this experiment:
With the engine running:
And not running:
Without the engine running the ice melted in 28 hours. With the engine running, it took five more hours (33 hours) for the ice to melt.
Conditions could not be held completely constant, the wether got a little cooler during the time when the engine was not running.
Only one engine was used, running and then not running consecutively rather than concurrent.
One person on a Stirling engine forum predicted that the ice would melt faster when used to run a heat engine because the engine would be actively transferring heat from one side of the engine to the other, taking heat from the warm side and transferring it to the ice, but the results of this test were the opposite.
Someone else on another physics forum recently predicted that the ice would melt faster without the engine running due to "reversability". I don't entirely understand exactly what that means or if it is a valid explanation of the results.
28 hours is just about 15% less than 33 hours, but still seems significant to me.
Is this result what should be expected?
If possible I would like to see others perform the experiment to see if they get similar results.
I plan on running additional experiments also, but only using single ice cubes, as this took over 60 hours using full cups of solid ice. It took the ice much longer to melt than I had anticipated for both instances.