Minimum Cooling Requirements
04-12-2002 | 11:58 PM
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From: MelbourneVictoria, AUSTRALIA
Minimum Cooling Requirements
Are there any figures available for the minimum inlet/outlet areas required to adequately cool a US41?
In a tightly cowled installation I have the following available without cutting holes in the cowling:-
900 sq mm inlet area
1.395 sq in
3768 sq mm outlet area
5.84 sq in
The air can be baffled to pass directly through the fins.
Would appreciate any info.
--
Merlin
In a tightly cowled installation I have the following available without cutting holes in the cowling:-
900 sq mm inlet area
1.395 sq in
3768 sq mm outlet area
5.84 sq in
The air can be baffled to pass directly through the fins.
Would appreciate any info.
--
Merlin
04-15-2002 | 10:50 AM
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From: Tuscola,
IL
Minimum Cooling Requirements
Merlin,
There are no min/maxes, no. the #1 rule, however, is to have AT LEAST 3 times the outlet as you have inlet. If you baffle your inlet can be that much smaller, but the outlet must still be at least 3 times that inlet.
Sincerely,
Mrs. AnnMarie Cross
Senior Manager, Proprietary Services and Support
Great Planes Model Distributors
[email protected]
www.greatplanes.com
www.bestrc.com
NO AUTORESPONDER
There are no min/maxes, no. the #1 rule, however, is to have AT LEAST 3 times the outlet as you have inlet. If you baffle your inlet can be that much smaller, but the outlet must still be at least 3 times that inlet.
Sincerely,
Mrs. AnnMarie Cross
Senior Manager, Proprietary Services and Support
Great Planes Model Distributors
[email protected]
www.greatplanes.com
www.bestrc.com
NO AUTORESPONDER
04-15-2002 | 12:00 PM
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From: MelbourneVictoria, AUSTRALIA
Minimum Cooling Requirements
Dear AnnMarie,
Thank's for the quick and valiant effort to answer this question.
Unfortunately I am still none the wiser as the 1:3 ratio rule is well known.
If this formula is correct then a 1 sq mm inlet would suffice as long as the outlet was 3 sq mm. Clearly this is not the case.
It would appear that US Engines has not established a minimum inlet area and I'd be surprised if any other maker has either.
If I can establish this data somehow, I'll be sure to pass the info on to you.
Many thanks,
Merlin
Thank's for the quick and valiant effort to answer this question.
Unfortunately I am still none the wiser as the 1:3 ratio rule is well known.
If this formula is correct then a 1 sq mm inlet would suffice as long as the outlet was 3 sq mm. Clearly this is not the case.
It would appear that US Engines has not established a minimum inlet area and I'd be surprised if any other maker has either.
If I can establish this data somehow, I'll be sure to pass the info on to you.
Many thanks,
Merlin
04-15-2002 | 12:03 PM
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From: Tuscola,
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Minimum Cooling Requirements
Thanks Merlin!
Most modelers are unaware of the 3:1 rule (believe it or not!) and many mistakenly believe that more inlet can only be better without increasing outlet.
Sorry, no, i have never seen a set figure. I know at least for the aerobatic aircraft we work with it varies drastically by aircraft and we determine it based on flight performance of the model.
Most modelers are unaware of the 3:1 rule (believe it or not!) and many mistakenly believe that more inlet can only be better without increasing outlet.
Sorry, no, i have never seen a set figure. I know at least for the aerobatic aircraft we work with it varies drastically by aircraft and we determine it based on flight performance of the model.
