You
should be able to get flow rate; pressure drop; heat rejection rating from
Fluidyne. Based on my calcs, it would be good to about a steady 120 hp in
a rotary, if you get good air flow through it.
How can you calculate this
without the info you mentioned? How much air flow is
"good". What is the temp? I appreciate the thought, but I
don't really believe all the calculations in the world will give a real answer
when you consider all the variables. It might be interesting, and will
certainly be in the ballpark, but you won't really know how it works until you
try it.
I knew when I wrote it you didn’t
want to hear what I had to sayJ. And I didn’t say I was right, just based on my calcs
and comparisons, that was my judgement. I did the analysis for my
installation, and just scaled your fluidyne cooler off of that. Of course
the answer you get depends on your objectives and assumptions. I’d
like to be able to run a continuous 75-80% power on a 90F day at climb speed.
Yeah; a complete analysis is complex,
and beyond the tools that I have at my disposal. But back when I was
heading up an engineering analysis group, it was amazing what we did. A few
tens of thousands of dollars solved problems that hundreds of thousands of build
‘em and bust ‘em dollars would never solve. I’m just
fortunate to still have some of the simpler analytic tools at my disposal, so questions
like “how much flow is good?” aren’t too tough and gets you
in the ballpark pretty quick. Take the amount of heat you have to dump,
the specific heat of the fluid, and an approximate temperature change, and you
can calculate the flow rate right now. Actually getting that flow rate
through the heat exchanger may be the tough part.
Fluidyne has tested their oil cooler
cores and have heat rejection heat rejection rates, pressure drops, as a
function of flow rates, etc; it’s just tough to get them to give you the
data. I discussed it with one of their engineers years ago when I was
doing my design.
And you’re right; ultimately you
have to install it and test it. The simple analysis just increases the
odds of getting close on the first try.
Al