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Ed,
Some of us real "radical" rotor heads are using the 2.85:1 ratio drive. I was wondering if you could modify your spreadsheet model to allow other drive ratios? This may help some of us to better model our systems and make the proper choices for the other system components.
Thanks,
Jim Maher
(Dyke Delta/13B)
--- Original Message ---
From: "Ed Anderson" <eanderson@carolina.rr.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: [FlyRotary] New cooling Model example
Ok Folks,
I've been messing around with the cooling model of the spreadsheet that
some of you have.
I don't want to send out dozens of spreadsheets which are in the development
phase and have 47 different version out there. So I am only going to send
out some results of the latest models in the spreadsheet and ask for
comments.
Once it appears that the model is approaching some degree of realism and
usefulness, then I will be happy to provide everyone with it.
Right now, I am concentrating on the evaporator core
models. However, my
intention - if it works out with the cores - is to broaden this so other
folks not using the cores can make use of it as well.
I realize that some of you may not have much more insight into what
"realistic" might intale than I do, but I have a great deal of faith in the
keen analytical minds out there to provide some useful input (How about that
for stroking the egos{:>))
I have attached a spreadsheet with the results of three cases using the
model. The all involve an aircraft taking off in early climb out producing
150 HP. The three cases involve climb out, high power and low airspeed.
Case 1. Climbout is made on a 20F day with 150HP at just fast enough
airspeed to provide minimum adequate cooling. Case2. Climbout is made on a
90F day with the same power and airspeed conditions as case 1. The model
shows the cooling capacity is exceeded. Case 3. Then holding everthing the
same as case 2 including power and 90F OAT, I increase the airspeed (and
therefore mass flow) until at 117 MPH we again barely achieve adequate
cooling on the 90F day. Note that the delta T changes for each case.
There are some comments and notes with each case.
Take a look and if
inclinded I would greatly appreciate any feedback.
Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com
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