Thomas,

 

 Referring to Monty's initial response I'd agree with most of his comments except #6, "look at hot day takeoff and climb. size max opening for that." I'd recommend look at hot day takeoff and climb, size 10 - 20% larger than what you think is required for that. In my opinion its easier/better for early flights to start out too large and have excess cooling than to start too small and possibly have an emergency or engine damaging situation on your hands on your first flight. For optimum performance it will require revision either way, but too big is less stressful during early flights. Its probably easier to shrink an inlet or outlet than to stretch one.

 

 As for your design, I understand the desire to start with a proven, engineered design. I'd bet that Monty is correct and there there was a lot more trial and error in the P-51 design than any of us realize. As for copying that design, I have two issues and I know I've stated this before so sorry for sounding like a broken record:

1) The shared inlet for both oil and water, while it looks better/cleaner, I doubt it is any more aerodynamically efficient. Using two entirely separate paths (in my opinion) will make troubleshooting and/or modification easier if either system tends to run too hot.

2) The configuration you are using (at least as depicted) demands a relatively thick radiator with a relatively small frontal area. I know several people have tried this approach - I'm not aware of any that were successful. A thick radiator using modern tube and fin construction is simply too restrictive to airflow.  I believe current thinking is that a thin radiator with lots of frontal area is better from both a cooling efficiency and a drag reduction viewpoint. Even if the airflow has to make several 90 degree turns to get through the core. At one point I had some data from a cooling system engineer who used to work for GM to show this, but that info is long since lost.

 

Mike Wills

RV-4 N144MW

From: Thomas Mann

Sent: Friday, January 29, 2010 9:32 AM

To: Rotary motors in aircraft

Subject: [FlyRotary] Re: Tiff to CAD Software

Ben,

This is a Long-EZ Hybrid so, yes the cruise speeds will be much higher than the Cessna style high wing designs.

 

As far as the amount of effort involved ……… I would have to say that you get out of it what you put into it.

I started with this:

 

….. and now I’m here:

 

My original post was to share a tool that I constructed to convert a graphics file to a CAD drawing to allow it to be manipulated. Once I have a final version of it, I’ll add it to my website for download (for those interested.)

 

T Mann