red baron record attempt 1979

[RandyGoss75]

Re: red baron record attempt 1979

Thanks Shawn!

Happy New Year to you and your family.........All the best, RG

[Peashooter]

Re: red baron record attempt 1979

So what could a "Baron for the new Millenium" do if it had re-profiled prop blades and boil-off cooling?

[First time Juke]

Re: red baron record attempt 1979

So what could a "Baron for the new Millenium" do if it had re-profiled prop blades and boil-off cooling?

I did think about that for a while recently...about the boil of cooling.

Ernst heinkel was denied to try another time with his He 100 V-8 after Me 109 R had set a new record. His kite did almost fly at the same speed with 500 less hp...when using boil off cooling. He 100 had also forward sweep and was considerably bigger than a 109 R.

Latest Heinkel design was to go 880 km/h ( 546 mph ) with boil off cooling and 8 degree forward sweep and some 2800 hp. That is 1000 hp less than RB used to get close to 500 mph.

Would it be plausible to think that boil off cooling credited some 40-50 % of that advantage and some 40% with forward sweep and rest ( 10-20% ) due to cleaner aerodynamics overall and possible weight reduction etc. ?

That was my educated guess.

This info is partially based on also a comment from a US combat model hobby pilot Mark McCool who said that his He 100 model went like "bat outa hell"...meaning; with incredible velocity.

[Red]

Re: red baron record attempt 1979

Juke

You gotta take the models performance with a huge grain of salt!

The model will not predict a full scale with any degree of reliability for a variety of reasons including reynolds numbers, scale sections etc., due to a 1/12th scale planes innability to accuratly replicate anything but a general outline. Models are easily overpowered as well. In that combat class (2610) you are allowed up to a 10% in scale outline deviation and up to .26 c.i. engines. This translates into very good performance for the size. Models can be very useful to validate a design concept though.

I'm curious about the performance #'s you posted, are they predicted or measured. If measued what were the conditions? Interested!

As for the "Baron it was one of my favorites and it was my first trip to Reno when she went in. I would love to see a modern version cruise the sticks again.

Red

[Shawn Aro]

Re: red baron record attempt 1979

Hey Randy Happy new year to you too were having a blezzerd tonight the wind his really blowing right now. Shawn

[First time Juke]

Re: red baron record attempt 1979

Juke

You gotta take the models performance with a huge grain of salt!

The model will not predict a full scale with any degree of reliability for a variety of reasons including reynolds numbers, scale sections etc., due to a 1/12th scale planes innability to accuratly replicate anything but a general outline. Models are easily overpowered as well. In that combat class (2610) you are allowed up to a 10% in scale outline deviation and up to .26 c.i. engines. This translates into very good performance for the size. Models can be very useful to validate a design concept though.

I'm curious about the performance #'s you posted, are they predicted or measured. If measued what were the conditions? Interested!

As for the "Baron it was one of my favorites and it was my first trip to Reno when she went in. I would love to see a modern version cruise the sticks again.

Red

I agree models tell very little unless they are pretty close to scale and all have same engines and foil adjusted for the right Reynolds number.

880 km/h is in the luft46 data . The record for 100 v-8 is in all books about it...including Green's Augsburg Eagle for instance.

100 V-8 was yet again smaller than the 109 G or those real fighters.

Juke

[AirDOGGe]

Re: red baron record attempt 1979

I agree models tell very little unless they are pretty close to scale and all have same engines and foil adjusted for the right Reynolds number.

No... Scale size/accuracy and engines used have nothing to do with it.


The problem is, you've scaled the plane down, but you haven't scaled down the air molecules that it has to pass through. Altering the model to try and compensate ruins the whole plan of testing the aircraft or airfoil confiuration as designed by the engineers.

There are a few tricks to circumvent this problem, by pressurizing a wind tunnel and chilling the air down to make it denser, but you'd have a hard time doing so on an RC airfield.


You'll find more info by reading this chapter of an excellent "book" about the creation of the various wind tunnels at NASA Ames Research Center and at other NASA facilities:


'The Variable Density Tunnel and Scale Effects'

http://www.hq.nasa.gov/pao/History/SP-440/ch2-8.htm

and this one about the high pressure tunnel at AMES:

http://www.hq.nasa.gov/pao/History/SP-440/ch4-3.htm

Since you are so fascinated with aircraft design and testing (as I am), I recommend after reading that chapter on Reynolds Numbers, click the INDEX link at the bottom and read the rest of the book (available online at NASA's history site). It's incredible the hurdles that had to be cleared, and how new technologies were conceived, created and developed by these gifted engineers to make wind tunnel testing work sufficiently in nearly all flight enviroments.

(P.S...I love this book because I spent a year at NASA Ames in one of their model shops, and have had the pleasure of examining many of these tunnels from the inside ;-) )

.

[First time Juke]

Re: red baron record attempt 1979

No... Scale size/accuracy and engines used have nothing to do with it.

I am thinking a wider aspect..the overall workability of basic layouts...certainly models don't have the molecules in miniature size.

[First time Juke]

Re: red baron record attempt 1979

Juke

I'm curious about the performance #'s you posted, are they predicted or measured. If measued what were the conditions? Interested!

As for the "Baron it was one of my favorites and it was my first trip to Reno when she went in. I would love to see a modern version cruise the sticks again.

Red

In Bill Sweetmans book High Speed Flight ( 1983 ) there is lotsa info about the forward swept wings.

RB is still the Fastest Piston AC when that book was new.