Pacific Flyer: David Rose Story

[Kahuna]

Re: Pacific Flyer: David Rose Story

Why not Reno ?

If you are really fast enough there´s no need for sharp 4.1 G turns. A slightly wider and rounder line would fit in all deathlines and reduces the G loads. Do you remember that F-16 demo going around the course with 600 mph. ? Brute Power ! And there is also the Car Racing variant ! Hit the brake (throttle back) in the turn, Pedal to the metall (throttle firewalled) on the straits. Both versions would be different and requires a new style of flying but it is possible.
A 60 % bigger "Dago" is able to go faster than 500 mph. in Reno with around 4000 hp. Can you imagine how fast Roses Plane could go with 5000 hp.

Willy from Germany

[Bill Marsh]

Re: Pacific Flyer: David Rose Story

Bonneville facts check.... big inch "liners" , motors surviving @.....

Doing multiple runs, is max realistic power settings are a 2500 hp
> yes
> no
> esplain me , what it is

Doing multiple runs, is the realistic power setting @
> 5 minutes
>10 minites
> esplain me again

Bmarsh

[Bill Marsh]

Re: Pacific Flyer: David Rose Story

Mountain motors (rats) are exceeding the 800 cu " displacement....

are they for a/c ?


...... humm

BMarsh

[jarrodeu]

Re: Pacific Flyer: David Rose Story

Eric, Good to see you posting!

Jarrod

[bergschrund]

Re: Pacific Flyer: David Rose Story

I agree with Kahuna. Rose's plane could still be fast enough around the pylons if he took a slightly wider route. Potentially he would have more than enough power to make up the difference. I fully expect the Pacific Flyer to compete someday if RARA doesn't change the rules again. B

[Blue Foam]

Re: Pacific Flyer: David Rose Story

Rose's plane could still be fast enough around the pylons if he took a slightly wider route. Potentially he would have more than enough power to make up the difference.

We need to understand the flight physics here. A wider line is a longer distance, which requires more speed and more G. The lowest G is at a constant .964 mile radius (maps are great things...).

Since there is over 6 miles of turn and this is over 70% of the course, we can't "make it up in the straights". If anyone wants to fly a 500 mph lap, the least G they can pull in a level turn is 3.44. The turn from pylon 1 to 3 is climbing, so that one is over 4. Go wider and it's slower. Go fast enough on a wider line to make the same lap speed and we would actually pull more G, not less.

Gust loads have been routinely reported to be +/- 2 to 3 more G, so we really need to keep the lift coefficient around .4 to .5 to have some margin and not slow down with every little bit of turbulence. If he's using modern props, we can figure that his wing airfoils are pretty modern too and could have a buffet Cl limit of .6 to .7. The gust loads and the speed would require .8 to 1.0. Bottom line, it really needs more wing for the pylons.

On another note, we have to ask where all the fuel volume is and how many minutes it can stay up. The Bear and some of the other Unlimiteds are pretty limited in this area, but have lots of un-used volume. I expect that Rose has a big fuel cell in the center of the fuselage (on the CG). The weights only show an 800 lb allowance for fuel (200 lb pilot) so if we had a REALLY GOOD specific fuel consumption for race motors of .5, we would get 5000 HP for 19 minutes. Getting 2500 HP on gas is pretty thirsty work. On methanol, figure an SFC of .8 to .9 or about 11 to 12 minutes at power.

I believe that with the size of the aircraft, he only needs about 2000 HP to do a 500 mph lap, and that would be 48 minutes on gas or 27 to 30 minutes on methanol. After accounting for takeoff and landing and the short duration of a race, figure it's good for 60 minutes from wheels up to wheels down.

[wyhdah]

Re: Pacific Flyer: David Rose Story

Incase anyone wanted to know what a 3000hp turbo motor looks like.

[Kahuna]

Re: Pacific Flyer: David Rose Story

A constant radius of 0.964 mi. at 500 mph pulls 3.28 G !
A constant radius of 1.100 mi. at 500 mph pulls 2.87 G !

When calculated for a constant G (3.28) the speed for 0.964 mi. radius is again 500 mph. and the speed for 1.1 mi. radius is 533.9 mph.

hmmm. "The lowest G is at a constant .964 mile radius"

tell me why !

Willy

[shadow]

Re: Pacific Flyer: David Rose Story

Here is your quote from 2006, Shadow;

"904ci DOHC 1200HP on pump gas. Add boost and you have 2000HP, add ADI and race gas and you have 2500HP+.

www.schubeckracing.com"


Are you saying that this guy's motors are better than the one's Dave is using, or are you talking out of your hat?

Out my ass.

After everyone criticized me in 2006 for that very same statement you dug up. I did some research. A lot of research actually. What I learned of Kinematics of currently operating aviation engines lead me to realize the Shubeck 904 would not last at 1200hp for very long. The rpms the engine would have to run to achieve that output are much too high for any extended use. I can't remember off-hand what the rated rpm of the schubeck are but they must be over 5250. Neither can I really recall what rpm the schubeck would be limited to for extended use. I think it was less than 3500rpm. This cut the output significantly, I think I fudged the it to 650hp. Add boost, adi, race gas and you're back to 1300hp or so.

To flesh this out more, the 'Dart' headed engines are said to be BBCs, so that implies 500-600ci. That's 2/3 the shubeck or 867HP. Perhaps my estimate of 1000HP from each Dart-headed-BBC was too generous even.

Over the past year I seem to have lost the pie-in-the-sky attitude and come back down to earth somewhat. Hopefully the pain of the fall simply isn't creeping out of me now and hurting others.

Also, are you an engineer in the specialty of thermal engineering? Your statement seems pretty concrete about the absolute certainty that Dave Rose's concept isn't going to cut the mustard.

Actually I do have some thermal engineering background... but that is not why I claim that his surface cooling will not work. It's that he's taking a concept that has never worked as advertised historically and is betting the farm on it. So many intelligent men, so many hours of research, so much money has been spent on this, so how is Dave Rose supposed to all of a sudden do what no others have done and pull it off? Memory may fail me, but the surface cooling systems used before were for smaller engines on larger wings.

The best way to describe me is as a copious consumer of information. I research things heavily. Everything that I have read tells me that Dave is stacking the deck so high against him that this project was dead even before he started to build the jig.

If he would have taken two io540s, a couple of hartzell propellers spec'd for contra-rotating use, and added normal cooling that he could have blocked off at a later date once it was determined that the surface cooling was adequate, then maybe then I would expect the project to have a chance of making it in a few years.

Everything takes time and resources to get right. Props, drive mechanism, cooling, engines. Each one of these can tie up the project indefinately, especially if it's being funded by Dave himself.

I'm all for innovation of the little guy, and it's true, a great many innovators were individuals with a dream. However, for this project to succeed he must become an innovator in engines, props, drive mechanisms, and cooling. That's four huge innovations from one guy all at the same time.

PS: this was quick, I'll probably edit it at a later date.

[5150]

Re: Pacific Flyer: David Rose Story

From Wayne's link in the original post, they are expecting to have it running in July and flying in late August. I've tried looking around for more information, but haven't been very successful.
I'd LOVE to hear what it sounds like! I've heard tandem V8's before, but not coupled to counter rotating NASA designed unducted fans. That should add a very distinctive note to it.
Anyone have anymore information/links!?!?

[Kahuna]

Re: Pacific Flyer: David Rose Story

Quote: Memory may fail me, but the surface cooling systems used before were for smaller engines on larger wings.

It has been done before, In line Twin Engine, Contra Rotate, Big Engines and surface cooled on a basically Wood and Fabric Plane.
Macchi MC.72 1933 !
Yes it was successful, this speed record stands still ! 709.209 km/h (440 mph.)

[Bob]

Re: Pacific Flyer: David Rose Story

Thats a pretty slow record to still be standing. I wonder what Rare Bear would look like with poontoons.........

[Leo]

Re: Pacific Flyer: David Rose Story

For most of the Schneider racers, any kind of flat radiator stuck into the airstrean seems to have been poor form, and definately not a feature on the winners.
EVERY surface was used, the wings, the floats, the stabs and the sides of the fus. Wonderful studies in streamlining.

[Leo]

Re: Pacific Flyer: David Rose Story

I remember drawings of Tsunami with floats. It was one of the records she was built for.
I don't think the record will be broken. There is just no other concievable use for a 400+ mph float plane except for racing.
Bring back the Schneider Cup?

[wyhdah]

Re: Pacific Flyer: David Rose Story

Quote: Memory may fail me, but the surface cooling systems used before were for smaller engines on larger wings.

It has been done before, In line Twin Engine, Contra Rotate, Big Engines and surface cooled on a basically Wood and Fabric Plane.
Macchi MC.72 1933 !
Yes it was successful, this speed record stands still ! 709.209 km/h (440 mph.)

That's a beautiful plane.