Wing attachment and a spinner !

[First time Juke]

Two questions about wing and spinner !

First the wing thing.

Thunderbolt and Me 109 both had wings attached to the fuselage from their spars with bolts. Mustang and Tsunami had a whole wing sorta integrated from below to the fuse.
What pros and cons are there ?

Then the spinner.

I recall Bearcat originally flew top speeds at 660 km/h and Rare Bear top speed was 850 km/h. Superficially the Bear only looks to have a new spinner, engine, prop and canopy....wingtips are clipped and fuse extended !
How much of the increased speed is owed to the spinner ? I recall later model Brewsters had also a considerably bigger spinner..what was gained with the new spinner ?

later,

Juke

[Race5]

Re: Wing attachment and a spinner !

I think that would fall into the total design of the air frame. The Mustang could probably have been built with a bolt on wing, but the fuselage structure might have been such that other things might not fit where the designers intended. I don't think strength is a problem either way. For example the wing of a B-52 bomber is only held in with four bolts.

[Blue Foam]

Re: Wing attachment and a spinner !

A continuous spar is lighter for a given strength than a bolted attachment. The bolt on wings are usually an artifact of either manufacturing efficiency, transport requirements, or both.

The Bf-109 was manufactured as a fuselage on its gear until it got out the door, then the wings went on. Saved a lot of floor space in the factory.

MiGs have bolt on everything so that they can be crated and shipped instead of flown on long range ferry flights.

Virtually all Naval and Marine aircraft fold their wings for storage on the flight and hanger decks. This results in the second greatest weight penalty to a "carrier capable" aircraft, first is arrested landing structure and landing gear, third is catapult launch capability.

[Blue Foam]

Re: Wing attachment and a spinner !

Superficially the Bear only looks to have a new spinner, engine, prop and canopy....wingtips are clipped and fuse extended !

later,

Juke

Only??? Over half of the aircraft's empty operating weight is not stock. Rare bear is arguably the MOST modified of all of the warbird unlimiteds.

[matt]

Re: Wing attachment and a spinner !

juke, in my two years with rare bear, i had a lot of oppurtunity to study mods on the airplane that you normally wouldn't notice in pictures, spend time just studying pictures of the bear and a stock bearcat, from all angles.

[First time Juke]

Re: Wing attachment and a spinner !

Only??? Over half of the aircraft's empty operating weight is not stock. Rare bear is arguably the MOST modified of all of the warbird unlimiteds.

Eric,

What I mean is that there are other mods too. Engine thrust axis is straight when original has engine vectored down...etc.

Juke

[Blue Foam]

Re: Wing attachment and a spinner !

Eric,

What I mean is that there are other mods too. Engine thrust axis is straight when original has engine vectored down...etc.

Juke

I hate to say this, but that's pretty irrelavent. The relevent modifications are the wing clip and DC-7 engine and cowl. It all comes down to HP vs. wetted area.

In 2000, I saw the Bear in the same hanger with a Lancair IV and Riff Raff. I joked to my partner that the Lancair could fit inside of the Bear and the Bear could fit inside of the Sea Fury. Rare Bear performs for the same reasons that the original F8F performed: lots of engine, little airplane. The Bear has a 2000 to 4000 lb advantage over the Sea Furies with 34% less wetted area and more power than anyone except Critical Mass. Although people seem to think that the Bear is some kind of monster, She has exactly the same wetted area as Dago. It is only a small amount of separation drag that keeps her behind the fastest Mustang. Cure this and no MMM (mouse motor mustang) could touch her.

[AAFO_WSagar]

Re: Wing attachment and a spinner !

It is only a small amount of separation drag that keeps her behind the fastest Mustang. Cure this and no MMM (mouse motor mustang) could touch her.

Sure wish someone would fix that for them Eric....

Wayne

[First time Juke]

Re: Wing attachment and a spinner !

Sure wish someone would fix that for them Eric....

Wayne

I assume the separation is caused by the nonlaminar foil of the Rare Bear. Fixing that would most likely also alter the flight caracteristics. Stall would become vicious..like in a Mustang.

rgds,

Juke

PS: I am not an aerodynamist by profession ( that is why I assume ).

[matt]

Re: Wing attachment and a spinner !

juke, laminar flow is generally only a good thing on long stretches, original p-51's had laminar flow to help conserve fuel (higher straightaway speed verses a normal airfoil's reduces fuel consumption since the airplane can fly at a higher speed with a lower power setting) on long bomber escort missions. but notice the airfoil on dago red, strega, voodoo, etc. that the wings have been glassed and that laminar flow airfoil is now a much more conventional design.

i'm not sure exactly what the reason is that they fill the laminar flow section of the wing in (eric please help). but as i understand it it would not help much to give the bear a mustang airfoil (let's say a maximum of 20 mph gain on race power setting for cash in the $500,000 to $1 million range), the sea fury's is actually a better airfoil to go with, if you're going to use ww2 airfoils.

something i just thought of though, if the mustangs wing is only so much better than a bearcats' would a *new* wing be feasible? and if rare bear gets a new wing would a mustang need a new airfoil of it's own to keep up?

[Blue Foam]

Re: Wing attachment and a spinner !

[QUOTE=Juke]I assume the separation is caused by the nonlaminar foil of the Rare Bear. Fixing that would most likely also alter the flight caracteristics. Stall would become vicious..like in a Mustang. QUOTE]

OK, let's kill two misperceptions with one post.

All airfoils with smooth surfaces achieve some amount of laminar flow. The Bear has about 15% of it upper surface and 60% of its lower surface in laminar flow. For Dago, this is about 40% upper and 50% lower. This is not a relavent difference between the two aircraft.

Separation and stagnation are greater on the Bear than Dago because of poor intersection design. I have written articles here about that and am writing a comprehensive one now.

As to airfoils with extensive laminar flow, some have hard stall issues, some do not. Never assume.