F4U, P-51, P-38, Starting

a F4U-1D, TF-51, and P-38 "glacier girl" all starting and taxiing at the Nellis AFB Air Show - Aviation Nation 2006

Category:

Autos & Vehicles

Tags:

• P-51
• F4U
• P-38
• Taxiing
• Aircraft
• Warbird
• Air
• show
• Aviation
• Fluegel
• Corsair
• Mustang
• Lightning
• Glacier
• Girl
• run
• start
• Nelli

[Logik426]

Why American warbirds like P-47 or P-51 have no camouflage? British and German fighters had always camouflage, but American didn't have... they were shiny with colour marks. Why??

[justinfluegel]

The correct reason that all these sofa historians are not telling you about is that by 1944 the skies over Europe began to run silent of enemy fighters. In an attempt to get german fighters to engage the Allied High Command for the US decided to remove the camouflage and go with a polished steel look. You notice this heavily on early war B-17's and late war B-17's.

[justinfluegel]

the nose of the aircraft retained the flat olive drab to prevent the pilot from seeing a massive glare.

[TJDOZIER1]

That Corsair looks like a F4U-1D model. There were no "G" models. The "G" associated with Corsairs designated aircraft built by Goodyear and were designated "FG" not F4.

The 3 bladed prop, dual antennas and 6 50 cal guns limit the model possibilities to an F4U-1

[justinfluegel]

thanks for the heads up... fixing now.

[Carstuff111]

@justinfluegel It isn't polished steel, it's polished aluminum, and its beautiful.

[zeekwolfe]

Thank you! Your explanation was lucid and knowledgable, written by someone with an engineering background. At slow wind speeds wouldn't four or five blades on a wind turbine work better than three?

Also, I was told that the TU-95 made so much noise because of prop speed that a couple of planes in formation could be heard on both sides of the Black Sea. That's pretty loud, I'm not sure I believe that.

[105PorterHouse]

(5)

As the power of engines increased over the years, engineers increased the number of propeller blades. Once they ran out of room on the propeller hub, they designed twin contra-rotating propellers on the same engine. Two such examples are the Russian Tu-95 bomber and Tu-114 airliner. They had some of the most powerful turboprop engines built and both feature a total of eight propeller blades per engine.

[105PorterHouse]

(4)

This leaves increasing the blade chord & increasing the number of blades.

Increasing the blade chord: Increases the solidity of the propeller disk. (Solidity is area of the propeller disk occupied by solid componenets (the blades) versus open area.) As solidity increases, so does efficiency. Although increasing the blade chord is an easy option, it decreases the aspect ratio of the blades, causing a loss of efficiency.

Thus, increasing the number of blades is most efficient approach.

[105PorterHouse]

(3)

Many of these options are impractical.

Blade angle - the pitch of the blade optimizes efficiency; changing the angle, costs efficiency.

Blade length - size constraints - landing gear must become longer, affecting structure & weight.

Revolutions per minute - as blade tips travel faster they become supersonic - forming shock waves - increasing drag, costing efficiency.

Airfoil camber - airfoils are chosen for efficiency, changing them costs efficiency & causes structural problems.

[105PorterHouse]

(2)

As engine power increases, there are limited propeller options to efficiently transfer the power:

Increase the pitch of the propeller blades.

Increase the propeller diameter (make the blades longer).

Increase the revolutions per minute of the propeller.

Increase the camber of the prop airfoil.

Increase the chord (width) of the propeller blades.

Increase the number of blades.

[105PorterHouse]

(1)

The job of the propeller is to transmit power from the engine to the air passing through the propeller disk. For efficiency, the propeller must be matched to the engine depending on the power of the engine.

[zeekwolfe]

Can someone explain to me in a lucid and knowledgable way why some airplanes have three bladed props like the F4U Corsair and others have 4 like the P51 Mustang. The British Supermarine had 5 blades, if memory serves. I've asked the same question about electrical generating windmills. I'm still waiting for some egghead to explain.