'Radiator Drag Is Modelled' - Demo

[hegykc]

Originally Posted by KDN

At 50% radiator open the plane speed increased? Any possible explanation it became more aerodynamic

Yes. On the P-51 the radiator, because of the hot air going out of it, didn't cause any drag at all, instead it even produced some thrust.
Saw that in a documentary.

[ATAG_Dutch]

Originally Posted by hegykc

Yes. On the P-51 the radiator, because of the hot air going out of it, didn't cause any drag at all, instead it even produced some thrust.
Saw that in a documentary.

Quite correct. This is known as 'The Meredith Effect' and the Spitfire was one of the first aircraft designed to incorporate a radiator housing designed to produce this effect.

[hegykc]

Oh thanks, didn't know the affect had a name, I thought it was by accident.
After some googleing:

"In the case of the
Mustang, this jet of heated cooling air reduced cooling drag to almost
nothing. It did not eliminate it entirely, but it reduced it to the
point where cooling drag was merely "3% of the thrust of the
propeller."

[ATAG_Dutch]

Originally Posted by hegykc

"In the case of the
Mustang, this jet of heated cooling air reduced cooling drag to almost
nothing. It did not eliminate it entirely, but it reduced it to the
point where cooling drag was merely "3% of the thrust of the
propeller."

That's very interesting information mate, thanks for posting!

Originally Posted by ATAG_Dutch

Quite correct. This is known as 'The Meredith Effect' and the Spitfire was one of the first aircraft designed to incorporate a radiator housing designed to produce this effect.

Except, at speed, the Spitfire (and 109 for that matter) had trouble with the ducts stalling and losing the effect. That's why, when the Mustang came over and proved to be so fast there was tremendous interest in the laminar wing, as it seemed the speed couldn't be due to the problematic duct effect. Real world experience, however, proved the difficulty of maintaining laminar flow in practice (Langley also doubted its field practicality). According to Lee Atwood, only two WW2 aircraft really made the Meredith effect pay off, and that was the Mustang and Mosquito and this was the biggest secret to their speeds.

[TomcatViP]

Originally Posted by ATAG_Dutch

Quite correct. This is known as 'The Meredith Effect' and the Spitfire was one of the first aircraft designed to incorporate a radiator housing designed to produce this effect.

Lol... all that for this.

Rectification: "one of the first aircraft [that you may know] designed to incorporate" and blablabla...

Secondly: Supermarine had no idea of what was a boundary layer and in particularly bellow the wing. This is why the Spitfire rads are so deep in shape compared to their German's counterparts or latter US design.

Hve fun

[ATAG_Dutch]

Originally Posted by TomcatViP

Lol... all that for this.

Not at all Tom. It wasn't me who brought up the topic of the Meredith Effect. Posters in other threads seemed to think that drag in radiators wasn't currently modelled.

The video demonstrates that drag from the radiators is modelled.

[MadTommy]

Good info thanks Dutch.

Originally Posted by TomcatViP

Lol... all that for this.

Rectification: "one of the first aircraft [that you may know] designed to incorporate" and blablabla...

Secondly: Supermarine had no idea of what was a boundary layer and in particularly bellow the wing. This is why the Spitfire rads are so deep in shape compared to their German's counterparts or latter US design.

Hve fun

Might i suggest if you want to be disparaging of others you should at least write one sentence that makes sense in the English language, then people might have some idea what you are talking about.

[TomcatViP]

Will write it in French if you don't mind MadGenius