On the Meredith Effect

[pbehn]

Welp, Mitchells Type 232 patrol flying boat had 4 Rolls Royce Goshawks, and the condenser inlet was the entire leading edge. Will Green stated in the Heinkel chapter on the 119 that the engine(s?) were evaporative.

I was thinking more of the Mosquito and other later air cooled engines which had the oil cooler inlet in the leading edge.

 

[maxmwill]

I realize that. And yes, it is a lot more complicated than that, especially in practice. You could call my approach to this more of a cocktail napkin guesstimate than anything more educated than that.

The radiator for this wouldn't be all that difficult to design, just take a page from Germany with the annular radiators, but it'd still be quite the bear to wrestle, from the intake type, to the radiator, to the entire plumbing arrangement.

And, upon further reflection, perhaps a full size replica of a Do-26, re-designed for a set of turboprops, and plying the Carribean might be a more realistic endeavor for consideration. Be kinda interesting if a water taxi service using such a replica were to be started up.

 

[maxmwill]

I was thinking more of the Mosquito and other later air cooled engines which had the oil cooler inlet in the leading edge.

No, the 232 was to have a full span slot.

Have a dumb question: If I can get my wife's scanner/printer/copier running, could I scan and post things here, such as a 3 view of the Type 232, along with its background, straight from the book? Or would I have to get prior permission from the mods here? I've found a lot of stuff, such as the Type 232, which are not on the internet, and I'd like to share it.

 

[pbehn]

No, the 232 was to have a full span slot.

.

Are we discussing evaporative cooling which was never used in practice?

 

[maxmwill]

Yes. I'd been wondering if the He-119, being evaporative cooled, might've benefited from an annular slot for the condensers, aft of the cockpit, with a common exhaust, and began to wonder if this might've had the Meredith Effect in action.

 

[MACHIA]

The P-40 inlet/outlet design was high drag . What was the error there ?

 

[Shortround6]

The P-40 inlet/outlet design was high drag . What was the error there ?

Was it?

The plane went considerably faster with the "chin" radiator than when they had the radiator in a Hurricane position. There were at least two attempts to change the radiator after that.
An experimental P-40F

the XP-40K

Now please note that by the time they were finished with the P-40Q the radiators were outboard of the landing gear and the oil cooler was back in the nose.
No performance figures seem to be commonly available for these experimental aircraft. Curtiss (and the Army) may not have been happy with the P-40s radiator but they don't seem to have been able to improve on it enough to warrant a change in production?

 

[pbehn]

Was it?

The plane went considerably faster with the "chin" radiator than when they had the radiator in a Hurricane position. There were at least two attempts to change the radiator after that.
An experimental P-40F
View attachment 508006
the XP-40K
View attachment 508007
Now please note that by the time they were finished with the P-40Q the radiators were outboard of the landing gear and the oil cooler was back in the nose.
No performance figures seem to be commonly available for these experimental aircraft. Curtiss (and the Army) may not have been happy with the P-40s radiator but they don't seem to have been able to improve on it enough to warrant a change in production?

Great post, for me it shows how difficult it is making major changes after a design is in production.

 

[Bottlehead]

I think you have to look at the patents covered by TP de Paravicini under GB entries. He covered aircintake on wing edges as well as the chin and or underbelly housing. All were in the 1936-8 period. He covered air cooled as well as liquid cooled engines.

 

[chuter]

Both the Spitfire and the 109 (the F in particular) attempted to make use of the Meredith effect but in both cases failed due to the stalling of the inlet duct at high speed. Lee Atwood was of the opinion that this was likely due to the duct system being forced into too small of the available volume in the respective wings making the duct diverge too quickly.

 

[Bottlehead]

See patent GB472555,& GB472334A

 

[pbehn]

See patent GB472555,& GB472334A

Any particular reason?

 

[Zipper730]

The P-40 inlet/outlet design was high drag . What was the error there ?

The XP-40 was much worse than the production models. It managed a top speed of only 315 mph which is 3 mph slower than the P-36's (some sources say 335 mph however). When they repositioned the radiator forward into a chin position top speed went up to around 352 by the P-40B.

 

[Bottlehead]

Any particular reason?

Yes. It was TO de Paravicini who rightfully should be credit with negative drag. As he was at the Farnborough Aircraft establishment when he write the original paper. Metedith was a fellow engineer.
But de Paravicini had the better math skills to prove it.

There are several patents in his name as to cooling and exhaust ejectors for improving aircraft.

He was hired as the youngest member of the Royal Aeronautical Society to help Rowledge the senior engineer at Rolls Royce.

 

[pbehn]

Yes. It was TO de Paravicini who rightfully should be credit with negative drag. As he was at the Farnborough Aircraft establishment when he write the original paper. Metedith was a fellow engineer.
But de Paravicini had the better math skills to prove it.

There are several patents in his name as to cooling and exhaust ejectors for improving aircraft.

He was hired as the youngest member of the Royal Aeronautical Society to help Rowledge the senior engineer at Rolls Royce.

Yes you told me that before, can you give me something to read and not just tell me there is interesting stuff to read if only I knew the link.

 

[Bottlehead]

Yes you told me that before, can you give me something to read and not just tell me there is interesting stuff to read if only I knew the link.

Merely that History gets edited and sometimes the rightful attributes get rubbed out.

Hence trying to get credit where it is due.

Studying the patents gives you an insight as to how negative drag works and how aircraft adapted the methods.
Some of his papers are in the Royal institution and I don't have access to them.

 

[pbehn]

Merely that History gets edited and sometimes the rightful attributes get rubbed out.

Hence trying to get credit where it is due.

Studying the patents gives you an insight as to how negative drag works and how aircraft adapted the methods.
Some of his papers are in the Royal institution and I don't have access to them.

You could of course give your take on what you read but don't have access to. I know how reduction of cooling drag works.

 

[TinyTim63]

I realize that, because the powerplant used in it was very similar to the Rolls Royce Goshawk, which was also an evaporatively cooled engine. And look at how successful that was. I'm not sure, but did the Germans try this on other aircraft, other than the He100 fighter? The British used this on a number of flying machines built, and was also proposed for such designs as RJ Mitchell's design for the Type 232, his contribution being a gull winged four engine patrol flying boat of the Sundeland class. In this case, the intake for the condensers being the entire leading edge of the wings.

My thought is if something similar to the belly scoop on the P51(as well as the MB5 and the Australian Mustang lookalike, but not scoop shaped, but one with an equal amount of area, could be doable.

I'm not sure if the Germans were even aware of the Meredith Effect, even though at the time of the 119m they might've had more than a few Mustangs brought down that they might have studied. I dunno, but if they weren't(and I have yet to learn that they did know of it, if only by dint of studying the Mustand cooling system in toto), wouldn't something like this be useful now, given advancement in materials technology since the War? I'm speaking as as mechanic who has been doing too much thinking. so perhaps I'm sorely mistaken in my assumptions. Still, it might be something worth consideration, 'cause an engine that can dissipate engine waste heat at a higher rater due to higher temp/ambient temp differential.

This is what I get for being the kind of person who thinks a few miles outside the litter pan.

 

[TinyTim63]

Here is one patent showing the cooling system and I know that my uncle's patents from Rolls Royce were licenced to the Germans before WW2 in 1937 period.
Espacenet - Bibliographic data

 

[TinyTim63]

Here is one patent showing the cooling system and I know that my uncle's patents from Rolls Royce were licenced to the Germans before WW2 in 1937 period.
Espacenet - Bibliographic data

Espacenet - Bibliographic data