Online lecture on WW2 engine development

[Zipper730]

So the Germans had less advanced radiators than allied designs?

 

[Deleted member 68059]

So the Germans had less advanced radiators than allied designs?

That was slide #40 and 41.

DId you not manage to log in to watch it in the end?

 

[Peter Gunn]

Calum,

Sorry I wasn't able to attend, was it recorded and if so, perhaps posted on a site somewhere to listen at a later date?

 

[Reluctant Poster]

So the Germans had less advanced radiators than allied designs?

The British, not the allies. The Americans continued to use old fashioned honeycomb construction long after Rolls Royce adopted the much more efficient secondary surface (fin and tube) style.

 

[MiTasol]

And, as Calum showed, the Germans used round tube rolled flat that popped back to round at high pressure

 

[overbeck]

The recording is up:

 

[BiffF15]

That was slide #40 and 41.

DId you not manage to log in to watch it in the end?

Calum,

I finally watched your presentation last night. Very well done! You answered quite a few questions I didn't know I had. I'm most certainly getting your book!

Cheers,
Biff

 

[BiffF15]

Purchased this AM.

 

[Deleted member 68059]

Purchased this AM.

Thank you for investing your hard-earned money. I really appreciate it.

 

[tomo pauk]

D Deleted member 68059 - excellent video, thank you very much. I've learned a lot.

 

[Crimea_River]

Haven't heard any more on the book delivery. Money sent........

 

[Deleted member 68059]

Haven't heard any more on the book delivery. Money sent........

Will be send out around 1st week of November 2020.

 

[tomo pauk]

Money sent

 

[Deleted member 68059]

UPDATE:

Book is going to printing press on Friday 25th Sept 2020.

Printing will take a month, and shipping another week, so would expect pre-ordered
copies to arrive at peoples doorsteps in +6weeks from that date (i.e. 6th Nov 2020)

 

[Crimea_River]

Thanks for the update.

 

[Zipper730]

D Deleted member 68059 ,

So, far I'm about 50-60 minutes in, and it would appear that they didn't seem to generally put as much thought into the design of radiators that were designed sturdy enough to withstand the structural forces imposed by high-pressure cooling systems, and it was leading to cracks in the cooling system, though it seemed that Junkers Jumo was handling the problem better than would Daimler Benz.

Though you note that Messerschmitt seemed the only person who really seemed to fully grasp the problem, however, I remember Heinkel had worked on the idea of a surface evaporative cooling system which did involve considerable pressurization of the coolant (I'm not sure what kind of pressures they used, however).

BTW: I did find the idea of the swirl throttle to be quite interesting -- I thought the USSR was the only nation to have 'em.

 

[Deleted member 68059]

D Deleted member 68059 ,

So, far I'm about 50-60 minutes in, and it would appear that they didn't seem to generally put as much thought into the design of radiators that were designed sturdy enough to withstand the structural forces imposed by high-pressure cooling systems, and it was leading to cracks in the cooling system, though it seemed that Junkers Jumo was handling the problem better than would Daimler Benz.

Though you note that Messerschmitt seemed the only person who really seemed to fully grasp the problem, however, I remember Heinkel had worked on the idea of a surface evaporative cooling system which did involve considerable pressurization of the coolant (I'm not sure what kind of pressures they used, however).

BTW: I did find the idea of the swirl throttle to be quite interesting -- I thought the USSR was the only nation to have 'em.

As far as I have discovered, the swirl throttle was a French invention in radial form, thereafter (since it was published) anyone sensible started their own designs, I think Germany next got one and then Russia, however, I`ve not had nearly as much Russian info as I`d like, so its possible that Russia and Germany were in roughly parallel development.

Its chicken and egg for radiators, if you dont forsee the need for high pressure cooling, you dont develop strong radiators... however it takes a long time to do it, so its something you need to have integrated into your long term gameplan as its not rapidly implimentable.

 

[Zipper730]

As far as I have discovered, the swirl throttle was a French invention in radial form, thereafter (since it was published) anyone sensible started their own designs, I think Germany next got one and then Russia, however, I`ve not had nearly as much Russian info as I`d like, so its possible that Russia and Germany were in roughly parallel development.

Fascinating.

Its chicken and egg for radiators, if you dont forsee the need for high pressure cooling, you dont develop strong radiators... however it takes a long time to do it, so its something you need to have integrated into your long term gameplan as its not rapidly implimentable.

That I understand. I'm just curious how well Heinkel did with the surface evaporative cooling. Do you have any idea how pressurized the coolant was?

 

[Deleted member 68059]

Fascinating.
That I understand. I'm just curious how well Heinkel did with the surface evaporative cooling. Do you have any idea how pressurized the coolant was?

The trouble with evaporative cooling, is that if you pressurise the whole system it stops it from evaporating in the first place, its extremely difficult to allow it to boil-off at some point after the engine, and still maintain a high pressure inside the engine. There are a few things you can do with flow restrictions and so on to get the benefit without letting
the metal temperature in the engine get too high, but its on a knife-edge the whole time, and if the engine power demand suddenly increases, you can get significant
boiling happening inside the cylinder head etc, then you`re done for. There is a lot of interest in evaporative cooling today in automotive engines because of the
very high cooling possible by allowing boiling (i.e phase change) you can get away with a much lower flow rate of coolant which means smaller pumps etc,
but it requires a lot of very clever controls to make it work, which has so far not seen it being adopted in production. Even when it is set up perfectly
the metal temps in the head in some typical studies are 10 degrees higher. Which might not sound much, but if you have a high performance engine,
it might be enough to cause problems - and thats if it works perfectly. I`ve never used such a system, so I only know what I`ve read on it.

Some modern studies in evaporative cooling for engines are:

http://sro.sussex.ac.uk/id/eprint/63582/1/A REVIEW OF EVAPORATIVE COOLING SYSTEM CONCEPTS.pdf
https://people.bath.ac.uk/enscjb/D22903.pdf

 

[MIflyer]

Shell-tube heat exchangers are much easier to build and much, much easier to repair than fin-plate HEXs (like you see in an auto radiator). But shell tube HEX have much lower effectiveness per area than do fin-plate.

You could just about build a shell-tube HEX in your garage using hand tools. But almost no one even tries to repair an auto radiator other than perhaps soldering up a leaky edge.

The F-106 ECS used shell tube. The F-4 ECS uses fin plate. The F-4 has two ECS systems, but the total area of the HEX for the two are no more than that of the F-106, and probably less.

We had a company that had developed a success repair method for shell-tube and had built replacements for Boeing 727 ECS fin-plate HEX. They wanted to build replacement shell -tube HEX for some fighters but we said NO. Jet fighters have a lot less margin in their ECS than do airliners.