Swirl throttle effect?

[mack8]

Have watched Mr Douglas's video on the subject, and have been searching/ reading on this forum about this swirl throttle gizmo, but if you bear with me (i can understand the basics but i'm not THAT technically minded!) i'm curious about the following: Mr Douglas says using this device gives 10% extra power at takeoff, and Tomo Pauk for instance says that would give 100-120 PS if used for instance on a DB-605, presumably this applying to any other engine that could have used it like Jumo-211, BMW-801C/D etc? Now Mr Douglas says the device gets progressively open as the rated altitude is reached (when the device is fully open and has no effect anymore).

Looking at the power curves for instance of the DB-605 with variable speed supercharger, one can see the TO power is 1475PS, steadily rises to 1550PS at 2100m, then gradually drops to 1355PS at 5700m rated altitude. My question is, would the swirl throttle increase power only up to 2100m, OR it will have a gradually decreasing effect (as it is progressively open) all the way up to 5700m rated altitude?

In the case of the two speed BMW-801 for instance, would it increase power only up to the 1st SC gear altitude, or it will have an effect up to the 2nd SC gear, in wich case the power curve looking something like the one for Jumo-213?

And lastly, would this device increase power on any engine that does not have it even if already using MW-50 for instance (or C3 boost etc.)? Various Jumo-213 variants used MW-50, and DB-603L/N or 605L fitted with swirl throttles used or were supposed to use MW-50. To give an example, a DB-605AM fitted with a swirl throttle will give more power over it's 1800PS, something like 1900-1950PS?

Thank you.

 

[tomo pauk]

Looking at the power curves for instance of the DB-605 with variable speed supercharger, one can see the TO power is 1475PS, steadily rises to 1550PS at 2100m, then gradually drops to 1355PS at 5700m rated altitude. My question is, would the swirl throttle increase power only up to 2100m, OR it will have a gradually decreasing effect (as it is progressively open) all the way up to 5700m rated altitude?

My take:
At any altitude where the throttle is not fully open, the swirl throttle is of help, since it reduces throttling losses vs. the 'normal' butterfly throttle. On the DB 601/603/605, throttle plate operated by the boost control (on DB 605, at least, there were three throttle plates) was used to reduce the boost delivered by the S/C ('Geblaesedruck') to the boost actually delivered to the cylinders ('Ladedruck') between SL and the rated altitude, so the engine is not over-boosted beyond the allowed value.
Above the rated altitude, 'Geblaesedruck' was equal to the 'Ladedruck' - see here; note that graph is for the ram effect.
The main gain for the DB engines would've been present at the altitudes where there was the greatest difference between the 'Geblaesedruck' and 'Ladedruck' (ie. at the altitudes where the greatest amount throttling is applied) - ie. at really low altitudes (indeed for take-off) and, at least for the Db 605A, at around 4 km (no ram; at ~5km with ram).

In the case of the two speed BMW-801 for instance, would it increase power only up to the 1st SC gear altitude, or it will have an effect up to the 2nd SC gear, in wich case the power curve looking something like the one for Jumo-213?

For the BMW 801, as well as other 2-speed supercharged engines, the effect would've been present in both gears.
For the 3-speed supercharged engines, like the Jumo 213E and F, the effect would've been present for all 3 speeds.

And lastly, would this device increase power on any engine that does not have it even if already using MW-50 for instance (or C3 boost etc.)? Various Jumo-213 variants used MW-50, and DB-603L/N or 605L fitted with swirl throttles used or were supposed to use MW-50. To give an example, a DB-605AM fitted with a swirl throttle will give more power over it's 1800PS, something like 1900-1950PS?

Ideally, we'd want all the bells and whistles - swirl throttle + ADI + hi-oct fuel + 2-stage S/C + intercooling.

Jumo 213 engines already with swirl throttle; when ADI was also used, the gain in power was substantial - see here for 2100 PS for the Sondernotleistung on the 213A (= uses MW50) and 'just' 1780 PS for the Notleisung ( = no MW 50).
Similar gains were with C3-fueled 213A, but without MW50.

See here for 300 PS gain with MW50 on the Jumo 213F.

As for the DB 605AM, yes, I'd say that we'd seen power of above 1900 PS down low if the swirl throttle was used.

 

[Bretoal2]

My take:
At any altitude where the throttle is not fully open, the swirl throttle is of help, since it reduces throttling losses vs. the 'normal' butterfly throttle. On the DB 601/603/605, throttle plate operated by the boost control (on DB 605, at least, there were three throttle plates) was used to reduce the boost delivered by the S/C ('Geblaesedruck') to the boost actually delivered to the cylinders ('Ladedruck') between SL and the rated altitude, so the engine is not over-boosted beyond the allowed value.
Above the rated altitude, 'Geblaesedruck' was equal to the 'Ladedruck' - see here; note that graph is for the ram effect.
The main gain for the DB engines would've been present at the altitudes where there was the greatest difference between the 'Geblaesedruck' and 'Ladedruck' (ie. at the altitudes where the greatest amount throttling is applied) - ie. at really low altitudes (indeed for take-off) and, at least for the Db 605A, at around 4 km (no ram; at ~5km with ram).



For the BMW 801, as well as other 2-speed supercharged engines, the effect would've been present in both gears.
For the 3-speed supercharged engines, like the Jumo 213E and F, the effect would've been present for all 3 speeds.



Ideally, we'd want all the bells and whistles - swirl throttle + ADI + hi-oct fuel + 2-stage S/C + intercooling.

Jumo 213 engines already with swirl throttle; when ADI was also used, the gain in power was substantial - see here for 2100 PS for the Sondernotleistung on the 213A (= uses MW50) and 'just' 1780 PS for the Notleisung ( = no MW 50).
Similar gains were with C3-fueled 213A, but without MW50.

See here for 300 PS gain with MW50 on the Jumo 213F.

As for the DB 605AM, yes, I'd say that we'd seen power of above 1900 PS down low if the swirl throttle was used.

We must see the "gizmo" is very close to supercharger intake and its rotor.

Intake SWIRL gives a variable pitch effect on supercharger rotor and improves its efficiency.
Better efficiency = lower inlet temperature = higher inlet air mass = more power.

 

[tomo pauk]

We must see the "gizmo" is very close to supercharger intake and its rotor.

Intake SWIRL gives a variable pitch effect on supercharger rotor and improves its efficiency.
Better efficiency = lower inlet temperature = higher inlet air mass = more power.

Well put.

For anyone wanting to get into the details of why the swirl throttle was such a beneficial piece, I'd recommend for them to read the translated German report on the "Polikovskiy's device", a.k.a. the Mikulin's swirl throttle.

 

[Bretoal2]

Well put.

For anyone wanting to get into the details of why the swirl throttle was such a beneficial piece, I'd recommend for them to read the translated German report on the "Polikovskiy's device", a.k.a. the Mikulin's swirl throttle.

Polikovskiy device is a simplified (and un-licensed, of course...) copy of Planiol-Szydlowski supercharger...

 

[tomo pauk]

Polikovskiy device is a simplified (and un-licensed, of course...) copy of Planiol-Szydlowski supercharger...

Is it?

 

[Bretoal2]

Is it?

Andre Planiol and Joseph Szydlowski built the first swirl - effect supercharger in 1936.

 

[Shortround6]

Is it?

Andre Planiol and Joseph Szydlowski built the first swirl - effect supercharger in 1936

Depending on the model of the Planiol-Szydlowski supercharger you may have two things going on.

You have the moving vanes, which may not actually block the entry of air like a swirl throttle or at least not as much but will help direct the airflow and you have the up to 3 axial stage compressors in front of the main centrifugal stage compressor. Since there were no stators between the disks of the compressor I am not sure if really was a 3 stage compressor or just a way of getting a long curved entry to the actual compressor disk with the manufacturing technology of the time.

What you could manufacture in 1950 for an impeller may not have been what you could manufacture in 1939 even if you had the idea.

I would also note that the Planiol-Szydlowski supercharger as built, requires the air flow to do around a 90 degree turn after going through the vanes while the Russian supercharger does not. The Russian set up takes the air which is approaching the supercharger (an it is probably from a 90 degree bend in the duct) and introduces a swirl to the airflow.

The P-S supercharger takes air from both sides to feed a plenum chamber, the air goes through the vanes and gets a swirl motion and then does the 90 degree turn into the first of a axial flow turbines/fans.
At least that is my understanding.
I Believe that the Turbomeca company used some of the work of Planiol-Szydlowski is design their early turbo jets.

 

[tomo pauk]

Andre Planiol and Joseph Szydlowski built the first swirl - effect supercharger in 1936.

That is not a proof that Polikovskiy copied something from them.

 

[tomo pauk]

I would also note that the Planiol-Szydlowski supercharger as built, requires the air flow to do around a 90 degree turn after going through the vanes while the Russian supercharger does not. The Russian set up takes the air which is approaching the supercharger (an it is probably from a 90 degree bend in the duct) and introduces a swirl to the airflow.

The P-S supercharger takes air from both sides to feed a plenum chamber, the air goes through the vanes and gets a swirl motion and then does the 90 degree turn into the first of a axial flow turbines/fans.
At least that is my understanding.

Agreed all the way.

 

[Deleted member 68059]

The general principle of using swirl to alter the characteristics of flow, was known and used in general industrial application way back into the 1920`s (nothing to do with engines), its very likely that people had the idea of what to do going back FAR further than this, as its application is extremely obvious to anyone technically trained looking at the famous Euler Turbomachinery equation (Euler died in 1783).

As far as I can see Sydlowski & Planiol were the first people to apply this to an aero engine supercharger for the purposes of an improved boost control method, but in radial blade form. In terms of AXIAL form, I have yet to see anything earlier than the DVL swirl throttle (in testing in Sept 1940, so design would have been underway at least a year before on paper), which must have been developed at approximately the same time as the Mikulin Axial swirl throttle, although not having the Russian papers its impossible to say when they actually started the design on paper. This also goes for Polikovsky stuff.

Other than the Russians, the only people to apply it in WW2 combat were Jumo with the 213.

The axial form is considerably better as the entry into the supercharger is direct and so the peak efficiency will be higher. The radial inflow (Sydlowski) design
is however very useful indeed for making a compact installation.

I dont think any patent/ licensing aspects are very relevant to usage as its obvious from the Euler Equation from 1783, and technically speaking (although these days this rule is bent very heavily) a patent cannot be granted unless the solution is Quote: "non-obvious". These days there is so much money to be made from granting patents (let alone the licensing) that they let you patent nearly anything.

 

[Bretoal2]

The general principle of using swirl to alter the characteristics of flow, was known and used in general industrial application way back into the 1920`s (nothing to do with engines), its very likely that people had the idea of what to do going back FAR further than this, as its application is extremely obvious to anyone technically trained looking at the famous Euler Turbomachinery equation (Euler died in 1783).

As far as I can see Sydlowski & Planiol were the first people to apply this to an aero engine supercharger for the purposes of an improved boost control method, but in radial blade form. In terms of AXIAL form, I have yet to see anything earlier than the DVL swirl throttle (in testing in Sept 1940, so design would have been underway at least a year before on paper), which must have been developed at approximately the same time as the Mikulin Axial swirl throttle, although not having the Russian papers its impossible to say when they actually started the design on paper. This also goes for Polikovsky stuff.

Other than the Russians, the only people to apply it in WW2 combat were Jumo with the 213.

The axial form is considerably better as the entry into the supercharger is direct and so the peak efficiency will be higher. The radial inflow (Sydlowski) design
is however very useful indeed for making a compact installation.

I dont think any patent/ licensing aspects are very relevant to usage as its obvious from the Euler Equation from 1783, and technically speaking (although these days this rule is bent very heavily) a patent cannot be granted unless the solution is Quote: "non-obvious". These days there is so much money to be made from granting patents (let alone the licensing) that they let you patent nearly anything.

Yes. In term of "compact installation", Planiol-Szydlowski had to manage with an existing engine and tried to do not extend its length....

And on the "copying" subject, see Hispano-Suiza 12 Z and KV 107.... Soviets copied all !

 

[tomo pauk]

As far as I can see Sydlowski & Planiol were the first people to apply this to an aero engine supercharger for the purposes of an improved boost control method, but in radial blade form. In terms of AXIAL form, I have yet to see anything earlier than the DVL swirl throttle (in testing in Sept 1940, so design would have been underway at least a year before on paper), which must have been developed at approximately the same time as the Mikulin Axial swirl throttle, although not having the Russian papers its impossible to say when they actually started the design on paper. This also goes for Polikovsky stuff.

At least the manual for Mikulin AM-42 engine ( as well as for the VK-108 and 108) note the swirl throttle as 'Polikovskiy's device', not 'our device' nor 'our swirl throttle'.

And on the "copying" subject, see Hispano-Suiza 12 Z and KV 107.... Soviets copied all !

Is that claim easy to prove?

 

[Bretoal2]

At least the manual for Mikulin AM-42 engine ( as well as for the VK-108 and 108) note the swirl throttle as 'Polikovskiy's device', not 'our device' nor 'our swirl throttle'.



Is that claim easy to prove?

Just open your eyes and look at the dual & differential inlet of the HS 12 Z and the VK 107. Thread here : Klimov VK-107 - help needed

 

[tomo pauk]

Just open your eyes and look at the dual & differential inlet of the HS 12 Z and the VK 107. Thread here : Klimov VK-107 - help needed

Was the 12Z ever able to do 3200 rpm? Even 3000?

 

[Bretoal2]

Was the 12Z ever able to do 3200 rpm? Even 3000?

Certainly not. But the unique system of the dual & differential inlet is identical in principle.... and was never used in any other engine, would it be, or not, in the HS 12Y family.

 

[tomo pauk]

Certainly not. But the unique system of the dual & differential inlet is identical in principle.... and was never used in any other engine, would it be, or not, in the HS 12Y family.

We both know that a working engine - even the imperfect ones, like the 12Z and the VK107 - consisted of many parts, all of whom were required to function very well on their own and in concert one with another for an engine to be service-worthy. Having one item that shares a principle/layout is not a proof that someone "copied all !" on a different engine.

 

[Deleted member 68059]

Certainly not. But the unique system of the dual & differential inlet is identical in principle.... and was never used in any other engine, would it be, or not, in the HS 12Y family.

That has nothing whatsoever to do with a compressor swirl throttle though, so I`m mystified as to its relevance here.

 

[Bretoal2]

That has nothing whatsoever to do with a compressor swirl throttle though, so I`m mystified as to its relevance here.

I only wanted to say that Soviet technology from that period was partly licensed, partly intelligence-copied. Seems to me rather obvious for the PRINCIPLE of swirl throttle and dual & differential inlet... Both from Hispano-Suiza, a french firm who was said to be a "nid de Rouges"....

 

[Deleted member 68059]

I only wanted to say that Soviet technology from that period was partly licensed, partly intelligence-copied. Seems to me rather obvious for the PRINCIPLE of swirl throttle and dual & differential inlet... Both from Hispano-Suiza, a french firm who was said to be a "nid de Rouges"....

It's very difficult to say precisely what was copied and what they did themselves. The axial design is so different that it's a totally new mechanical design meaning that if they copied it they only copied the idea, but as I've stated that's no proof of much in this case as the maths was around for two hundred years and the swirl vanes were in use in general industry at least as far back as 1920 ish. So to get the idea didn't need any input from a foreign engine for this specific item. We don't know is the only accurate statement on this until someone finds papers in Russia. Which, depressingly looks like something none of us will be doing soon