Spit Mk9 Post 3.006 Update

[unreasonable]

I have an additional question for the engineers: why would the "boiling coolant" be emerging from the radiators in the first place?  They are a closed system, apart from the relief valve, of whatever type it was: was the Spitfire relief valve inside the radiator? Was there on one each side?  If not this must mean that the radiator has been so stressed that it has sprung a leak - can that be right? 

 

On the header tank - can the filler cap also function as a relief valve?

[PainGod85]

1 minute ago, ZachariasX said:

Ha, thanks! That is the one on the header tank then!

  Reveal hidden contents

 

Also found this:

 

They installed several "safety devices". Must be likewise in the Spit.

 

 

But only the pop off valve on the reservoir tank.

 

Also, manual temperature limits for th P-51's Merlins were lower than the Spitfire's. Might that be because the Mustang's cooling system was rated for a lower pressure?

 

http://www.avialogs.com/index.php/en/aircraft/usa/northamericanaviation/p-51mustang/nzap-2025h-pn-pilots-notes-for-mustang-p51d.html

 

121 °C for the P-51D, well within the expected internal pressure reserve on a system rated for 5 bar at altitude.

1 minute ago, unreasonable said:

I have an additional question for the engineers: why would the "boiling coolant" be emerging from the radiators in the first place?  They are a closed system, apart from the relief valve, of whatever type it was: was the Spitfire relief valve inside the radiator? Was there on one each side?  If not this must mean that the radiator has been so stressed that it has sprung a leak - can that be right? 

 

On the header tank - can the filler cap also function as a relief valve?

 

They would not. Relief valves are basically an engineer's way of telling the system "If you HAVE to spring a leak, spring it here". They are the system's predetermined breaking point, barring battle damage.

 

No, the filler cap on at least the P-51 had a Schrader valve to prepressurize the system, functionally identical to what you would find on, say, a bicycle tire. This can only ever work one way.

[=EXPEND=13SchwarzeHand]

28 minutes ago, PainGod85 said:

think you're missing a verb there. And I have no idea who or what An P. is supposed to be.

 

No, no verb missing. You are still not making any sense.

An P. Is the guy providing info about the FM of Il2 and his post is the subject of the thread you are rambling in. You should start reading his stuff ??

Edited October 1, 2018 by =EXPEND=SchwarzeDreizehn

[PainGod85]

23 hours ago, unreasonable said:

@PainGod85 I wondered about that, but hesitant to opine lacking an engineering background.

 

This is not on the Spitfire but the P-51: presumably somewhat related, but I will leave that to others to determine, and mentions pressure of up to 50lbs/sq inch (4.5 bars relative to vacuum) more or less in line with your 124 C estimate. 

 

https://www.aircorpsaviation.com/mark-on-maintenance-p-51-header-tanks/

 

And just to connect this value with manual limitations, the P-51's maximum permissible coolant temperature under any circumstances was 121 °C.

Just now, =EXPEND=SchwarzeDreizehn said:

 

No, no verb missing. You are still not making any sense.

An P. Is the guy providing info about the FM of Il2 and his post is the subject of the thread you are rambling in. You should start reading his stuff ??

 

Nah, you just lack a basic understanding of physics in regards to pressurized systems. And a verb.

 

Also, there is no such user registered on this forum.

[=EXPEND=13SchwarzeHand]

4 minutes ago, PainGod85 said:

Nah, you just lack a basic understanding of physics in regards to pressurized systems. And a ver

 

Yes certainly but obviously in your side ?

[PainGod85]

Just now, =EXPEND=SchwarzeDreizehn said:

 

Yes certainly but obviously in your side ?

 

Do you even have a background in natural sciences? No? Then assume you're wrong.

[ZachariasX]

7 minutes ago, PainGod85 said:

Also, there is no such user registered on this forum.

He's talking of @AnPetrovich

[=EXPEND=13SchwarzeHand]

Hahaha, I’ll let you continue making a fool of yourself, since you obviously even fail to understand the difference between a relief or blow off valve and a pop off valve. Have fun in your lab mate!

[ZachariasX]

You can see thow it is done for the intercooler coolant system in the MK.IX here:

 

It is basically the same for the engine coolant circuit. I'll post it if I find a good drawing.

 

Edit, here the Spit cooling, for your convenience:

EDIT2: @unreasonable is absolutely right, this is the 109 cooling system. Pasting that quickly over a cup uf coffe made mix those up. Two nice rads as in the Mk.IX. Darn. But nice to see that in the 109 it works absolutely the same. It did dtart out with a RollsRoyce after all    I find a correct plan.

You have 2 overpressure valves (k) that ventilate to the right and the left(h)  in the Mk.IX in case you're overdoing it.

 

Edited October 1, 2018 by ZachariasX

[unreasonable]

The relief valve (of whatever kind) is on the header tank:  so why is there white stuff coming out of both of my Spitfire IX's radiators?

[Talon_]

27 minutes ago, unreasonable said:

I have an additional question for the engineers: why would the "boiling coolant" be emerging from the radiators in the first place?  They are a closed system, apart from the relief valve, of whatever type it was: was the Spitfire relief valve inside the radiator? Was there on one each side?  If not this must mean that the radiator has been so stressed that it has sprung a leak - can that be right? 

 

On the header tank - can the filler cap also function as a relief valve?

 

The coolant should emerge from the relief valve.

 

The Spitfire's implementation is all kinds of messed up.

 

 

[PainGod85]

1 minute ago, ZachariasX said:

You can see thow it is done for the intercooler coolant system in the MK.IX here:

 

It is basically the same for the engine coolant circuit. I'll post it if I find a good drawing.

 

Yeah, and the second relief valve on the P-51 cooling system overview is on the reservoir tank for the closed supercharger coolant loop. Guess they really were using just one pop off valve on the engine cooling system after all. Color me unsurprised.

[ZachariasX]

3 minutes ago, unreasonable said:

Spitfire IX's radiators?

It shouldn't. It only produces steam there, if someone helped you with that.

[unreasonable]

3 minutes ago, ZachariasX said:

It shouldn't. It only produces steam there, if someone helped you with that.

 

I am still not clear on why there should be steam emitting from the radiator if the relief valve, which is not near the radiator, works correctly:  is the suggestion that some seal or pipe in the radiator has actually broken?  

[PainGod85]

Just now, unreasonable said:

 

I am still not clear on why there should be steam emitting from the radiator if the relief valve, which is not near the radiator, works correctly:  is the suggestion that some seal or pipe in the radiator has actually broken?  

 

He was being facetious. Someone helping with that means someone shot your radiator full of holes.

[=EXPEND=13SchwarzeHand]

Im guessing the graphical implementation is wrong. Should be a bug report then.

Edited October 1, 2018 by =EXPEND=SchwarzeDreizehn

[ZachariasX]

8 minutes ago, unreasonable said:

I am still not clear on why there should be steam emitting from the radiator

If you overheat your engine (in a real Spit IX), then you have vapors eberging behind the prop, as shown on the plan (h). It is made there on purpose by intelligent people for less intelligent people (that can't see squat down there in the darkness with these hopleless dials) to see when they are cooking their engine and ACT!

 

These vapor trails should also be a little more toned down, I wouldn't even expect them to be trailing the aircraft. If an amout of coolant wuld be ejected to form a "chemtrail", you'd have an aircooled engine very, very soon.

 

12 minutes ago, =EXPEND=SchwarzeDreizehn said:

but a pop off valve popping at the max permissible temperature for 5 minutes

Pop off valves don't have timers. They ONLY sense pressure differentials.

 

6 minutes ago, =EXPEND=SchwarzeDreizehn said:

Should be a bug report then.

Yes. Another one to the radiators of my fav ride.

Edited October 1, 2018 by ZachariasX

[unreasonable]

3 minutes ago, PainGod85 said:

 

He was being facetious. Someone helping with that means someone shot your radiator full of holes.

 

Ah I see - German language humour translated into English.... thanks.

 

So who is going to explain to @AnPetrovich that his team has made a total hash of the Spitfires?  (Both types - since although we have been talking about the Mk IX  I bet that the same is true for the Mk V - it certainly displays rather similar symptoms.  Come to think of it, does this "steam out of radiator"  stuff happen for other aircraft too? )

[Talon_]

Bug report here: 

 

 

Try to stay on topic though guys. There are two bugs here - 1. Wrong steam location, 2. Premature overheat and coolant loss due to nonfunctioning radiator. My report is for bug 2. Somebody else needs to report bug 1.

Edited October 1, 2018 by Talon_

[=EXPEND=13SchwarzeHand]

22 minutes ago, ZachariasX said:

Pop off valves don't have timers. They ONLY sense pressure differentials

Really???

I never even said anything against that, actually I made exactly your point a couple of times before. Please argue with someone whose opinion differs on anything you have said so far ?

My point is, that if a pop off valve pops at a max permissible temperature, which is permitted for 5 minutes you loose all your coolant so the instruction of only using it for 5 minutes would be a nice joke among pilots. Which is what douchegod was saying. A pop off valve should be going off ABOVE max permissible temp. Is it that hard to understand?

Max permissible temp has NOTHING to do with the setting for the valve!!!

 

Think I spelled everything correct now

Edited October 1, 2018 by =EXPEND=SchwarzeDreizehn

[-=PHX=-SuperEtendard]

But we dont know whats actually wrong with it... Maybe the rads were supposed to open only at 120ºC but the valve system doesnt hold the pressure correctly (should do it until service ceiling conditions or slighlty above) or the coolant has too high vapor pressure modelled for the pressure/temperature conditions...

 

 

Edited October 1, 2018 by -=PHX=-SuperEtendard

[unreasonable]

Since @ZachariasX has the drawings that show the Spitfire relief valves, I nominate him to put in a "steam in wrong place" bug report.  As for the other issue, whatever the mistake in the modelling we can only really ask the team to take another look, which I hope Talon_'s bug report would initiate.

 

 

59 minutes ago, ZachariasX said:

You can see thow it is done for the intercooler coolant system in the MK.IX here:

 

It is basically the same for the engine coolant circuit. I'll post it if I find a good drawing.

 

Edit, here the Spit cooling, for your convenience:

You have 2 overpressure valves (k) that ventilate to the right and the left(h)  in the Mk.IX in case you're overdoing it.

 

 

Just a thought: I wonder if you know that the bottom drawing is also posted as a Bf 109 E cooling system, here: (look at Technical reference/Cooling)

 

http://109lair.hobbyvista.com/index1024.htm

Edited October 1, 2018 by unreasonable

[Talon_]

1 hour ago, -=PHX=-SuperEtendard said:

But we dont know whats actually wrong with it... Maybe the rads were supposed to open only at 120ºC but the valve system doesnt hold the pressure correctly (should do it until service ceiling conditions or slighlty above) or the coolant has too high vapor pressure modelled for the pressure/temperature conditions...

 

 

 

FYI mate 115degs ?

[ZachariasX]

3 hours ago, unreasonable said:

Since @ZachariasX has the drawings that show the Spitfire relief valves, I nominate him to put in a "steam in wrong place" bug report.  As for the other issue, whatever the mistake in the modelling we can only really ask the team to take another look, which I hope Talon_'s bug report would initiate.

 

 

 

Just a thought: I wonder if you know that the bottom drawing is also posted as a Bf 109 E cooling system, here: (look at Technical reference/Cooling)

 

http://109lair.hobbyvista.com/index1024.htm

Got me there, corrected that. Have to put some order in my link library again. But I'll find a correct plan.

 

Edit: as a first, I just have the docs on how A2A simulations implemented that on their Spit Mk.I/II:

It is not that different on the Mk.IX, as the valves are most likely postioned in accordance to how they are placed in the Mustangs Packard.

 

But I hope it is clear to anyone that an overheating engine is not "fuming" at the radiator when overheating. It would only do so if overpressure would bust the radiatior.

Edited October 1, 2018 by ZachariasX

[BlitzPig_EL]

Sir I do know how cooling systems work in the real world.  I work on antique automobiles as my profession.  With a calibrated spring, which is how a radiator cap, or a pop off valve works, it will only relieve pressure when the pressure exceeds the amount that the device is set for.

 

You are treating a sealed cooling system as it of were the envelope of a blimp filled with helium.

Edited October 1, 2018 by BlitzPig_EL

[ZachariasX]

44 minutes ago, BlitzPig_EL said:

With a calibrated spring, which is how a radiator cap, or a pop off valve works, it will only relieve pressure when the pressure exceeds the amount that the device is set for.

The problem here is that the calibrated spring only senses the pressure differential between inside the tubings and outside, whereas the boiling point of the juice inside the rads is dependent on absolute pressure. And this absolute pressure indeed varies with different altitudes. In cars, that outside pressure varies much less. But it will considerably do so if you were to cross he Andes in your car. Water is cooking only at 100° centigrades if you start out with 1 atm ambient pressure. To get that, you will have less margin for steam pressure.

 

at sea level, 1 atm steam pressure will get you water to 120° centigrades. at 10'000 meters it will go only to 106° centigrades. After that pressure diferential is > 1 atm pressure and the valve will open.

 

 

 

[453=Thornley]

Hi Gents,

 

I'm really confused by all this.

 

In an open system, like a saucepan, water boils at 100 °C at sea level (1atm), 71 °C on Mt Everest (.33 atm) and instantly boils in space (0 Atm).

 

but, in a closed system, like a pressure cooker, with 1 atm, water boils at 100 °C irrespective of if it's at sea level, on Mt Everest or in space... That's why you can drive your car (which ALL have closed systems) over the Andes. Top Gear actually do this in one of their specials.

 

So what the dev's are saying is that aircraft like the Spitfire used an Open system??? That seems amazingly weird to me as ww2 cars, trucks and motorbikes all used closed systems.

[ZachariasX]

1 hour ago, Bloodsplatter said:

but, in a closed system, like a pressure cooker, with 1 atm, water boils at 100 °C irrespective of if it's at sea level, on Mt Everest or in space...

The point of pressure cooker is that you will boil your potatoe at 120 degrees centigrades (using 1 atm steam pressure) and not at 100 degrees.

 

In the closed pressure cooker (if you closed it at sea level with water and hopefully the potatoe inside) there will be 1 atm already.

 

Now, it is irrelevant whether you 1) first start to heat it or 2) if you bring it up to the mout Everest first.

 

1) Any heating up to the boiling point doesn‘t produce steam pressure, so you canalways heat your cooker to that point. Should you heat it to 1 atm steam pressure and bring it to the mountain then, you will see that as soon as you move to lower pressures, your valve openes and releases steam pressure, maintaining 1 atm pressure differential. If it didn‘t do that, you‘d have 1.75 atm pressure differential at the top of the mountain and that cooker would burst.

 

2) will also produce about 0.75 atm pressure inside the cooker (heavily dependent on the weather on the mountain), this means you only have 0.25 atm pressure left to max out the pressure differential, reaching a steam presdure of 1.25 atm and unly 106 deg centigrades.

 

You understand now why it is good to have a pressurized cooling system with a high pressure tolerance. The higher my total pressure, the smaller the effect of losing athmospheric pressure. If I can have 4 atm of steam pressure, that will be still 3 atm in space with no air. Also remember, the shift in water heat vs. steam pressure is not linear. This should also hint to why Glycol was chosen along with water (or instead of) as coolant in aircraft.  The kind of liquid also affects the boiling point.

 

On Top Gear, they could drive that high as normal operating temperatures of an engine should be well below temperature limits encountered at altitude. But there will be a clear tendency to overheat in thin air. At least in turbocharged cars, where performance is not droping with altitude. But the cars they used there (these were the British ones right?) a Jag XJS will hardly produce even 100 hp at altitude. You need less cooling for that.

[453=Thornley]

Thanks ZachariasX

[KingstonDE]

Hi gents,

 

as i dont know mutch about the Spitfire, i have a question to you:

 

In the 109/190 handboock you can read that as more altitude you make, the boilingpoint of the water collant from 100 degrees, went down to around 59 -69 degrees

shown on the  display at max high. So at say 10.000m the max temp that was allowed was 59 - 69 degrees on the display. So should not drop the boilingpoint

for the watercoolant in the spit also go down, or you use different coolant mix?

 

On the other side i think maby they only forgot to check the techchat and edit it to the new system. What happens when you see that your coolant start to boil

and you reduce power till it stops. Is than normal flying without engine damage possible?

 

regards

 

Little_D

Edited October 3, 2018 by 1./JG2_Little_D

[unreasonable]

@1./JG2_Little_D  The coolant mixture might have been a factor, but the allowable maximum pressure in the system is also relevant. 

 

When the pressure in the system reaches a certain limit, a relief valve opens letting out steam until the pressure is no longer high enough to hold the valve open.  The altitude, strictly speaking, is irrelevant to the boiling point: all that matters is the pressure in the system.  As you climb the external pressure drops, so the difference in pressure in and out of the system gets greater for a given coolant temperature making the relief valve open at lower coolant temperatures.  The question is what level of pressurization was the Spitfire system able to maintain. 

 

I do not actually know that from a document, but given the maximum temperatures for the Spitfire (and other Merlin powered aircraft) were considerably higher than for the German fighters, it seems certain that they could operate at considerably higher pressures.  Hence we would like to know where the devs got their information.  Currently the 109s can climb to altitude at 30 minute ratings and never emit steam using automatic radiators  - even though they are well over the altitude dependent temperature limits on their gauges.  Meanwhile the Spitfire cannot. Something seems very wrong, quite possibly in both the Spitfire and 109 modeling. 

[KingstonDE]

Hi unreasonable,

 

thx for the info. I also read that the coolling power of the air that goes thru the radiators at high alt is less, because the air is thinner. I read in the forum that the spit have some problems with the radiators on automatic in BoX. So looks like there are more problems on the spit. And yes hopefully they fix all the little easter eggs in this sim. Like a P-39 shadow when you are flying a Fw190 at low alt .

 

regards

 

Little_D

 

 

Edited October 3, 2018 by 1./JG2_Little_D

[CountZero]

The problem is that automatic control of ots radiators dont work, its fully closed, and it doesent open when it starts to overheat like it did before patch, so you have to open radiators manualy and thats always 100% or nothing, and you cant close them or get them to auto after that. So you can only fly it at 100% open rads or brake engine up high.

[Barnacles]

15 minutes ago, 1./JG2_Little_D said:

 I also read that the coolling power of the air that goes thru the radiators at high alt is less, because the air is thinner.

 

True the air is thinner, but true airspeed is higher for constant power with increasing altitude (although indicated air speed falls slightly). As a pressurised radiator system maintains the specific heat capacity of the water as altitude rises, and air temperature decreases with increasing altitude, pressurised radiator systems are more effective at higher altitudes.

[unreasonable]

23 minutes ago, 77.CountZero said:

The problem is that automatic control of ots radiators dont work, its fully closed, and it doesent open when it starts to overheat like it did before patch, so you have to open radiators manualy and thats always 100% or nothing, and you cant close them or get them to auto after that. So you can only fly it at 100% open rads or brake engine up high.

 

Fly the Mk.IX at low altitude and high power and you will see that the radiators open when the temperatures go above 115 C, just like they did before, just as the manual says.    The problem is that the coolant is boiling out of the radiators at altitude at far too low a temperature as though the cooling system is  inadequately pressurized.  So the radiators, even closed, are doing an adequate job of cooling: it is the boiling point that seems to be wrong. 

 

Edit - also bear in mind that the Spitfire radiators are never "fully closed" in the sense of not working - they provide a fair measure of effective cooling even when closed.

 

Edited October 3, 2018 by unreasonable

[Guest deleted@50488]

Are all of these rather important observation being forwarded to the developers ?

[unreasonable]

Talon_   posted a bug report about this topic so one assumes that someone on the team will eventually read it......

[Guest deleted@50488]

Oh, thx, didn't notice it unreasonable.

[JtD]

I've only been reading up a little on the radiator relief valves fitted in various aircraft. The relief valve in the Spitfire was mentioned to relief itself at about 0.25at overpressure. Which might be enough for a glycol mix to reach the referenced water temperature limits. I also had a quick look at my Hurricane documents, and there the relief valve limit is also 0.25at, but followed by quite a bit of extra info which implies it's not all that simple. Before a bug report goes out, it would be nice to know the details of the Spitfire V and IX.

 

The point of relief valves is not so much to not damage the radiators, it's more about preventing the water from becoming hot enough to damage the engine. In this sense, time limits coming with temperature limits might also refer to losses of (pressurized) coolants.

[-=PHX=-SuperEtendard]

49 minutes ago, JtD said:

time limits coming with temperature limits might also refer to losses of (pressurized) coolants.

I dont know... For example at 10000 meters the Spit with the Merlin 70 starts to lose coolant even with the 2850 RPM 1 hour setting, and this at its top speed in level flight. Flying at continuous is the only viable setting up there. There has to be something wrong with the coolant release model

Edited October 3, 2018 by -=PHX=-SuperEtendard