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#1591
09-27-2010, 05:07 PM
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So far with all the mods I've tried, everyone seems determined to dampen or completely mute the propellor sound, which I personally like very much. In one of the mods I took a soundeditor and had to amplify it with 400% to get it to the original level.
And I can't really find evidence these shouldn't be used. Every time I hear a turboprop passing by, first I hear the props and later, much fainter, the turbines. Something completely different: Has anyone mentioned mixture control and the associated behaviour yet? I love the upcoming multiple engine prop/power/radiator controls but accurate mixture control would add so much more. Currently the strange effect of reaching 5 km of altitude and suddenly having a drop in power and a trail of black smoke, is far from reality. Also, probably written before, a number of craft aren't perfectly modeled on the supercharger/turbocharger thing. For example, the P47 has an extra turbocharger control lever and RPM gauge for the turbo. Both the F4U and P47 have additional intercooler flaps and dito control. Although the F4U has automatic intercooler capability, the pilot manual warns of situations where manual operation is mandatory. During testing with the F4U, the Carb Heat warning light (temperature of the air inside the intake manifold) never turns on. Even if at sea level and 60 inches of manifold pressure, I switch from neutral blower(1) to low(2) or high(3), pressure never exceeds 60 inches which seems a bit odd: AFAIK a carburetted supercharged engine does not use an automatic pressure-relief valve. I guess that engine temperature is modeled purely by measuring the oil (or coolant) temperature while in real life, detonation was/is a serious threat to engine health, often melting holes through the top of the pistons, even if coolant or oil temperatures are well within operating standards. AFAIK the only planes that have damage modeled through something different than overspeed, battle damage or overheat are planes with MW50 and even that is not done correctly. In real life one chooses a pressure setting with the throttle, say 1.8 ATA, and before that switches on the MW50 accordingly. In the sim you switch on the MW50 and suddenly the ATA increases. What in real life happens is that the amount of air that is compressed increases, but the pressure stays the same, only due to the charge cooling effect of the water and thus the lowered temperature of the air between supercharger and cylinders. It's even worse: take a K4 and start the engine with throttle at 0%. Watch the manifold pressure. Now switch on the MW50. You'll see the increase in pressure while engine RPM stays the same. This is wrong. It would be better if we have a HUD warning telling us the temperature in the intake manifold is too high, so the pilot can lower throttle OR lower supercharger stage OR open intercooler flaps OR engage water/MW50/fuel injection, or all of them. Cylinder head temperature (CHT) is a different story, as this is controlled by manifold pressure, engine RPM, IAS, mixture setting and cowl flaps a well as atmospheric condition like humidity or rain. This can be measured roughly with coolant/oil temperature, but not always. Fast increases in CHT can happen if the engine RPM is too high, IAS is too low, the mixture is too lean and temperature in the intake manifold is not even at max, while the heat capacity of the oil/coolant system takes time to catch up with the true condition in the cylinder head(s) and produces an incorrect reading, depending on the placement of the temperature sensor. If we want even more realism we would have to remember notes for each plane separately, which includes the max amount of manifold pressure, engine RPM and mixture/blower/intercooler setting for every given situation, like shown in various movies on YouTube. The single switch "Complex Engine Management" may not be enough as a lot of people would want a mix of settings or wouldn't want to remember notes for the odd type they fly occasionally. The wiki on turbochargers: "Pilots must make smooth, slow throttle adjustments to avoid overshooting their target manifold pressure. The fuel mixture must often be adjusted far on the rich side of the peak exhaust gas temperature to avoid overheating the turbine when running at high power settings. In systems using a manually-operated wastegate, the pilot must be careful not to exceed the turbocharger's maximum RPM. " I understand that proper turbo/supercharger/intercooler/mixture control for each plane is a lot of work and maybe even beyond the capability of the IL2 engine. But it can be nice to have. For example on full realism dogfights with the F4U against lower performance planes like the KI-61 with some DB interpretation of the Kommandogerät, this can even out the odds if a pilot isn't proficient with engine management. At least a http://en.wikipedia.org/wiki/Engine_knocking warning or high intake manifold temperature warning coupled with gradually increasing engine damage would be really nice to have. I'm not sure how to embed them so I post the links instead. Ohw, this one is funny! This one explains in more detail the operation and control of the turbo in the P47: And more on YT, of course  So far my plea for increasing the realism on engine management, as an option for the freaks
Last edited by Azimech; 09-27-2010 at 05:39 PM. |
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#1592
09-27-2010, 06:14 PM
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That's exactly the kind of things i'ld like to see modelled and the reason is that it gives us more ways to screw up...more chances of a mistake means more variety in battle damage or more time spent looking inside the cockpit to prevent that damage, which will result in more succesful bounces, just like it used to be in reality
 However, i believe that it's beyond the capabilities of the IL-2 engine or the time needed to do it is too much. Just the amount of controls that need to be mapped would be about a dozen (increase/decrease for each control) and then, not every plane has every kind of control. Plus, not every virtual pilot has a HOTAS with 30 separate command combinations and since IL-2 doesn't support mouse clickable controls, it would make for an extra 10-15 keybindings on an already crowded keymap configuration. Not to mention that some things are highly individual between different aircraft, for example mixture. Some have full manual control, some have fully automatic and some have semi-automatic (like the US birds where you choose between 2-3 presets:cut-off,auto lean,auto rich, full rich). In order for this to be modelled in a fully realistic manner, the mixture increase/decrease commands would have to be coded for each aircraft individually. For example, in a plane with manual mixture control an increase command would be moving the mixture lever gradually, but in a US fighter it would need to move only between the 3-4 discrete steps, and so on. It's one of the reasons i'm eagerly awaiting the arrival of SoW however. |
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#1593
09-28-2010, 12:27 PM
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I see the problems involved so I only advocate the following:
Mixture only becomes a problem when a plane reaches critical altitude, since almost all flyables have a supercharger or turbocharger. 1. Correction of the MW50 problem. 2. Higher resolution mixture control. 3. The adding of engine knocking/detonation/whateveryoucallit. This can be done quite easily, every plane has a maximum allowable manifold pressure, beyond that a sound sample could be added, together with a slow decrease in engine power, say 1% per minute for a slight boost over the red line, to 10% p/m loss of power for let's say 20 inches above the red. And a warning on the HUD. This is where the water injection/MW50 comes in, where instead of calculating complex matter IL2 never had to worry about like intake manifold temperature, switching on these systems virtually just lowers the manifold pressure by substracting a predefined value, but not for the pilot who still sees the original value on the gauge. Once the tanks holding the MW50 or water are empty, the predefined value is added again and engine knocking commences. That's pretty easy, compared with implementing radio navigation Since most planes do not have these systems, other planes can have a small bit of this effect by increasing the mixture/Erhöhte Notleistung, essentially extra cooling the charge before it enters the cylinders, at the cost of higher fuel consumption. That is why I would like to have mixture control with a better resolution, seen on the HUD as percentages above or below "normal" (in technical terms: http://en.wikipedia.org/wiki/Stoichi...f_common_fuels ) These solutions only work until critical altitude is reached and overboosting values cannot be reached anymore. Above that rich mixture or Erhöhte Notleistung become a burden quite quickly, still cooling a bit but lowering performance steadily with altitude. This is also why running with high manifold pressure, a too lean mixture again leads to engine knocking, since the cooling effect of the vaporization of the fuel is less. |
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#1594
09-28-2010, 02:24 PM
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That's actually a solution that could work, never thought of that.
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#1595
09-28-2010, 06:30 PM
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I once had a Citroën DS 21 Pallas semi-automatic 1968, running on LPG. The engine is a 2.1 liter 4 cylinder. I asked too much of that engine, so one day I started to lose power at high speed. Looking in the mirror I saw big plumes of blue smoke appearing, and extra intermittent power drops started to appear. After that I lost cylinder number 2. Examination proved the ignition timing was wrong, I burned a hole in the top of that piston. Those intermittent power drops were the result of engine oil being pushed out of the oilpan and into the intake manifold through the breather, at some moments choking the engine. Coolant temperature was always OK. Even on 3 cylinders the car was quite quick though, and a joy to drive. Even if the engine sounded a bit rough.
This is not comparable with super/turbocharged aircraft engines, car engines have their oil vapors fed back to the engine by law, burning them with the fuel/air mix. Since almost all aircraft engines use dry-sump lubrication, there isn't much oil to lose, except the oil mist in the crankcase that will be pushed past the other pistons due to the supercharged pressure in the intake manifold: the flow passes the intake valve and goes through the hole in the piston, into the crankcase. The engines that spray a jet of oil against the bottom of the piston for additional cooling will lose oil, through the piston hole, at a disturbing rate. The risk of explosions in the crankcase increases dramatically because of the stoichiometric mix of fuel and air in case of a carburetted engine. In case of fuel injection, which happened right into the combustion chamber after closing of the intake valve, the risk of explosion is negligible. Other forms of damage that can appear from engine knocking: *Shattered ceramic isolators on the spark plugs/ Melted spark plugs. Since every engine has two spark plugs per cylinder, this will lead to only a slight decrease in power unless both fail, that's a lot of unburned fuel in the exhaust manifold. P47/P38/B17/B24 hate that, can lead to explosions in the exhaust manifold or turbocharger in extreme cases. *Holes in the cylinder head. In case of a water cooled engine this will lead to excessive loss of oil due to supercharger pressure blowing past the intake valve and through the hole, under the camshaft cover. Will probably produce a lot of oil on the windscreen. In case of a carburetted engine: explosions through the crankcase breather can produce engine fire. Explosions under the camshaft cover may warp or dislocate the camshaft cover, may lead to engine fire and rapid loss of oil, in case of inverted V12's the scavenging pump will not return the oil to the oil tank, worsening the problem. Sometimes the explosions rupture hoses between engine and oil tank: instant loss of oil pressure OR the scavenging pump leaks the oil into engine bay instead of refilling the oil tank. Carburetted radials will blow huge amounts of explosive mixture in the engine bay and the spark plugs will ignite it, engine fire unless enough airflow past the cylinders. Fuel injected radials will less easily catch fire and less severe due to injection when the piston is already half past it's compression stroke and the intake valve is already closed. *Damaged bearings of the piston rod (clunking sound until the rod or piston breaks). *Damaged bearings of the crankshaft (again clunking sound, shaft may break in two or engine block may burst, even explode). *Damage to the valves/ valve seats. Will lead to backfires, loss of compression and possibly engine fire. Some of these symptoms are comparable with running too long with high CHT or prolonged over-revving. IL2 only drops power, plays a sample and ultimately stops the engine. In real life, engine fires were a big and common problem. IL2 doesn't model engine fire caused by abuse by the pilot. In case you have a hole in your piston or cylinder head and don't want a burning or exploding engine: lower manifold pressure so it's under ambient air pressure, let the engine suck for it, fresh air from outside will flush the crankcase. And lean the mixture. If you're flying a multiple engined plane: cut off fuel and feather the prop. Something else to consider: High manifold pressure combined with low engine RPM increases the risk of engine knock. Another reason why running with too much prop pitch, apart from the high torque, is terrible for your engine. Last edited by Azimech; 09-29-2010 at 10:41 PM. |
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#1596
09-30-2010, 02:48 PM
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These suggestions made by other people I'd like to include in my wish list:
http://forum.1cpublishing.eu/showpos...postcount=1292 http://forum.1cpublishing.eu/showpos...postcount=1170 http://forum.1cpublishing.eu/showpos...postcount=1244 And of course, AI engine overheating. Which is already done in some form but I can't link to that since it's on a mod-forum. Send a private message. |
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#1597
10-01-2010, 09:17 AM
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I'm really liking what you're thinking Azimech. I only wonder if the Il-2 engine can handle those things - it's a little hard to predict sometimes. It can model radar, but not the speed of sound...
Switching gears, I've got a rather unusual request: So, we're all aware of the "UFOs" that are part of the game. Now before I go further, let me say that I support the idea of including them in order to test the limits of the FM. However, we can agree that these planes are a little "out there". For instance, dare I say it, the Lerche, which never made it past the sketch-on-a-napkin stage of development. Oleg said something along the lines that if the Germans used their most powerful piston engine, it wouldn't get off the ground, and so his team modeled it with more powerful engines. I agree with that, but at this point it climbs faster than a Me-163. However, the plane can still lift off the ground with a little less than 50% power. So, why not pork the engines a bit so that they develop the equivalent of 60% power or so? To test this, I flew a QMB, scrambling against 4 Yak-3s. I used this power setting as my absolute upper limit, and I still rose fairly quickly. But after leveling out, I realized my speed was not much better than any normal prop-plane, and my maneuverability wasn't phenomenal - I actually had to work for a kill. It's harder to conserve energy, and what you lose will not return to you so quickly. The fight becomes more interesting, and losing even one engine will make it impossible to land the recommended way. All in all, it gives this fantasy plane more plausible behavior - and makes it a little more fun. What do you guys think? *ducks and hides |
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#1598
10-02-2010, 10:09 AM
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I think the engine can't model engine damage they way it happens in real life. I think it can model engine damage as if it were battle damage using a variable counter for the percentage the maximum manifold pressure is being exceeded and the time being done so. This would simplify things a lot.
The problem with engine knock is that the "pinging" sound can be heard from the engine of a car, it cannot be heard inside an aircraft. The planes with a CHT gauge can have a clue, because engine knock increases CHT sharply, which leads to more engine knock and at the end pre-ignition, which destroys the engine within seconds. During engine knock the engine starts to sound increasingly rough, adapting the sound engine to incorporate that, is a challenge and probably will not be done. So the overheating message combined with the manifold pressure should give the pilot it's clues what is happening, and that should be enough (unless a HUD warning is an option). I also understand now that adjusting mixture to prevent these problems is a complex task as well, it can prevent engine knock but can also increase the risk. Probably beyond the scope of what is possible (and probably will meet a lot of resistance from our community), not everyone is interested in engines as I am. So TD, what do you think? As an optional switch I mean. Has this already been done in some form or would it be nice to have this included in the future? |
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#1600
11-01-2010, 06:36 PM
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Quote:
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Linear Mode
