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Engine damage

FWIW
I've worked a little more on the gauge (see .zip).
Current one allows inclusion of a climb setting with extended time-to-fail.
If two settings are the same, the less severe will be used (e.g. Climb RPM=TO RPM=2700 RPM -> 60 min allowed at 2700 RPM)

Just drop the .xml file into the gauges/RealEngine or panel/RealEngine folder.

Add/change the entry in panel.cfg to

[Window Titles]
...
WindowYY=RealEngine

[WindowYY]
position=3
size_mm=200,180
gauge00=RealEngine!RealEngine - MP RPM Limitations v04, 0,1

Note you have to pull up the gauge (Menu View-Control Panel-RealEngine) before it becomes active.

All variables are adjustable either by clickspots or in the .xml file.

Also see the manual for v3:
http://www.flightsim.com/file.php?cm=SEARCH1&fsec=73&fname=realenginev03.zip

I'm currently working on modules for
- Flap/gear failure due to exceeding Vf/Vl speeds
- Plug fouling due to extended idling
- Engine running rough/damage if mixture is leaned too much

Gunter
 
Glad to see you working on such accessories! please not for most aircraft that max gear speeds are promulgated on (1) aerodynamic loads for the gear doors (2) for small planes available hyd pressure to engage the downlocks. In the case of the 747, gear extended limit is M.82, however M1.0 has been exceeded in the "field" without damage to the gear itself.....

Fs tends to have the aircraft or component explode if a "limit" is exceeded. The 747 has a certified cruise limit of M.92, but I know that it has been cruised across the pacific at M.96 and flight tested to M.998. "Limits" apply over a whole range and assure certain load and upset parameters can be met. Execeeding these limits reduce the available size of the envelope.

RPM: FS tends to emphasize this in the evaluation of CHT. RPM is hard on an engine and with corresponding MP builds CHT and can cause lubrication failure and resultant connecting rod/piston "problems". Without high or low MP, high RPM is merely inefficcent if not required. Some engines such as the R 2800 are more tollerant of over MP than over RPM, such as in a dive. Lots of ways to puke an engine.

Cheers: T
 
I do like the rough idle and also the over lean parameters. One of the weak spots in FS engine parameters is CHT, which seems to be affected primarally by RPM, a little less by airspeed and somewhat by cowl flap position. To see where this is problematic, reduce power at a set RPM and CHT will climb due to the reduced airflow. Take it at an extreme position to the CHT limit, plugging along at low speed and low power.... Then firewall it and CHT will drop as speed increases. A gauge that would be useful would tie EGT more closely with RPM to generate a more realistic figure.

Cheers: T.
 
Hi Tom,
thanks for your input!
I can need all the help I can get to understand under what conditions and how the components on the planes are failing, and what effects that has! No experience with real planes here. Input highly appreciated!

Currently I'm taking a very pragmatic approach - if the POH says don't do it, the engine will fail, or something else unwelcome, will happen if you do... :engel016: ... with very simple logic.

So I'm far from creating a parallel aircraft model with Otto cycle and all...

However, that project is on slow burner for the time being. With the MacRobertson race going on that is taking up all my available limited sim time :icon_lol:. Like there's this more or less nice competion by kids time, darling time, job time, friends time, do stuff time, ect...
Also, I had rushed development before the event as I hoped to use the modules in the race. But Warwick Carter's Gee Bee I'm flying now already has such great damage modeling, so no need there.

I'll get back to it after MacRobertson is over.
The flap/gear module is almost alpha, but I think I'll need some advice when I have something ready.
Maybe it's completely unrealistic, and I have added some sound effects with Doug Dawson's sound gauge, but have no idea if the sounds are even remotely similar to what one would hear (if anything!) in a real case. (also love A2A accusim's approach of assymmetric flap failure, but don't know whether I should implement their idea).
The others modules are still in design stage.

I'd love do discuss this more when MacRobertson is over and I can devote some more time!

Thanks.

Gunter
 
A pretty good way of modelling minor onset of engine difficulties could be through sound and (new idea) minor vibration modeled through the head movement possibilities in FSX. for those deaf and blind, further possibilities exist.....

Cheers; T
 
teson1 said:
But Warwick Carter's Gee Bee I'm flying now already has such great damage modeling, so no need there.
Click to expand...

Gee thanks compared to your stuff the GeeBee is very basic.... :)

Ok for you all knowing ones...think this is on topic? :)
P&W R-1340-AN-1 single speed supercharger,what MP would I expect at sea level with the throttle to the wall,Ive read reports from current pilots about their take off procedures and notice it was said a few times that they used the max permissibly MP of 36 for take off but the throttle wasnt all the way to the wall.This got me thinking I can use the Accel engine damage to supplement some xml coding.Yeah I working on a Texan (prob the SNJ as carrier ops are fun ) Im concentrating more on the systems this time round...if FSX will let me..... curse you Msoft you won the first 2 rounds but I will not go quietly into the night :D
Thanks
Wozza
 
Most of the various super/turbo charged GA type engines that I have flown have been like that. Fairly simple controls, a max listed MP, which however does allow you to keep pushing the throttle up (if required) till some critical altitude (perhaps 4000' or so) is reached where the max throttle movement will match the max permissible MP. Max climb MP would be available to a somewhat higher altitude.

The single most dangerous factor that can lead to quick and fatal engine destruction for large piston engines is detonation. Not always obvious as to what might cause detonation except high MP is the main ingredient. However high octane fuel, and use of ADI (water methanol) injection delay the onset. The temperature of the mixture prior to entering the cylinders is a factor. Intercoolers (and their proper use) as well as low outside temperatures help this out. High outside temps, bad fuel etc. are contributing factors.

Cheers: T
 
Thanks Tom
At the mo I have the super charger set up to give me an full throttle MP of 36 at around 5.5k ft which then gives me a MP about 42ish at sea level,with a detonation_onset of 36.0 this will mean a long wait for complete engine damage with the built in accel damage model but will do as a start.I so wish we could plug into the default failure system via xml code,some of the effects are cool :)
Thanks
Wozza
 
Indeed if it were possible to "supercharge" the detonation effect. Detonation can tear up an engine in even the short minute or so of a takeoff. The DC6 flight engineers have copious instrumentation which helps them a lot in engine managment. During the 1944 fighter conference the use of detonation detectors in fighters was discussed. The USN viewpoint was that such "gadgets" were prone to failure and error and might cause more problems via distraction.

One of the problems is that a particular episode might not blow a jug off, but cause problems later. Even cracking from over cooling from a rapid low throttle descent might not show up immediatly.

Failure is often a result of a multitude of previous sins....

Nice plane! T
 
Wozza said:
Gee thanks compared to your stuff the GeeBee is very basic.... :)
Click to expand...
Very kind of you, but completely off...
At least wait till I've delivered. :d
I really like your Gee Bee; I'll pull this up also after the race. Real fun to buzz around in it!
Gunter
 
LOL. No fear, not forgot.
Just still having too much fun with the London-Melbourne trip. Never mind the race part is over. Takes up all the available time.
(And progressed a little with the code nevertheless.)
 
Another "on the radar" bump..

I've been fascinated with this type of gauge(s) for years.. but never got around to working on it. I intended to have something ready for my last model (the Bonanza P35).

ANYway.. I'll throw some ideas in..

Has cumulative CUMULATIVE damage been pondered ? As in not just for that session, but so that abuse adds up flight after flight. We already know that FSX stores engine time. I believe it's a simple text file somewhere in the user's documents folders. You can see how it works on aircraft whose tachometers also display hours... which is most of them. This engine failure gauge could read/write to a similar text file keeping track of long-term, cumulative wear.

And in addition to MP and RPM.. throw in CHT abuse ?
 
Hi, I'm still here...
and on it. :wiggle:

I warned you in the beginning you'd have to give me a few months... :icon_lol:

With the RTW race over, I can focus more. And I think I'll also just leave my Bee Gee a little more time hangared in Java, before continuing on to Melbourne to finally finish that London-Melbourne *cough* race...

Actually, good news is I've progressed a lot on the modules in the mean time, most just need some more final testing.
I plan to release for beta testing soon (within the next few weeks... but don't hold your breath).

Modules finished and just needing final testing are:
- Engine damage - impact of MP, RPM, power, mixture, CHT, oil temperature
- Leaning - engine running rough with overrich or overlean mixture
- Spark plug fouling
- Gear and flaps failure due to overspeed

But don't get overexcited... you'll find that implementation and effects are pretty crude.
Really, these modules just have something _bad_ (not necesarily something realistic!) happen if limitations or recommendations of the POH are disregarded.
Goal is simply to enforce limitations are respected to the letter, as one would probably in real life.
Just wait till it's released.

Brett, CHT as a source, and indication, of engine damage was high on my wish list as well. Actually there's a simple module generating engine failure if CHT limitation is exceeded. However, from the testing I've done it seems that CHT (impact of power settings, cowl flaps, speed, temperature, ground operations, mixture ect on CHT) is poorly modeled in FS9. So the whole effect is kind of useless as CHT does not behave realistically. To have a halfway realistic damage effect due to CHT, I believe CHT has to be controlled from outside of FS. I have a lead on how to do that, but that's currently _way_ over my head... maybe later...

No cumulative wear. Not possible with XML AFAIK, and IMO the damage model is not fine enough to get something realistic out of it long term.

But thanks for bumping. A little reminder from time to time does help. :icon_lol:

Gunter
 
Yup

CHT is about worthless in FS, we tried to tie engine damage in the FSX DC2 to it without much sucess as it is almost wholy dependent on RPM.....

Cheers: T
 
Yes, I noticed in FS9 and in FSX (except for A2A's AccuSim), cylinder head temperature is directly linked to engine RPM. There must be a way around it, seems to me the 1% group that remade the flight models for CFS2 and CFS3 aircraft were able to implement cylinder head temperature based on other factors. I remember cooking the engine of the F4U-1A while trying to land. I don't know how they did it or if it was really accurate, but it was frustrating trying to keep that engine cool.
 
I believe for a single aircraft it's pretty easy to implement.
Just don't display A:RECIP ENG CYLINDER HEAD TEMPERATURE by the CHT gauge, but an L: variable.
This L: variable can be anything from FS CHT + an offset to a separate model of the physical effects that may affect CHT (power, cooling, damage ect ...).
I believe this is how it's done in Wozza's Gee Bee (btw, I'm an expert in cooking that engine...).
Of course this only works if implemented by the acft designer, or if the CHT gauge can be edited to display the L: variable.
 
In one plane I was involved in we linked invisible cowl flaps to the mixture value, such that the stoichemetric value closed the cowl flaps fully and either side of peak opened them, to allow manual leaning of the mixture by watching CHT. However we wer still stuck with the direct RPM link, such that even on a low powered descent it was possible to overheat the engine which triggered a damage scenario.

I think the FS guys stuck with a simple fixed pitch model of developing CHT, using RPM/airspeed/cowl flap position to generate a value. A fairly useless set of assumptions for a constant speed prop.

Cheers: T
 
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