engine failure

[Yo-Yo]

Oil is part of cooling system, so it affect temperature of whole powerplant, (even a governor and propeller pitch angle if its powered by motor oil are affected but thats not our concern).

 

Oil temperature, quantity and viscosity are all connected, we cannot isolate only one parameter.

 

Powerplant temperature is a sensless matter like average patients temperature in a hospitale. Different parts of a an engine provide different amount of heat flow to the oil.

Oil quantity has no direct effect on the heat sink because oil circulation will be the same.

Anyway, I must say that we do have this effect if the oil quantity is less than a certain amount.

[sam777777]

Powerplant temperature is a sensless matter like average patients temperature in a hospitale. Different parts of a an engine provide different amount of heat flow to the oil.

Oil quantity has no direct effect on the heat sink because oil circulation will be the same.

Anyway, I must say that we do have this effect if the oil quantity is less than a certain amount.

 

Probably referring to EGT or CHT. CHT is the "purer" of the two.

[sobek]

CHT makes sense in an air cooled engine, in a liquid cooled one, not so much, it would be a redundant instrument.

[Yo-Yo]

Probably referring to EGT or CHT. CHT is the "purer" of the two.

 

Engine Gases Temperature? For the piston engine?? Exhaust gases????

 

To be serious, some facts: heat sink to oil is about 1/10 of heat sink to coolant, CHT for air-cooled engines , as sobek wrote, is an analogue of coolant temperature of water-cooled engines, in water-cooled engine there are no means and need to measure any other temperatures than oil and coolant, because the termal condition of the engine is determined primarely by coolant temperature and then - oil temperature. Oil temperature gauge main role is to inform about OIL QUALITIES as a lubrication agent because both too cold and too hot conditions are not optimal for it.

Edited August 21, 2012 by Yo-Yo

[sobek]

Exhaust gases????

 

Exhaust gas temperature, yes, very relevant instrument for piston engines without automatic mixture control. :)

[Ramstein]

almost all my engines failures are actually from the golden BB.... flying over some target and one stinkin piece of lead hits the planes in the perect kill spot... magically,,, and unless you can find the tiny hole... you never actually find out where in the engine it was hit... the engines just poops out...

 

There is not much you can do,,, other than avoiding circumstances where you might get hit by guns... (that's liquid cooled engines in war...)

:doh:

[sobek]

almost all my engines failures are actually from the golden BB....

 

Wait for the next update, you'll have to unlearn a lot of bad habits. ;)

[Yo-Yo]

Exhaust gas temperature, yes, very relevant instrument for piston engines without automatic mixture control. :)

 

Yes, I know the histories how experienced pilots controlled the mixture for cruise looking at exhaust stacks at night. The colour of the hot metal indicated the right lean mixture. But this temperature has no use regarding the whole temperature condition of the engine.

[26-J39]

Yes, I know the histories how experienced pilots controlled the mixture for cruise looking at exhaust stacks at night. The colour of the hot metal indicated the right lean mixture. But this temperature has no use regarding the whole temperature condition of the engine.

 

Are you saying mixture has no/negligible effect on engine temp or " temperature condition of the engine" ?

Lean mixtures can completely destroy an engine, seen it many times.

 

That being said I've never worked on a Merlin and I suspect Yo-Yo might be saying in a round about way that the coolant channels and oil galleries are large enough to overcome any over temp affects of mixtures.

[Yo-Yo]

Are you saying mixture has no/negligible effect on engine temp or " temperature condition of the engine" ?

Lean mixtures can completely destroy an engine, seen it many times.

 

That being said I've never worked on a Merlin and I suspect Yo-Yo might be saying in a round about way that the coolant channels and oil galleries are large enough to overcome any over temp affects of mixtures.

 

No, I never said it. Moreover, mixture effect is used in the engine model - rich mixture lowers the overall heat flow to the engine. The destruction you described is well known but primarely the devastating effect of lean mixture is local overheating of the parts that have relatively low heat conductivity to cooling agent (liquid or air) such as exhaust valves and spark plugs, for example.

Lean mixture that burns slowly changes the pressure timing during the stroke and provoces detonation.

 

Thus, detonation, local overheating and ruined temperature and pressure distribution through stroke are devastating.

 

I love the fact that Bendix-Stromberg always cooks righ mixture so I have not to implement threse factors too... :)

Until we implement enrichment jet clogging in it...

[26-J39]

Ah ok gotcha. :thumbup:

[sam777777]

Yeah, by EGT I meant exhaust gas temperature. It's the gauge I'm used to IRL (I fly cheap planes). I can see how CHT wouldn't be effective in the P51, I still have much to learn regarding the working of this aircraft. I have to get the manual printed soon.

[Yo-Yo]

Yeah, by EGT I meant exhaust gas temperature. It's the gauge I'm used to IRL (I fly cheap planes). I can see how CHT wouldn't be effective in the P51, I still have much to learn regarding the working of this aircraft. I have to get the manual printed soon.

 

I always think that it's vital for gas turbine (jet, turboprop, turboshaft) engines, not piston. In piston engines exhaust gas temp can not indicate how much heat flows to the engine body. It's a thermodynamics cycle parametre and it will be very possible that at cruise power rate this temperature is higher than at MAX.

[kevins]

It really is incredible that we have these hi fidelity aircraft models to fly. When I die, I'm leaving all my money to ED!

[sam777777]

It really is incredible that we have these hi fidelity aircraft models to fly. When I die, I'm leaving all my money to ED!

 

Regarding Yoyo's post: "Yep, aha, I know some of these words." :smartass:

 

 

I know exactly what you mean, coming from ROF and Il2 (ROF doesn't even simulate engine heat due to mixture settings) DCS is just incredible.

[cichlidfan]

It really is incredible that we have these hi fidelity aircraft models to fly. When I die, I'm leaving all my money to ED!

 

You could give them half now, as a gesture of good faith!! :P