Atmospheric engines always overheat?

[JDCollie]

I've been playing career mode, and I've been trying to reach the north pole. However, every time I send an aircraft, its engines start to overheat about 15 minutes into the flight. Turning the engines off and even landing don't seem to have much effect. Is heat not convecting properly, or am I doing something wrong?

(This occurs with both the basic and turbojet airbreathing engines for me)

[sal_vager]

How hot are they getting? They can get very hot before they explode.

[n0xiety]

There must be something wrong with your game atmospheric engines do not overheat just by working at full throttle. For engines to overheat enough to explode you must be going really fast and with an angle that allows the airflow to hit the engine side. Since engines are behind the craft generally the part at the tip or intakes explodes well before engine does.

[JDCollie]

There must be something wrong with your game atmospheric engines do not overheat just by working at full throttle. For engines to overheat enough to explode you must be going really fast and with an angle that allows the airflow to hit the engine side. Since engines are behind the craft generally the part at the tip or intakes explodes well before engine does.

Hmmm, interesting, and good to know.

[cybersol]

Engines do generate internal heat (int flux on thermal debug action menu), and I have seen some overheating from atmospheric engines when I attached them to a low thermal mass part. Attaching them directly to any decent size fuel tank (1-ish ton+) should eliminate the overheating easily though.

[Sharpy]

Eh, my engines do overheat, as designed: when the craft reaches 1200m/s in the middle atmosphere, looking like a huge ball of flames, they surely do overheat a lot.

1. Throttle down. Slow down.

2. Precooler. Attach the engine to it.

3. Make sure they are attached near (in terms of number of parts between) some control surfaces or wings/winglets. These dissipate heat very efficiently.

[n0xiety]

Engine itself isn't overheating tho friction is heating the plane and the ship is heating the engine. Yes the engine generates its own heat but that is hardly a problem. For an engine to overheat enough to explode before the parts at the tip of the plane you would need the tiniest plane you can ever build. Even my 1 seat long range jet doesn't have a problem with its engine while going 1550m/s at 25k+ altitude. Intakes on the other hand are a whole different matter.

[Rocket Ronald]

I encountered the same problem with the basic jet-engine; there is only a certain amount of time or distance it will fly before overheating.

I have tried

- flying at lower throttle: no effect (only slows heating)

- mounting radiators: no effect (only dissipates heat from skin of parts, not internal heat from engine)

- cooling engine nacelle: no effect at all (none that I could notice)

- landing the aircraft, wait and/or fly something else and come back later: engines were as hot as I when left them

What Does help:

Land and put your plane on parking brake, set time-warp to 1000x for just an instant, and all is back to nominal

Im sorry its not a realistic solution, but it works! (version 1.03)

[PPR]

The overheating is a product of atmospheric friction. Once you get over Mach 2.5 (~850 m/s) the parts will start to overheat. When you use the basic jet engine this is not a problem because the engine doesn't have enough power to cause trouble. When you use the Turbo ramjet engine, you will start to see problems because the engines grow more powerful at higher speeds. (There are examples of this in real life: when the MiG-25 exceeded about Mach 2.83 it would tend to run away and overheat.)

Also, pay close attention to the maximum temperature of the parts. Some parts, like batteries and photovoltaic panels have a maximum temperature of 1200K. A Mk1 cockpit can stand 2000K, a Mk2 2500K and a Mk3 2700K. Once you get above Mach 3, things will start to explode unless you have been very careful in your aircraft design. You want parts that have a high maximum heat, especially the root part. You also want to be able to get rid of the heat quickly. Parts that are good for that are wings, engines, radiators and the engine precooler. With the right construction you can get up to a sustained speed of Mach 4.5. I've even managed an air-breathing jet capable of an apoapsis of over 120km.

You can find out more if you read the wiki on the Turbojet.

[cjones]

My jet engines always overheat, no matter what speed or altitude I fly at. I tested by flying at 200m/s at about 1/3 throttle at 7000m, overheating still occurred just slower. Also, the heat never dissipates, even when the engines are off.

If on a space plane, I can get into orbit, do my mission and come back and the engines are always at the same heat level.

Someone was kind enough to find the solution in my particular case: http://forum.kerbalspaceprogram.com/threads/126930-1-0-3-4-Radiators-don-t-pull-heat-from-engines?p=2074097&viewfull=1#post2074097

Edited July 12, 2015 by cjones

[Feradose]

Going faster (to a point) with Whiplash seems to cool the engine off for a bit.

Also since stock aero&thermo overhaul, night flights are more cold because the big round shadow.

Ive never seen an overheat bar with Wheesley and RAPIERs.

[PPR]

If you look in the .cfg file for a part you will find this:

emissiveConstant = 0.95

As I understand it, this is basically a multiplier for how quickly a part gets rid of heat. The higher the number the better. Not every part has this, meaning you need to attach a part that does get rid of the heat, like a wing, engine, or pre-cooler. If you don't the heat gets trapped and builds up until...BOOM!

[Kennosuke.ken]

On 11/07/2015 at 10:27 PM, cjones said:

My jet engines always overheat, no matter what speed or altitude I fly at. I tested by flying at 200m/s at about 1/3 throttle at 7000m, overheating still occurred just slower. Also, the heat never dissipates, even when the engines are off.

If on a space plane, I can get into orbit, do my mission and come back and the engines are always at the same heat level.

Someone was kind enough to find the solution in my particular case: http://forum.kerbalspaceprogram.com/threads/126930-1-0-3-4-Radiators-don-t-pull-heat-from-engines?p=2074097&viewfull=1#post2074097

The heat from the engine does dissipate but it's dissipate REALLY slow. You just have to observe it VERY closely