Radial Engine Body does... what? why?

[LethalDose]

As far as I can tell, the radial engine body has no purpose what-so-ever, other than cosmetic appearance. This seems to have been the case since it was introduced in 0.15.

Is anyone aware of the reason that this part is currently in the game or was placed in the game originally? Is this a place holder for something, or is it just a relic of previous patch or idea that has since been ditched? Overall, SQUAD seems good at not leaving old left-overs from previous editions, but the persistence of this part through multiple game versions perplexes me.

Any thoughts or Dev comments re: this little guy I haven't found?

[Geschosskopf]

It adds weight, drag, and a part to the count.

You CAN use it as a piece of structure for aesthetics, putting an intake on 1 end and an engine on the other, but why not use a fuel tank instead?

[DisarmingBaton5]

Probably the only stock part I've never used. It doesn't even look nice IMO

[Tank Buddy]

It looks cool.

But really, some parts were added to KSP without full functionalitly, since the game is in Alpha, so keep that in mind. I'm sure you could copy the part file from the Engine Nacelle so it had functionality.

[Kasuha]

It would be a bit cooler if its intakes were providing some air like the nacelle does.

Apart of that it's mostly cosmetic part, originally probably intended as part which can be radially attached to a wing and serve as a base for jet engine.

[LethalDose]

It adds weight, drag, and a part to the count.

You CAN use it as a piece of structure for aesthetics, putting an intake on 1 end and an engine on the other, but why not use a fuel tank instead?

This is pretty much my thought: why not put something useful in it's place.

It looks cool.

But really, some parts were added to KSP without full functionalitly, since the game is in Alpha, so keep that in mind. I'm sure you could copy the part file from the Engine Nacelle so it had functionality.

Yes, the game is in development, but I was wondering if anyone was aware of comments by the devs that this had a function that has now been dropped, or there was a use for it which has yet to be implemented.

Obviously, it's possible that the devs have a plan for it. The point of this question was if there has ever been any discussion of actual plans for it, and if so, what those plans.

[jBeta]

I made an attempt to use the radial engines in a scenario where I wanted a docking port on the bottom of a central fuel tank. It turned out that just attaching 3 fuel tanks and engines worked better though in that case.

[DeMatt]

It might be intended for use as a pre-cooler, as on the SABRE engine. But right now, no, it's just decorative structure.

[ThinkOutsideTheHangar]

Its purely aesthetic, like the structural fuselage. No practical purpose, other than a space filler, but you can use it for decorating planes.

[Taki117]

if you want it to have purpose take a look at the KSP Interstellar Mod. It adds some interesting things, one of which is engines requiring a precooler, and adding said functionality to said part.

[tavert]

It used to have a somewhat valid application doing the same job as the structural fuselage (adding new radial stacks with 1m attach points) at a slightly lower mass, but more recently added structural panels (or empty fuel tanks thanks to tweakables) serve that purpose even better.

[EatVacuum]

It might be intended for use as a pre-cooler, as on the SABRE engine. But right now, no, it's just decorative structure.

if you want it to have purpose take a look at the KSP Interstellar Mod. It adds some interesting things, one of which is engines requiring a precooler, and adding said functionality to said part.

Actually. KSP Interstellar takes the radial engine body and retitles it as an Intake Precooler, so if you use KSP it now has necessary functionality. Of course, the functionality is necessary because the dev also added some code to make the Rapier and Turbofan engines oveheat at the extreme high speeds as they do in real life, as you can see from the KSPI code snippet below.

@PART[RAPIER]
{
MODULE
{
	name = ModuleSabreHeating
}
}

@PART[turboFanEngine]
{
MODULE
{
	name = ModuleSabreHeating
}		
}

@PART[radialEngineBody]
{
@title = Intake Pre-cooler
@description = A magnificent piece of engineering that pre-cools the air flow from atmospheric engines, preventing overheating at high speeds.
MODULE
{
	name = FNModulePreecooler
}
}

If you do a little reading on the Reaction Engines SABRE engine (the real life prototype that RAPIER is modelled on) and you'll see that while the hybrid rocket/jet engine is innovative, the really big breakthrough they have accomplished is cooling down the intake air. I guess the KSPI dev wanted to inject that element of realism into the game. If that's what your looking for, give it a try, it's an interesting mod. And for anyone who cares, here's some PR about the precooler...

Ultra-Lightweight Heat Exchangers:

These cool the incoming airstream very quickly and effectively, from over 1,000 °C to minus 150 °C in less than 1/100th of a second (six times faster than the blink of an eye). They are extremely lightweight  approximately 100 times lighter than current technology  allowing them to be used for aerospace applications for the first time.

2012 SABRE Pre-cooler Demonstration Facts:

â—¾Over 50 km of heat exchanger tubing for a weight penalty of less than 50kg

â—¾Heat exchanger tube wall thickness less than 30 microns (less than the diameter of a human hair)

◾Incoming airstream to be cooled to -150 °C in less than 20 milliseconds (faster than the blink of an eye)

â—¾No frost formation during low temperature operation

It's kind of counterintuitive but to get a jet engine working at high mach speeds, you have to slow down the intake air... so that you can speed it up again by burning it with fuel to produce thrust. The problem is slowing down the air to a usable speed also heats it up too hot, so now you have to cool it down, and it looks like they have achieved that, for the first time. The alternative is something like a scramjet which is another option that has it's own challenges to overcome. Problem is scramjets don't work at subsonic or even low-supersonic speeds, so even if you could get a scramjet to work at high enough speeds to run you out of the atmosphere at orbital speed and then switch to a closed cycle (i.e. rocket) mode, you'd still need another engine for the lower, slower part of the flight.

And now I've wasted enough of your time. Go fly rockets or spaceplanes!