Is it better to close air intakes?

[Jaeleth]

1 hour ago, fourfa said:

Disagree - even with the default Hard settings, it's likely that you will have the tech tree completely filled long before finishing upgrading the facilities.  And increasing financial pressure with difficulty settings pushes you into 100% recoverable craft earlier, not later.

Well... As I said. It has been a long time, so be it then. By the way, action groups should be allowed from the beginning, anyway, it makes sense that to build a large craft you need a large VAB, but it makes no sense at all not to be able to switch on or off two engines at the same time, I can do that in real life with little effort, and I certainly do not have a VAB

Edited September 12, 2016 by Jaeleth

[Jaeleth]

21 hours ago, Sharpy said:

There are some airplanes with these built in.

AFAIK, a few VTOL close the intakes that are close to the ground, leaving the 'roof' ones open; Harrier being a prime example. That's to prevent sucking dust and other crap inside - but at these speeds, the aerodynamics loss is negligible.

 

Ah, VTOL, ok, of course, good exemple.

[Jaeleth]

14 hours ago, Alshain said:

It's not called a "simulator".  So....? Yeah Gameplay above realism as I said.

If it's not a simulator it sure is fooling much people... Lol...

It's more a simulator than a simple game, since it "models" reality, that's what simulator do, it might not be as precise as, say, MS flight simulator for the flight model but it is better than, say, Berkeley Orbiter (which is a SIMULATOR) at the flight model, the reentry and at a par in orbital mechanics... And besides, I have flown real simulators and they looked and felt worse than MS flight sim so...

 

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Why would you assume a game has to have all that?  Not all games have lasers and empires.  This is a tycoon style game.  Hint: RollerCoaster Tycoon isn't 

 No it's not.  You might learn the basics, but there is a lot it doesn't teach.

Of course there is a lot that doesn't teaches! No simulator teaches everything. You can't learn to fly a plane by flying MS flight sim, but it does help to grasp the concepts and you can learn to fly instruments almost exclusively in MS flight sim.

Besides, space flight, unlike atmosphere flight, is maths and calculations, it is IFR taken to an extreme, so to speak, therefore there is actually much more resemblance from KSP's orbital mechanics to real life orbital mechanics than MS flight sim control sensitivity to a real aircraft control sensitivity...

And one thing that this is NOT is a Tycoon Style game, absolutely not! Time is not a significant variable (which would have to, in a tycoon game) money is not the objective (major fail for a tycoon game) merely the means, and you can even play it without any money involved (tech mode, sandbox)  and way, way, way before you "complete" the game (colonized every planet), you already have your "empire" maxed out (full installations, full tech). 

This is a simulator with a fun exploration and buildup side to it, which makes it, also, a game... With realistic overhaul mods you turn it almost into a pure simulator.

The tweakable option should not only exist, as it should expand!

 

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Incorrect or not, it's what KSP is.  Don't like it?  Orbiter is a simulator.  I highly recommend it if you want a simulator.

Orbiter does not simulates atmospheric flight as well as KSP, particularly reentry, the last time I checked, anyway, which was a long time ago, but then again, I don't think they have been evolving it much anyway.

Atmosphere subsonic flight model is also better simulated in KSP. I don't think I can, as far as I remind it, stall spin the crafts in orbiter, I can in KSP, so, KSP is more of a simulator than Orbiter... Ms Flight sim has a better flight model but then again, that one is a pure atmospheric flight sim. Ok, I can't either stall spin the crafts in KSP as I can in real aircraft but at least I can... Somehow...

And surprisingly, I can even use KSP to teach flight students what happens if they load the aircraft unproperly, displacing the Datum (CoM) beyond allowed range, lol. In a simple and crude way, yes, but it does the job. It... Simulates reality...

 

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Wheels are being fixed in 1.2.  I'm not sure what justification you are using for assuming people are more patient for a unique simulator than they are for a unique game like KSP.

Because, as a simulator, KSP is unique, and fun. No other space flight simulators around, and orbiter lacks many realistic features and stopped development ages ago, as far as I can tell. While KSP has a thriving community and is under constant improvement.

KSP's uniqueness also derives from the fact that teaches space flight basics with a fun gaming approach to it. But it only does so because it emulates space flight in a realistic manner (as realistic as you can get on a home PC), if it looses that advantage and concentrates solely on the "fun" side, and I mentioned the wheels problems for this particular reason, it will fail in the long run. You see, there are lots of terrific space games out there, incredible atmosphere, multiplayers, empire building, incredible landscapes... These games appeal to "space fans", where do they loose to KSP? They aren't realistic. Hard core space fans will prefer KSP over them for this reason...

There are excellent racing games out there, race car simulators, stunning graphics you have to look close to discern it is CGI, is KSP rover skidding competing with these? "Stealing" race fans from those games to this one?  Nahhhh... But none of those games simulate the thrill of moving a rover, slowly and carefully, 1 million miles away from Earth... That's where KSP wins.

 

There are amazing Tycoon games... Etc... Etc... And the list goes on... KSP triumphs in it's corner... Simulating space flight, reentries, atmospheric flight in alien atmospheres, mixed with exploration and building crafts (which can also have some learning simulation potential) and resources, for added fun, and standing out from the crowd by doing it in the most realistic manner possible, giving the notion to users that they could really be there, 1 million miles from Earth, reentering in an alien atmosphere with a space plane, going where others fear to tread. Not competing with them in their fields of choice...

 

And... If this was supposed to be a Tycoon style game, Squad would've have tried to get some endorsement from the wall street exchange or something. Who did they get the endorsement from?... NASA... ESA... Well, that pretty much closes the discussion on the simulator thing uh?

 

 

 

Edited September 13, 2016 by Jaeleth

[Sharpy]

15 hours ago, Jaeleth said:

Well... That's an acceptable explanation. So, I will rephrase... They should add it back whenever possible, together with more damage to parts exposed to shockwave in reentry and not coated in ablative material.

 

What for?

It doesn't improve the gameplay. The new model made them totally redundant, and very few people would want it.

It doesn't improve realism. No real airplane closes intakes like that, no actual spaceplanes with air-breathing engines exist, and these airplanes that do close intakes at all, do it for completely different reasons and with quite opposite effects (drag grows instead of dropping.)

It might improve theoretical realism - something that might be done in the future to circumvent problems we foresee but haven't encountered in real life yet. And once we have a working spaceplane prototype and experimental data, it might appear it was actually a horrible idea, and needs to be solved in an entirely different way (turbine blade AoA changeable? Air diverted to alternate outlets? Plane needing to go belly-first anyway, the front-facing intakes never exposed to supersonic flow, the whole problem nonexistent?)

The KSP's politics relative to this class of features is: Write a goddamned mod that does that if you like. This thing will not be stock, because it doesn't make the game more enjoyable, and its realism is highly dubious.

 

Edited September 13, 2016 by Sharpy

[Jaeleth]

4 hours ago, Sharpy said:

It doesn't improve realism. No real airplane closes intakes like that, no actual spaceplanes with air-breathing engines exist, and these airplanes that do close intakes at all, do it for completely different reasons and with quite opposite effects (drag grows instead of dropping.)

It might improve theoretical realism - something that might be done in the future to circumvent problems we foresee but haven't encountered in real life yet. And once we have a working spaceplane prototype and experimental data, it might appear it was actually a horrible idea, and needs to be solved in an entirely different way (turbine blade AoA changeable? Air diverted to alternate outlets? Plane needing to go belly-first anyway, the front-facing intakes never exposed to supersonic flow, the whole problem nonexistent?)

The KSP's politics relative to this class of features is: Write a goddamned mod that does that if you like. This thing will not be 

 

 

No airplane closes intakes like that... Might be true... If I knew what "like that" meant... Since there was no visual display in the game of the intake closing, it is, therefore, assumed that it is a "theoretical, unforseen" closure, which will have to be done, one way or the other, on future re-entering space planes, as I mentioned before. So, we have either 2 approaches:

1. Close the intakes in whatever way, in which case you have to have a function "close intakes" and then imagine how they are closed as you wish to imagine. (Changing the AoA would not protect them from damage, those blades are really fragile). One practical way, yet crude, would be to manually attach an ablative cone, while in orbit, over them. That would solve bpth damage and drag issues on final powerless glide.

 

OR

 

2. Place the intakes protected from the airflow (and we know that neither many ksp builders do this neither the software deals the correct amount of damage to them even when the SSTO in plunging headfirst into Kerbin at 2000m/s or so... As you know, with stock Kerbol System, no thermal shields and no "belly first" are even required for survivable reentry from LKO so the craft can indeed go head first with the turbines getting it all the way.

 

If something can't be implemented in KSP because it is not yet fully implemented and tested in the real world we would have to scrap the nuclear engines... We can always make educated guesses on near future tech...

 

 

Edited September 13, 2016 by Jaeleth

[Sharpy]

 

19 minutes ago, Jaeleth said:

No airplane closes intakes like that... Might be true... If I knew what "like that" meant...
 

Mid-flight, not on or above the runway.

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So, we have either 2 approaches:

We have far more. I can think of a couple. E.g. a passive bypass/limiting system that diverts excess airflow out of the engine's path.

Also - whatever the system will be, it will almost certainly be either passive or automatic. No toggle in the cockpit.

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As you know, with stock Kerbol System, no thermal shields and no "belly first" are even required for survivable reentry from LKO so the craft can indeed go head first with the turbines getting it all the way.

Did you play KSP past 1.0.x at all?

Spaceplane going head first into atmosphere? The turbines are the least of your concern.

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If something can't be implemented in KSP because it is not yet fully implemented and tested in the real world we would have to scrap the nuclear engines... We can always make educated guesses on near future tech...

There were working prototypes. It was never sent into space for political/safety reasons.

Any prototypes of air-breathing spaceplanes out there?

And we can make educated guesses on near future tech, and implement them too. Not in stock though.

[Jaeleth]

16 hours ago, Sharpy said:

 

Mid-flight, not on or above the runway.

by "like that" I meant KSP did not implement a visual depiction on how it is closing the intakes, so you have to imagine they just, somehow, close... Internal cone? External cone? Imaginary Force field? Doesn't matters... They are closed, theoretically reducing drag, now it's left to the player's imagination how they did that...

 

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We have far more. I can think of a couple. E.g. a passive bypass/limiting system that diverts excess airflow out of the engine's path.

What I mentioned are broad categories, your solution falls within my second category (protect them from airflow). Only two: cover them, with a physical cover, or make air not get close to them, the infinite solutions you may find fall either in one or the other category.

 

 

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Also - whatever the system will be, it will almost certainly be either passive or automatic. No toggle in the cockpit.

Maybe... But I know of a very few pilots who wouldn't demand to have a manual override ;)... Virgin galactic's Spaceship changes wing configuration manually... To all it's troubles... And virtues...

 

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Did you play KSP past 1.0.x at all?

Spaceplane going head first into atmosphere? The turbines are the least of your concern.

I play since early 0.9

Neither the turbines nor the entire ship is of any concearn... Do you want me to post a video of me doing that? Yes... It takes a lot more distance to break, but I can always use spoilers, but nothing explodes, nothing burns, in Kerbin of course, in Eve I have to be extremely carefull...

I usually plunge in at the famous 41 degree AoA, sideways, and then switch to the other side, but only for roleplay, if I want to go have a snack and leave the damn thing plunge head on the only thing I have to be carefull with is with some  hard "lithobreaking" if I don't finish my snack before it hits the ground...

I play with stock game, default flight model, and a few "workflow" mods (MJ, KER,  ship's manifest, and the like) that do not interfere in flight performance or materials resistance) I have my career game in 1.0.4 and I play sandbox in the latest version for ship design in stock and another game with maximum realism mods for extra challenge, and fun  (until I can migrate my career rovers to 1.1.3)

 

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There were working prototypes. It was never sent into space for political/safety reasons.

Any prototypes of air-breathing spaceplanes out there?

And we can make educated guesses on near future tech, and implement them too. Not in stock though.

The russians say they will test one (nuclear engine) in 2018.

If they test, the others will test too. Honestly... It's a bit "ackward" to complain about a few ounces of radioactive material orbiting Earth for incredible scientific benefit when nuclear bombers carry, quite often, a far greater amount in warheads around the globe and nuclear vessels carry a lot of it, active, in their reactors in every sea of the world.

Edited September 14, 2016 by Jaeleth

[Sharpy]

5 minutes ago, Jaeleth said:

by "like that" I meant KSP did not implement a visual depiction on how it is closing the intakes, so you have to imagine they just, somehow, close... Internal cone? External cone? Imaginary Force field? Doesn't matters... They are closed, theoretically reducing drag, now it's left to the player's imagination how they did that...

No intakes ever close reducing the drag. That was purely an artistic license by KSP authors with entirely zero bearing on real life and aviation science.

 

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What I mentioned are broad categories, your solution falls within my second category (protect them from airflow). Only two: cover them, with a physical cover, or make air not get close to them, the infinite solutions you may find fall either in one or the other category.
 

Third: let air pass through them causing no harm.

Also, other attainable goals from your categories:

- aerodynamics such that speed growth reduces volume of air entering (extra shield that allows more air in with laminar flow on lower speeds, makes the shock cone miss the intake when supersonic)

- dynamic system that regulates air intake per demand.

 

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Maybe... But I know of a very few pilots who wouldn't demand to have a manual override

Likely. But that override would be hardly ever used, especially in a dynamic system where the intake isn't a simple toggle but actual regulator, manual override would be heavily detrimental to machine performance.

And it's definitely not an option players of KSP need. Just as player's imagination can tell how the intake is closed physically, it can provide the automatic activation.

 

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I play since early 0.9

Neither the turbines nor the entire ship is of any concearn... Do you want me to post a video of me doing that? Yes... It takes a lot more distance to break, but I can always use spoilers, but nothing explodes, nothing burns, in Kerbin of course, in Eve I have to be extremely carefull...

*shrug* I made a "spaceplane" early in the career. Vertical launch, no air-breathers, vestigal wings for gliding to a landing, MK1 cockpit, airbrakes.

Airbrakes overheat massively. They will be blown off if not closed. And with them closed, the cockpit overheats.

What did I do wrong?

[Jaeleth]

5 minutes ago, Sharpy said:

No intakes ever close reducing the drag. That was purely an artistic license by KSP authors with entirely zero bearing on real life and aviation science.

Yes, As I mentioned before no aircraft do this in the real world, this is a speculation.

 

5 minutes ago, Sharpy said:

Third: let air pass through them causing no harm.

Can't do... Hypersonic air (do not forget reentry is at around mach 29) will destroy them even if you find a way to "feather" them, that's the term, at least for propellers, nothing like this was ever done with turbine blades. And the blades aren't the only thing you have to be concerned about in a turbine engine, get a jet engine schematic on the web and see what's in there behind them...

 

5 minutes ago, Sharpy said:

Also, other attainable goals from your categories:

- aerodynamics such that speed growth reduces volume of air entering (extra shield that allows more air in with laminar flow on lower speeds, makes the shock cone miss the intake when supersonic)

- dynamic system that regulates air intake per demand.

yep, but first it must survive reentry, these questions are mainly for restarting turbine after reentry if that is what they plan anyway, probably the turbine on reentry is just dead weight and the ssto will make a powerless glide to runway, like the shuttle.

 

5 minutes ago, Sharpy said:

Likely. But that override would be hardly ever used, especially in a dynamic system where the intake isn't a simple toggle but actual regulator, manual override would be heavily detrimental to machine performance.

And it's definitely not an option players of KSP need. Just as player's imagination can tell how the intake is closed physically, it can provide the automatic activation.

Well... Mechjeb can do almost all the flying for you but... Is that fun?

 

5 minutes ago, Sharpy said:

*shrug* I made a "spaceplane" early in the career. Vertical launch, no air-breathers, vestigal wings for gliding to a landing, MK1 cockpit, airbrakes.

Airbrakes overheat massively. They will be blown off if not closed. And with them closed, the cockpit overheats.

What did I do wrong?

There was one particular, and brief, period of time when that happened... But then squad did change something and it happened no more, unless you tweak the reentry "deadliness" in game settings. 

 

Just done a test in the 20 minutes between these posts.

KSP 1.1.3, full stock, only KER installed to get temperature readings (I have some difficulty in saving videos on this machine). You can go and replicate it now, of you like, it's a simple ship and fast to perform the test:

 

Here are the results:

the vessel is a mk2 cockpit, mk2 drone core, mk2 to 1.25m adapter long, inverted for extra sleekness and a terrier at the end, 2 astronauts. 4 A.I.R.B.R.A.K.E.S mounted around the adapter. A really simple "bullet" with airbrakes...

kerbin orbit

ap 200km, pe 49km, airbrakes deployed

Table of results:

SPEED        ALTITUDE        CRITICAL TEMP. MOST HEATED PART (explodes at 100%)

2400m/s      70km                

2442m/s       60km                38%

2407m/s       50km                59%

2074m/s       40km                 75%

1500m/s        30km                81%

1000m/s        20km               53%

and cooling down until it hit the ocean...

it fell like a rock, head first, at a point I lost energy (i forgot to add batteries)  so it started spinning slowly and wobbling a bit around prograde axis, because i was moving at warp 4 to save time, just reducing warp at checkpoints to read the values, It still had plenty of fuel so it made airbrake worse, if it had less fuel, probably, wouldn't even get to 81% critical heat.

no explosions, no damage... The temp markers didn't even reach the red color, only a deep orange.

 

 

 

 

 

 

 

[Sharpy]

25 minutes ago, Jaeleth said:

Can't do... Hypersonic air (do not forget reentry is at around mach 29) will destroy them even if you find a way to "feather" them, that's the term, at least for propellers, nothing like this was ever done with turbine blades. And the blades aren't the only thing you have to be concerned about in a turbine engine, get a jet engine schematic on the web and see what's in there behind them...

That's an engineering challenge. Maybe make the turbines retractable, leaving the whole duct open.

Or maybe forfeit trubojet engines altogether; use SRB fuel to get to ramjet/scramjet speeds and go bladeless. Turbojets won't gain you much speed anyway, and they ARE heavier.

Again, an engineering challenge. Personally, I think taking a turbojet to the orbit at all is a poor idea. And they absolutely aren't the only air-breathers out there.

 

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Well... Mechjeb can do almost all the flying for you but... Is that fun?

The matter of balance between the game doing everything for you, and need to micromanage each least significant detail. This is entirely a matter of personal tastes, but in my personal opinion closing intakes definitely steps into micromanagement area.

 

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Here are the results:

the vessel is a mk2 cockpit, mk2 drone core, mk2 to 1.25m adapter long

Ah, happy happy joy joy. MK2 was way out of my reach at that time. Do this with MK1 parts. Standard (tip) cockpit, crew cabin, two or three fuel fuselages, Swivel or Terrier.

[Jaeleth]

3 hours ago, Sharpy said:

 

Ah, happy happy joy joy. MK2 was way out of my reach at that time. Do this with MK1 parts. Standard (tip) cockpit, crew cabin, two or three fuel fuselages, Swivel or Terrier.

Ah, the Mk1 does takes less heat. And the 2 or 3 fuselages won't help either, you see, the more weight coming down, relative to drag, the longer it takes to break, the longer it takes, the higher speed it will reach the lower and denser layers of the atmosphere.

i mimicked (sort of) your setup and used an mk1 with 1 astronaut and 1 FL-T800 full of fuel.

first time, head first, exploded at around 30km, critical part: the mk1, ap100km, pe49km

i tried lower pe, it helps breaking faster at the expense of more instantaneous heat but reduces heat buildup (time), That's the way they do it in the real world with capsules (not shuttle). Still blew up. I think the heat buildup issue has yet to be improved in the game

then I tried going tail first, terrier took the heat. And survived... probably due to more drag, more speed bleeding before lower layers since terrier as same tolerance to heat than mk1 cockpit (skin)... It's one of those game things...

still, airbrakes survived the punishment, all the times, all the way. Probably you had few airbrakes coupled with low drag of ship and high weight.

 

well, bear in mind that this is kerbin, not earth, reentry speeds are 3.5 times  lower and so it is acceptable that lots of gear survives reentry even without shielding, some should take damage, yes, but probably not complete stuctural integrity loss.

 

if you install real solar system... Things will really heat up

[Sharpy]

11 minutes ago, Jaeleth said:

well, bear in mind that this is kerbin, not earth, reentry speeds are 3.5 times  lower and so it is acceptable that lots of gear survives reentry even without shielding, some should take damage, yes, but probably not complete stuctural integrity loss.
 

I'm well aware of that. No unshielded fragile structures can survive Earth reentry. The intakes wouldn't need to *just* be closed, they'd need to be closed with heavyweight heatshields.

OTOH most of the heat hits the front-facing surface. I believe ramjet combustion chamber could survive without extra protection (other than needed to survive ramjet action.)