Aero and Thermo in 1.0.X

[Hughmungus]

This might just be me, but I've found that rolling the craft around, not on, but in a circle around either prograde or retrograde, with out a heat shield, I don't overheat and die like I should. This might just be me, my computer and the mods I use, but I was wondering if anyone else had it and that if it is more than me, is there a way to change re-entry heating to kill me like it should?

[youkofoxy]

my opinion? just make the atmosphere bigger (from 70 km to 100 km).

and the aerodynamics model need improvements, I played with NEAR, and the new model don't feel right...

[Rath]

What I really hate is the Nerv heat production-not because it is unrealistic, but because it is immersion breaking. What I suggest instead is making the reactor need a different type of fuel that is consumed if the reactor is on, which allows the engine to start. Reactor starting could have a loooong spool up time and a LOT of heat production that stops when propellant starts to cool it.

[Tyren]

My oppinion: give ferram4 mucho monetas and buy his FAR/NEAR....if he'd be willing to do so.

[Ruthgar]

My biggest issue with the latest patch is the need for putting wings on your earliest rockets to keep them from going end over end. In real life I've spent over 20 years working on and around space lift systems, and I know for a fact that the primary means of steering of the rocket under thrust is the use of thrust vector control or gimballing of the thrust nozzles along the x/y axis. The main reason why you ever see a rocket start to spin end over end is usually because of a failure of one or more of the servo motor control systems of the nozzles and one or more of the nozzles being forced by the engine thrust itself to the furthest possible travel of the nozzle and locking into that position. Now requiring the use of wings/rcs to control the spin of the rocket LENGTHWISE is perfectly understandable, practical, and even applicable to real life.

Glad I've got multiple versions of KSP saved because of wanting to continue various builds/campaigns under certain conditions, as I won't be playing the updated version until the end over end flipping for no real reason gets resolved.

PS. that thrust vectoring I talked about has been on both liquid and solid rocket engines for space lift since the 50s at least in the US.

[tater]

I decided to deorbit a lander (with a probe core) that was in a near Mun SoI, eccentric orbit. I had switched the crew to a reentry vehicle...

Turns out that this transfer was a waste of time and effort. I deorbited from just below mun encounter directly to Kerbin using all my remaining fuel and RCS. Not to a low kerbin periapsis, but near vertical, straight into the ground. For a lark I rode it in, pointed retrograde. No fuel left, no mono for the RCS.

I broke one landing leg, and the engine.

[Gameslinx]

Small bug:

It always, always makes it so that the cockpit or pod faces the reentry, or programs marker upon entry heating. Steering is impossible due to physics, RCS barely moves the craft and kerbals can't hold on!

[Wjolcz]

I noticed that atmo skipping like IRL shuttle Apollo did (and what i menaged to do in NEAR) isn't really possible. At least I couldn't replicate that. I'm guessing it's a drag problem. Would be awesome if it was possible:

https://en.m.wikipedia.org/wiki/Skip_reentry

Apart from that the new aero is pretty awesome

E: after some research it seems only Chang'e and something else managed to do that, but it's possible.

Edited June 14, 2015 by Veeltch

[Azimech]

Thermal system:

You can increase the temp of an object using a "candle flame" until it reaches 2000 degrees and breaks. In reality heat dissipation is not static but depends on ambient temperature/surrounding medium and heat capacity. I think I remember a part with a higher heat capacity tends to lose heat faster than the ones with a lower value - which is the opposite of reality. And there is no cooling from airflow.

These flaws make it that I rather not use the thermal system at all.

[sarbian]

The current system is not static at all. Ambient temperature, part surface and flow are used. And there are other parameters.

[Azimech]

Unfortunately I haven't seen any proof of that, using unmodified settings.

[NathanKell]

Turn on 'show thermal data'

Keep a craft on the launch pad, watch its parts' temperature over a few days (note the diurnal pattern).

Then, go to Kerbin's pole, do the same test.

[Rickenbacker]

We need dedicated radiators, if we're to have heat. And the best, easiest way to handle those, IMO, is to make them work like the batteries and electricity producers do - if you have any radiators installed, any heat generated anywhere gets transferred to them automagically through invisible heat pipes, and radiated at whatever rate the radiators can handle. Any heat the radiators CAN'T handle gets transferred to the parts next to the heat source, the way it works now.

This should probably also apply to reentry heat, but that wouldn't make it an easy cheat to avoid the weight of heat shields, as any decent size radiators would probably break off from aerodynamic forces during reentry. So heatshields would still be needed there.

No need to make it overly complicated. We need radiators that let us use hotter engines, and we need a reason to use heat shields. The above suggestion covers both, I think.

Edited June 16, 2015 by Rickenbacker

[Azimech]

Air flow cooling doesn't work.

How flow should work: made a tiny mod for this.

http://forum.kerbalspaceprogram.com/threads/124452-Air-cooling-experiment

[RocketBlam]

I like the new aerodynamics and heat system.

In most ways, building spaceplanes is easier with the new system, because the wings and bodies provide more lift. In fact I was never able to build a large SSTO spaceplane until this patch came out.

The heat system works well too, with the obvious reservation that the heat indicators are buggy and cause the game to crash.

[SpaceFox]

Not exactly sure if this applies to the thermal part but a lot of times after I jettison the fairing (30-50 km) the parts on my satellites overheat and an overlay appears on the part. (Normally they would explode at that point so I chose the ignore max temperature cheat in the debug menu.) I haven't found anyway to decrease the heating on the parts to make the overlay disappear. If there isn't already a way to do so it would be awesome if there could be a way to toggle whether or not the overlay on the overheating parts appears. Thanks!

P.S. I'm not referring to the temperature gauge.

Edited July 18, 2015 by SpaceFox

[ZentroCatson]

Man, I love the new aerodynamics and heat system! I did a space shuttle style reentry today, it really amazed me how well it was going. Just like the real shuttle I decelerated in the upper atmosphere with a max G force of 1.5G, afterwards I glided that thing to a landing on the runway. Sadly I can't put a screenshot of my reentry here, because silly Imgur gives me "todays best images" instead of the image manipulation panel !

[carmonben]

In an effort to collect discussions, feedback, concerns, and accolades

-Claw

not sure this is where i should put this, but i think a little sound effect and maybe a little shock wave effect when you bypass the speed of sound would be a nice addon.

Carmonben

(just found forum, and i had never been to the ksp main website before today... even though ive been playing for more than a year)

[youkofoxy]

by me I'd get all the code, responsible for the heat system, and throw it in the nearest trash can.

it lacks several things as: thermal shock, change of Thermal Properties, change of mechanical Properties ....

and who said a dry fuel tank explodes when exposed to room temperature?

it is made of what? explodonium?

on the aero dynamics, is "acceptable", but could use some improvements (serious Improvements).

more important to me than adjust the aero dynamics is to treat the syndrome of the water table with tessellation.

seriously, the frames per second passes from "not good" to "excellent" just pointing the camera at Kerbol, and everybody here knows that look at a star is not healthy.

[cantab]

On the heating system, I've found it easily becomes unusable due to how prone parts are to overheating and exploding seemingly at random. Now I just go around with the heatproofing cheat on. I believe, but cannot of course prove not having access to Squad's source, that these overheating issues are symptoms of a fundamental numerical instability caused by using an inappropriate algorithm. It's an easy mistake to make by someone who isn't an expert in relevant fields of maths and computing, and is definitely something that warrants looking at for 1.1. To underline, if my belief is correct then 'tinkering' with the code won't fix it, what is needed is a full rewrite of the relevant code to use an appropriate algorithm, which is something that requires Squad to gain some expertise in the matter.

[tater]

I had a deep space probe with a nerva on the back, and 2 probes forward (an orbiter, and a lander). At the very top of the stack (orbiter), I had a high gain antenna, top middle. I had 2 large, folding radiator arrays, and 2 large flat ones on the tank in front of the nerva. Zero heating issues at all... except the high gain exploded, taking both the orbiter's solar arrays with it.

[Weywot8]

I noticed that atmo skipping like IRL shuttle Apollo did (and what i menaged to do in NEAR) isn't really possible. At least I couldn't replicate that. I'm guessing it's a drag problem. Would be awesome if it was possible:

https://en.m.wikipedia.org/wiki/Skip_reentry

Apart from that the new aero is pretty awesome

E: after some research it seems only Chang'e and something else managed to do that, but it's possible.

I've done the Apollo one-skip a number of times in-game. But its actually a reentry that lowers apoposis to 0-20km above the atmo followed by another reentry a few minutes later that does the final capture.

[Drelam]

My opinion:

New thermo system doesn't add anything interesting/good. If i where interested in a more dangerous reentry system i'd use the deadly reentry mod.

Apart from that, it's just a source of even more annoying bugs with no gain of fun or challenge at all.

[Wjolcz]

I noticed that when entering Jool's atmosphere everything decides to heat up super fast (split second fast) and explode. Don't aerobrake there. Use Tylo assist instead.

Anyone else encountered that?

[disoculated]

I really like having heat as a problem to deal with, bu I don't like *something* about the new thermal system. I'm just not exactly certain what it is. I do know that with pre-stock DRE I could do things like put delicate parts on the backsides of SSTOs so they didn't blow up on re-entry, and now that doesn't work at all... my airbrakes and fuel cells always burn up if they're connected to an empty tank (but don't if they're connected to a full tank!). Ships seem to randomly gain and lose heat with warp, sometimes explode for no reason, and none of the supposed heat-reducing parts do much of anything.

Speaking of heat-reducing parts, today I deleted KSP, then reinstalled from Steam. Then I started a sandbox, created a ship consisting of a single 2.5m probe core, a mk3 liquid fuel tank, 12x Radial Attachment Points, 12x LVN engines, and 8 launch clamps. Then I launched the craft and turned on debug thermal info.

Picture of testbed: http://i.imgur.com/mUYwmLu.png

After firing the engines to exhaustion on the pad 3 times for each config (remaining clamped to the ground), I got the following as the avg peak temp of the fuel tank after 3 runs attaching various heat-reducing parts to the tank:

545.3 - No thermal additions

536.0 - 8 large radiators

508.5 - 8 medium thermal control system panels (deployed)

540.0 - 8 medium thermal panels (undeployed)

504.3 - 8 large thermal control system panels (deployed)

525.3 - 8 large thermal control panels (undeployed)

426.1 - 1x additional mk3 fuel tank (fuel locked)

In all cases, the engines (obviously the hottest part) peaked within a few tenths of a degree of 560.

This isn't a perfect test, I know, and there's a lot more that I could do to investigate further (vacuum vs air, larger vs smaller mass, longer time, etc), but I think this does show that radiators are useless, you need a stupid amount of TCS to even make a small dent in heat, and if you really want to survive a high heat environment you're better off increasing your thermal mass instead of adding any of your current options for cooling. Even worse, NONE of the above changed the heat of the engines themselves... we've got NO option to try and control engine heat?

Anecdotally, as I mentioned before, I know that my spaceplanes survival rates are MUCH better when they re-enter with full tanks.

Summary and TL;DR - I enjoy the game and like having heat as a problem, but I want more/better options to deal with it, because the current options aren't very good.

Edited September 4, 2015 by disoculated
Fixed link