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Fastest Plane under 1.000m. [WE HAVE REACHED MACH 5!, Tidus Klein at 1,714 m/s]


m1sz

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CONCEPT:

Make the fastest plane you can at sea level (under 1.000m), that takes off from the runway.

RULES:

-Using stock parts, B9 aerospace, procedural dynamics and FAR (I dont think it's possible without FAR). [any other mod suggestions are ok, as long as their parts are not overpowered]

-As I said, take off from the runway (VTOL ALLOWED)

-You can't go over 1.000 meters at any time during the flight (it's not valid to dive from high altitude, you must reach the speed with the only help of your engine and without going over 1.000m)

-Only atmospheric engines (SABRE and RAPIER engines are alowed running in atmospheric mode)

-no cheats (infinite fuel, etc) -> includes no crazy clipping of any kind!!!!!

-NEW RULE Must have atleast 2 wings (dont care if they are small, control surfaces, or so)

-Plane has to be able to go back and land in the runway (any of them) [if you overstep a little is ok, showing enough proof that the plane can, is enough]

-NEW RULE landing has to be horizontaly, not VTOL landing allowed*

-NEW RULE as fairings seems to kill a lot of drag, it will be noted in the leaderboard so everyone can see it. (as these planes usually go all covered in fire, tell me when you use fairings in case I miss it!)

-NEW RULETake off can be vertical or horizontal, but you cant use mounts. (It's a plane challenge!)

* This rule is made to avoid rocketized airplanes. The main goal of this challenge, is to see how fast a plane can go using atmospheric engines, if you, engineers, dont have to think about landing, you dont need to be able to glide anymore, and therefore, it stops being a plane. VTOL take off is ok, since taking off is not hard, normaly, and wont make any vicious loopholes. Im sorry for adding this extra rule, it only affects one participant atm

PROOF:

-Picture of the plane at top speed (showing resources)

-Picture of the mission report (showing you didnt go over 1.000m)

-(optional) A video of your magnificent plane showing speed :)

LEADERBOARDS:

-FAR:

fluffysnowcap 737.3M/s (Mach 2.175) airplane link

1096bimu 847.9M/s (Mach 2.503) (still no proof of landing) airplane link

m1sz (myself) 645 M/s (Mach 1.9) (capable of landing, didnt make it in the video tho) airplane link

autosave 720M/s (Mach 2.12) (with video, and VTOL) airplane and video link MUST SHOW PROOF OF HORIZONTAL LANDING! (sorry, new rule!, i bet you can easily add 3 wheels and land)

Sevant 1st entry 870.6 M/s (Mach 2.562) airplane and video link

Hejnfelt 1st entry 879M/s (Mach 2.593) airplane and video link

Sevant 2nd entry 928.4M/s (Mach 2,728) airplane and video link

Hejnfelt 2nd entry 1,029M/s (Mach 3.034) airplane and video link

Sevant 3rd entry 1,090.0M/s (Mach 3,211) airplane and video link (USING FAIRINGS)

Hejnfelt 3rd entry 1,141M/s (Mach 3.364) airplane and video link(USING FAIRINGS)

Sevant 4th entry 1,186M/s (Mach 3,495) airplane and video link (USING FAIRINGS)

Sevant 5th entry 1,205M/s (Mach 3,556) airplane and video link (USING FAIRINGS)

Hejnfelt 4th entry 1,402 m/s - (Mach 4.134) airplane and video link(USING FAIRINGS)

Sevant 6th entry 1,529M/s (Mach 4,510) airplane and video link (USING FAIRINGS)

Tidus Klein 1,714M/s (Mach 5,040) airplane and video link (USING FAIRINGS)

TheHengeProphet 692.8 m/s (Mach 2.045) airplane and video link (more realistic airplane)

palker 826 m/s (Mach 2.436) airplane link (more realistic airplane, and using fairings I think)

-NON FAR

leafty 330 M/s airplane link

Fengist 362.1 M/s airplane link

Hejnfelt 381 M/s airplane link With video!!

CURRENT FAR RECORD ALBUM:

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Let's see how fast we can go!

EXAMPLE:

Here is my OP booster, I went over mach 1.5 and was able to land back. (In the video i also went over 1.000m, but the speed was reached before going over that altitude). It's a video from KSP 0.22, using FAR 0.10, Ill try to update my plane when B9 aerospace is updated to 0.23

Cheers!, I hope people likes the challenge, Didn't see any recent challenge with this rules (most of them are higher speed but not under certaint altitude)

Edited by m1sz
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I'm seeing several isues with the post above.

- Not landed on the runway (at least no proof that it did).

- No pic at top speed (or near it as I think it might be challenging to get a pic at top speed)

- Flight went over 1000m, and there is no proof that the speed was reached above the challenge ceiling.

- Isn't it the Highest Speed Achieved that we should be looking at? Not the Highest Speed Over Land?

Can I recommend a FAR and non FAR leaderboard too? Making a fast low altitude aeroplane is most deffinitely possible without FAR.

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  dinosaurJR said:
I'm seeing several isues with the post above.

- Not landed on the runway (at least no proof that it did).

- No pic at top speed (or near it as I think it might be challenging to get a pic at top speed)

- Flight went over 1000m, and there is no proof that the speed was reached above the challenge ceiling.

- Isn't it the Highest Speed Achieved that we should be looking at? Not the Highest Speed Over Land?

Can I recommend a FAR and non FAR leaderboard too? Making a fast low altitude aeroplane is most deffinitely possible without FAR.

Not interested in showing off the design before anybody else has entered.

and no it is not possible without FAR, you'll never get over 340 or so, not without seperatron abuse.

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max speed can be calculated. You need a high thrust to weight ratio for this, as mass is the only thing that matters in this equation. (and velocity ofc, but its the target variable)

Because of the low altitude you can reduce your intakes to a minimum, also to reduce drag... however there arent many options with the vanilla intakes.

In this case i would use more engines than intakes, to keep the "stored" air inside the intakes at a minimum.

Even tho the normal engines have close to 1900 ISP at this altitude (turbo about 1000 to 1200), at about 400 m/s they run at 60% whereas the turbo runs at 70%. The normal jets are almost never any good.

Edit:

my math is somewhat rusty so here is the almost final formula (some genius here can solve it :D )

(0.5 + (v / 2000)) / 0.00000356 * m = v^2

Its for turbojet and the assumption that command+control etc is of neglectable weight and that every engine requires the same amount of weight for fuel and wings etc (which it does, every engine weighs and thus requires lift and ofc fuel).

So insert m as the weight of that engine combo (imho 1.3 to 1.4 t should be sufficient).

Cuz im too stupid to solve it any further you have to insert and play around a bit but with 1,4t approx 450 m/s is max. (@1000 m altitude, 0.2 drag coeff, empty air intakes).

because of the assumptions above and the formulas, it doesnt matter how many engines you use for as long as the TWR stays the same.

Edited by NikkyD
some math
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My predictions:

Set deltaT to 0.01 (rather than the default 0.04), and build with one radial scoop and a single tonne for the cockpit and empty fuel. Assume all your propulsion is from jets.

9 turbojets at full throttle. You can go 374 m/s.

21 basic jets at full throttle. You can go 353 m/s.

10 rapiers at full throttle. You can go 275 m/s.

If you're going faster, it's due to propulsion from other things, such as lifting surfaces.

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You want as many jets as possible to use up all the air from your intake; if you're not using all the air, that's drag you're paying for without benefit. Similarly, you'll want to amortize the drag from the cockpit and tank dry mass. You can amortize the cockpit over more engines if you add intakes and jets, but I decided to keep it to one intake.

With physics deltaT at 0.01 (which means 100 physics frame per simulated second), at 1km altitude and 350 m/s you get 152 kg/s of air from the radial intake, versus just 100 kg/s from the ram, so it's the best intake. The reason is the capacity: the radial intake capacity isn't full, but the ram intake is. If you choose a smaller physics deltaT, 0.0025 (which means 400 physics frames per simulated second), the ram intake no longer fills its capacity, and you get 380 kg/s of air, 2.5x as much, which is because its area is 2.5x as much. So you could run 2.5 times as many engines. But it would be painfully slow; even at deltaT = 0.01 you're probably running at 1/3rd real time or slower.

You want to fly at 1km, because turbojet Isp (and rapier, which is the same) is much better there, so you don't need as much air per turbojet. Isp doesn't vary much for the basic jet at the low altitudes.

With those thoughts in mind (any of which might be wrong) I used this script to try a number of designs; I set the altitude to 1000, pitch and angle of attack to zero, and tried to get the throttle to 100% or maybe add an engine and make the user throttle back. Then I varied the speed so that the net acceleration was positive but close to 0.

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I did a couple of test runs and my calculation above is pretty much accurate except for the intakes air. I built a "plane" with only the necessary parts, no cockpit... 1.6t but somehow the game and/or mechjeb cant handle a Probodobodyne. It would be the lightest control interface with 40 kg but the controls are all off right is up and up is left and the plane just spins around like crazy the second i turn on SAS... sick of it

But what i wanted to know, you based the number of engines on the air available to exhaust it to a minimum and thus reduce drag to a minimum and also to reduce the amount of the cockpit weight in the overall mass to thrust... k

Edit:

With 9 engines IF they exhaust the intake, you should be able to pull off over 400 m/s or am i missing something ? 1t cockpit / 9 = roughly 111 kg, you dont need many wings and fuel for jsut a short trip is... little, about 20 units per engine. So its close to my estimated 1,4t which allow way over 400 m/s. So whats the difference ?

Edited by NikkyD
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B9 is broken for this im curently testing air intakes in cargobays to have less drag and go faster same ship twice one with out cargo bay and ram nose cone and the second one with cargo bay and nose cone the second one gose 400M/s faster easy

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Of course it is, for a given amount of predictable.

So are any results from FAR.

So are any results from real life.

It is called "Physics".

But then you need to build the thing, take off, fly it to the edge of the performance envelope you have oh so cleverly calculated (without crashing) keeping it under 1000m altituide (without crashing) and then land it on a runway (without crashing).

Without the actual flying part (without crashing) this challenge becomes so much sitting in your room alone playing with your slide rule...

As for the intake in a cargo bay thing - it makes sense to me; you elimiated the drag from the intake by placing it inside a streamlined air tank.

The broken bit, I guess, is that FAR doesn't calculate the air in the cargo bay as a resource so it doesn't take into account that the air inside the cargo bay would be used up fairly quickly, giving you an infinite supply of air and a very low drag air intake.

Bloody nice design idea, though, fluffysnowcap :

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Yes dinosaurJR with the laws of "Physics" there is one right answer and for FAR that right answer is a lot simpler game after all and uniform air wish we had that is RL and i feal that you have got my covered the bit i brought to attenuation so much more elegantly that i woud or been able to and got the hole issue i feal but i am preoccupied trying to get in to the 1000M/s club and it is hard with the loss of dynamic warp i have to use a tweaked version of mechjeb just not to spin out and crash at thows speeds

:note:

will be posting some crashes soon to give me a brake from trying

here is some of the problems i had

http://youtu.be/Jt9cv647isY

Edited by fluffysnowcap
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  dinosaurJR said:

But then you need to build the thing, take off, fly it to the edge of the performance envelope you have oh so cleverly calculated (without crashing) keeping it under 1000m altituide (without crashing) and then land it on a runway (without crashing).

Without the actual flying part (without crashing) this challenge becomes so much sitting in your room alone playing with your slide rule...

Ah c'mon. Start the engine, hit SAS, lift off, get to 1000m, hold it and wait for vmax. Turn around, land... why should it crash ? either the bird is stable or its not even reaching 1000m because of the "physics" of the game

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  dinosaurJR said:
Of course it is, for a given amount of predictable.

So are any results from FAR.

So are any results from real life.

It is called "Physics".

But then you need to build the thing, take off, fly it to the edge of the performance envelope you have oh so cleverly calculated (without crashing) keeping it under 1000m altituide (without crashing) and then land it on a runway (without crashing).

Without the actual flying part (without crashing) this challenge becomes so much sitting in your room alone playing with your slide rule...

As for the intake in a cargo bay thing - it makes sense to me; you elimiated the drag from the intake by placing it inside a streamlined air tank.

The broken bit, I guess, is that FAR doesn't calculate the air in the cargo bay as a resource so it doesn't take into account that the air inside the cargo bay would be used up fairly quickly, giving you an infinite supply of air and a very low drag air intake.

Bloody nice design idea, though, fluffysnowcap :

the difference is that with FAR, it is more difficult to predict, in fact It is so difficult, I don't think you can do it.

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  NikkyD said:
Ah c'mon. Start the engine, hit SAS, lift off, get to 1000m, hold it and wait for vmax. Turn around, land... why should it crash ? either the bird is stable or its not even reaching 1000m because of the "physics" of the game

Ah. Then, good sir, I await your winning entry with great anticipation and a dash of baited breath.

Now, can we stop whining about the bloody game and actually get some entries posted up in here?

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  Quote
Yes dinosaurJR with the laws of "Physics" there is one right answer and for FAR that right answer is a lot simpler game after all and uniform air wish we had that is RL and i feal that you have got my covered the bit i brought to attenuation so much more elegantly that i woud or been able to and got the hole issue i feal but i am preoccupied trying to get in to the 1000M/s club and it is hard with the loss of dynamic warp i have to use a tweaked version of mechjeb just not to spin out and crash at thows speeds

:note:

will be posting some crashes soon to give me a brake from trying

here is some of the problems i had

http://youtu.be/Jt9cv647isY

As i said in the youtube comment, that's a rly fast plane, but i would love to see you land that thing :P, remember, no cheats, that includes clipping (i've clarified that in the rules), (would love if you could change your plane w/o clipping, much more realistic :) )

BTW, atm there is not a valid entry, keep testing, I'm rly looking forward your planes! :D

Edited by m1sz
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