Fastest aircraft possible

[mk1980]

do you realize that jet engines have an efficiency curve and simply stop producing thrust at some point when you get too fast?

for the rapier engine, that point is somewhere around mach 5.75 i think, and it's technically impossible to accelerate past that point in "airbreathing mode". surviving the heat at that velocity is a non issue, so the challenge boils down to how close you get to the theoretical maximum.

i predict that any half serious attempt will end up somewhere in the range of mach 5.6-5.7, so the challenge seems a bit pointless.

[Cunjo Carl]

2 hours ago, mk1980 said:

i predict that any half serious attempt will end up somewhere in the range of mach 5.6-5.7, so the challenge seems a bit pointless.

   Yeah, I ran in to this one, too! It's funny, because engine-curve-wise, the Wheesley is the finest engine there is . Sadly it doesn't operate at high enough altitudes to be useful :/ .

    For the escape velocity race challenge, I put quite a bit of work into hypersonic mesospheric flights in FAR, and found the top limit of my rapier attempts were.... I believe it was just shy of 2000m/s. There's some interesting design happening in that region, and there is joy in designing a thing to push you ever closer to some asymptotic barrier (good L/D and very low parasitic drag will be the determining factors here), so I think there's enough of interest to have some fun at it!

   I just checked, and I can't find my old rapier plane (becoming a theme with me), so I'll whip up another one this evening. I hope some of the design rules will get people a start at pushing their own planes ever closer to that limit. It's hard not to have fun screaming through the atmosphere at mach 6!

[herbal space program]

12 hours ago, Gman_builder said:

Thanks for ruining my enthusiasm towards a harmless speed challenge. Go be the Batman of some other forum and deliver your forum justice there. This place is not Gotham city, we are all friends here, no need to be so mean to some guy just having fun.

Would you please calm down? I am not here to persecute you or anybody else, and I certainly do not regard myself as some kind of self-styled vigilante delivering "forum justice". I bluntly stated my own, personal opinion as one long-time forum participant that challenges that pretend to be about building the best craft, but are actually just about jockeying for likes and OP approval (which is exactly what you originally posted was) are not  really "harmless". They in fact threaten to turn this forum, which I personally hold dear, into a mockery of what I want for it to be.  I am really not in the habit of engaging about stuff like this, but I got pulled in by your bait-and-switch headline, and who will speak up for me and what I want if I don't? Anyway, since you seem so upset I must now repeat in my defense that  I made exactly ONE unsolicited comment to that effect, after which you pretty much demanded all of the subsequent statements from me by repeatedly quoting me and requiring I justify myself. I am sorry if some parts those statements hurt your feelings, but they were every one of them completely Ad Rem and not Ad Hominem, unlike what you have now come back at me with. Anyway, I have let this go on way too long already, and I will definitely have nothing further to say about it. I hope when you get over your outrage you will see that there was nothing at all personal about this, and that since you have now changed your challenge to actually being about the plane, you are getting  interest from some highly proficient people who are into building extreme planes.

Edited June 29, 2016 by herbal space program

[Violent Jeb]

[redacted, done]

Edited August 16, 2016 by Violent Jeb

[He_162]

If you guys wanna go fast, and not worry about overheating issues, just use fairings, and high heat tolerance parts, and put the fuel tanks and engines behind a fairing cover.

 

Now if you want the best vehicle for this submission, you gotta balance some things.

Get JUST the right amount of air intakes, because they each have a certain amount of air they will bring in a second, and your engine needs a specific amount per second to operate at it's best.

So to get your engine operating the best with the least drag means you must only use as many air intakes as is needed, to prevent unneeded drag.

 

Then you must have a low drag vehicle, so very little wing surfaces.

This means you need something to turn the vehicle that is heat tolerant, like these nice little 2400k tolerant wing canards.

 

The Kerbal is placed in the little openable storage container that has a super high K tolerance.

I put a drone core, and couple SAS units with some batteries and RTG's in the nose to counter the engines weight, and allow more stability.

I then placed the winglets so that at mach 6 the center of lift would be right behind the center of mass, but still stable.

So now I have a mach 5.75 capable aircraft, I will be doing more tests with this kind of vehicle, so expect test results later!

 

Edited June 29, 2016 by He_162

[Gman_builder]

10 hours ago, Blaarkies said:

How is that an average response...that was a pun, sorry for my bad jokes("mean" is a synonym for "average", more often used in statistical analysis)
You shouldn't let all this get on your nerves so easily, nobody hates you or your challenge. They just fear that one day more challenges will follow some "likes = points" scoring system. Some of us had "not so popular" lives, but this forum doesn't care about who has friends or not, all is fair and everyone is happy...but if someone has 20 good friends on his account, and they see him post a medicare plane, but they can make him win just by each clicking a button...well yes they will do it. You are correct, it is just a game, but these challenges made it sort of like multiplayer(players can share similar experiences) and that makes it an important part of the "game" to some people, take that away and you take away half the fun in it. The criticism they gave didn't give a full list of what the rules should be(then they could have just made a new challenge), they only pointed out that the "likes" point system is flawed.

Yes I get the batman references and stuff, but maybe he is just a really active forum member, appreciates the community and doesn't want to lose it...thus the "hero posts"

This post really has no point so i will make one :
Put up pictures(and stats) of all the entries on a special poll topic. Every one has 1-2 votes to pick the best craft(which are all anonymous except for pictures and stats). You will know who won and announce it later on...people can still "show" their friends which picture is theirs(but at least it takes way more effort). Some effort on your part though, but members might really appreciate that as the new way to do challenges maybe?

I told you both several posts ago I changed the rules. Stop arguing your point. You've obviously(to my dismay) won.

8 hours ago, mk1980 said:

do you realize that jet engines have an efficiency curve and simply stop producing thrust at some point when you get too fast?

for the rapier engine, that point is somewhere around mach 5.75 i think, and it's technically impossible to accelerate past that point in "airbreathing mode". surviving the heat at that velocity is a non issue, so the challenge boils down to how close you get to the theoretical maximum.

i predict that any half serious attempt will end up somewhere in the range of mach 5.6-5.7, so the challenge seems a bit pointless.

Well, the challenge is to make a aircraft faster than your competitor's. So if your sure you can make something that fast than do it and post it here!

6 hours ago, herbal space program said:

Would you please calm down? I am not here to persecute you or anybody else, and I certainly do not regard myself as some kind of self-styled vigilante delivering "forum justice". I bluntly stated my own, personal opinion as one long-time forum participant that challenges that pretend to be about building the best craft, but are actually just about jockeying for likes and OP approval (which is exactly what you originally posted was) are not  really "harmless". They in fact threaten to turn this forum, which I personally hold dear, into a mockery of what I want for it to be.  I am really not in the habit of engaging about stuff like this, but I got pulled in by your bait-and-switch headline, and who will speak up for me and what I want if I don't? Anyway, since you seem so upset I must now repeat in my defense that  I made exactly ONE unsolicited comment to that effect, after which you pretty much demanded all of the subsequent statements from me by repeatedly quoting me and requiring I justify myself. I am sorry if some parts those statements hurt your feelings, but they were every one of them completely Ad Rem and not Ad Hominem, unlike what you have now come back at me with. Anyway, I have let this go on way too long already, and I will definitely have nothing further to say about it. I hope when you get over your outrage you will see that there was nothing at all personal about this, and that since you have now changed your challenge to actually being about the plane, you are getting  interest from some highly proficient people who are into building extreme planes.

Ok, I may have overreacted a bit. But there is no need for someone to post such aggressive comments on a forum topic. I changed the rules to please you.

[boomchacle]

On 6/28/2016 at 2:56 PM, herbal space program said:

What do you mean "what"? In the headline, you represented this as a challenge about building the fastest plane, which is a challenge that could be interesting if the rules were well thought out (which by the way yours are not), and is the reason I bothered clicking on it. Once we look at the fine print however, we find out that it is in fact only a challenge about grubbing for likes and about winning the approval of your most excellent anonymous self. Most grownups who are interested in testing the limits of what is possible in this game are going to be turned off by that.

This challenge clearly states fastest AIRCRAFT. I don't see how you think that the rules are unfair. An aircraft only uses jet engines and it makes sense to do things like this. Using rocket engines wouldn't be pushing the limits at all, because you could then just go above the operational limits of all jet engines.

[Gman_builder]

13 hours ago, He_162 said:

Settle down guys, Herbal was being rude, that should be the end of it.

Now back to having a tasteful conversation.

 

Are we allowed to modify an engines config to allow it to work past the speed limit the jet engines have in-game, basically allowing much greater speeds (excess of mach 21)?

Ya actually that would be cool. I don't know how to do that myself but go right ahead!

[herbal space program]

12 minutes ago, boomchacle said:

This challenge clearly states fastest AIRCRAFT. I don't see how you think that the rules are unfair. An aircraft only uses jet engines and it makes sense to do things like this. Using rocket engines wouldn't be pushing the limits at all, because you could then just go above the operational limits of all jet engines.

Oy. I was objecting to the original rules of the challenge, which stated that entries would be scored solely on likes and OP's own impressions, which is something for which I have a visceral dislike. OP has since changed the rules to make it into an actual challenge about speed, with which I have no problem at all. Stating my opinion about the original rules in the terms that I did in the first instance was obviously a mistake. Please let's stop talking about it now.

Edited June 29, 2016 by herbal space program

[Der Anfang]

11 hours ago, Blaarkies said:

HSome of us had "not so popular" lives, but this forum doesn't care about who has friends or not, all is fair and everyone is happy...but if someone has 20 good friends on his account, and they see him post a medicare plane, but they can make him win just by each clicking a button...well yes they will do it.

A medicare plane??! I didn't know president Obama wanted planes on this health insurance plan! Sign me up! Or.... is it health insurance while on this plane? A medicare plane plan... 

Kerbal engineering just got serious.  

[Matuchkin]

6 hours ago, herbal space program said:

Would you please calm down? I am not here to persecute you or anybody else, and I certainly do not regard myself as some kind of self-styled vigilante delivering "forum justice". I bluntly stated my own, personal opinion as one long-time forum participant that challenges that pretend to be about building the best craft, but are actually just about jockeying for likes and OP approval (which is exactly what you originally posted was) are not  really "harmless". They in fact threaten to turn this forum, which I personally hold dear, into a mockery of what I want for it to be.  I am really not in the habit of engaging about stuff like this, but I got pulled in by your bait-and-switch headline, and who will speak up for me and what I want if I don't? Anyway, since you seem so upset I must now repeat in my defense that  I made exactly ONE unsolicited comment to that effect, after which you pretty much demanded all of the subsequent statements from me by repeatedly quoting me and requiring I justify myself. I am sorry if some parts those statements hurt your feelings, but they were every one of them completely Ad Rem and not Ad Hominem, unlike what you have now come back at me with. Anyway, I have let this go on way too long already, and I will definitely have nothing further to say about it. I hope when you get over your outrage you will see that there was nothing at all personal about this, and that since you have now changed your challenge to actually being about the plane, you are getting  interest from some highly proficient people who are into building extreme planes.

I would like to support your opinion on what this forum should be. However, your calling this challenge a "middle-school popularity contest" with his own "arbitrary impressions thrown in",  "facebook-style BS" and your claim that you were successful in "defending" this forum from posts like this is entirely ad-hominem. After all, all challenges include this, and all good challenges gain the OP likes, not because the OP is an egotistic scum but because the challenge is good.

[boomchacle]

20 minutes ago, herbal space program said:

Oy. I was objecting to the original rules of the challenge, which stated that entries would be scored solely on likes and OP's own impressions, which is something for which I have a visceral dislike. OP has since changed the rules to make it into an actual challenge about speed, with which I have no problem at all. Stating my opinion about the original rules in the terms that I did in the first instance was obviously a mistake. Please let's stop talking about it now.

OK. I wasn't here for the original rules, so I didn't see what you were talking about.

[Grenartia]

3 hours ago, Gman_builder said:

Ya actually that would be cool. I don't know how to do that myself but go right ahead!

I'd like to request that such submissions be put into a separate, "modded" category, so that those of us using stock parts aren't at a disadvantage.

[He_162]

52 minutes ago, Grenartia said:

I'd like to request that such submissions be put into a separate, "modded" category, so that those of us using stock parts aren't at a disadvantage.

I agree completely, or I could simply release the edited configs that aren't limited to a specific top speed, so that all of them are allowed.

 

I got a aircraft to get an intercept with the mun whilst still in the atmosphere a while back with modded configs, if that counts.

It used rapiers with modded textures to look better, and a mod's intakes which produced the same amount of drag as if I put side mounted intakes to get the same airflow, so it wasn't OP either.

Top speed was roughly 3000 m/s I think.

 

Here was my other previous attempt with unrestricted modded configs.

It also had a pork-alike rapier, which has the same stats as the usual rapier + my modded config so that it didn't just stop working at mach 5.75.

Top speed, 3071.8 m/s (give or take 10 m/s for dive / climb speeds)

 

Then if you wanna be really crazy I got an aircraft with a rapier (with an OP modded config to allow full thrust at 65,000m, so it isn't valid)

I have this thing... 7,204 m/s top speed, which is considered high hypersonic - ultra hypersonic (re entry speeds)

Edited June 30, 2016 by He_162

[Gman_builder]

1 hour ago, Grenartia said:

I'd like to request that such submissions be put into a separate, "modded" category, so that those of us using stock parts aren't at a disadvantage.

Alright, that's super easy. Done!

47 minutes ago, He_162 said:

I agree completely, or I could simply release the edited configs that aren't limited to a specific top speed, so that all of them are allowed.

 

I got a aircraft to get an intercept with the mun whilst still in the atmosphere a while back with modded configs, if that counts.

It used rapiers with modded textures to look better, and a mod's intakes which produced the same amount of drag as if I put side mounted intakes to get the same airflow, so it wasn't OP either.

Top speed was roughly 3000 m/s I think.

 

 

Here was my other previous attempt with unrestricted modded configs.

It also had a pork-alike rapier, which has the same stats as the usual rapier + my modded config so that it didn't just stop working at mach 5.75.

Top speed, 3071.8 m/s (give or take 10 m/s for dive / climb speeds)

  Hide contents

 

Then if you wanna be really crazy I got an aircraft with a rapier (with an OP modded config to allow full thrust at 65,000m, so it isn't valid)

I have this thing... 7,204 m/s top speed, which is considered high hypersonic - ultra hypersonic (re entry speeds)

 

Ok that's kind of ridiculous. Honestly that's not really an aircraft anymore lol. More of a air augmented rocket.

[vosechu]

Do you mind reposting this challenge with the new rules in place? There aren't many entries, so maybe a rewind now that the rules are discovered might be helpful.

[Grenartia]

Just now, vosechu said:

Do you mind reposting this challenge with the new rules in place? There aren't many entries, so maybe a rewind now that the rules are discovered might be helpful.

Or, you know, just edit the OP.

[vosechu]

1 minute ago, Grenartia said:

Or, you know, just edit the OP.

My concern is not the OP, it's the two full pages of arguments that keep me from reading about awesome attempts. 

Anyways, I'm unsubscribing from this thread regardless. 

Edited June 30, 2016 by vosechu

[Cunjo Carl]

9 hours ago, He_162 said:

If you guys wanna go fast, and not worry about overheating issues, just use fairings, and high heat tolerance parts, and put the fuel tanks and engines behind a fairing cover.

Right on, the fairing's a great way to go! Very close to it (surprisingly) is the inflatable nose cone. The inflatable nose cone provides much better thermal protection and stability at a slight drag cost. For me, it's worth it in droves, but I suspect your design will push closer to the mach 6 limit in the end. I'm accustomed to this design style from my work in the Escape Velocity: The Hypersonic Race, where the substantially greater speeds allowed by NERVs (never thought I'd say that) necessitate the higher heat tolerance.

This craft flies mach 5.7ish in both stock and FAR, and has a few interesting design points. Shock cones (hands down the best air intake for our purpose) can be mounted inside the inflatable heat shield cage using radial attachment points on whatever is connected to the heat shield. There's room for 4 in there with minor clipping. This protects the intakes without occluding them. Underneath the inflatable heat shield, it's convenient to put a 2.5m service bay for all your things. Cores, batteries, science, and Kerbals all fit in here nicely. Service bays make the best command pods!

As we scale up, the drag from the heat shield becomes progressively lower relative to the thrust, so we start getting faster and faster. Click through the pictures to see the step by step improvement- Here we go!

 

Hey, we've been discussing speed in terms of mach number, which I think is a great way to do it. In FAR (which I'm using for some reason), it's very easy to determine your mach number. You can simply type in a mach number and an altitude, and it provides you the speed. How are people calculating mach numbers in stock?

Finally, there's many silly ways to make your plane less draggy in FAR, like putting BigS strakes all over it, like a flattened porcupine. I'm starting to feel the temptation!

[Grenartia]

3 minutes ago, Cunjo Carl said:

Right on, the fairing's a great way to go! Very close to it (surprisingly) is the inflatable nose cone. The inflatable nose cone provides much better thermal protection and stability at a slight drag cost. For me, it's worth it in droves, but I suspect your design will push closer to the mach 6 limit in the end. I'm accustomed to this design style from my work in the Escape Velocity: The Hypersonic Race, where the substantially greater speeds allowed by NERVs (never thought I'd say that) necessitate the higher heat tolerance.

This craft flies mach 5.7ish in both stock and FAR, and has a few interesting design points. Shock cones (hands down the best air intake for our purpose) can be mounted inside the inflatable heat shield cage using radial attachment points on whatever is connected to the heat shield. There's room for 4 in there with minor clipping. This protects the intakes without occluding them. Underneath the inflatable heat shield, it's convenient to put a 2.5m service bay for all your things. Cores, batteries, science, and Kerbals all fit in here nicely. Service bays make the best command pods!

As we scale up, the drag from the heat shield becomes progressively lower relative to the thrust, so we start getting faster and faster. Click through the pictures to see the step by step improvement- Here we go!

 

Hey, we've been discussing speed in terms of mach number, which I think is a great way to do it. In FAR (which I'm using for some reason), it's very easy to determine your mach number. You can simply type in a mach number and an altitude, and it provides you the speed. How are people calculating mach numbers in stock?

Finally, there's many silly ways to make your plane less draggy in FAR, like putting BigS strakes all over it, like a flattened porcupine. I'm starting to feel the temptation!

It took you 24 Rapiers to get 0.01 Mach better than my 1 Rapier design? I think I'm winning this from an efficiency standpoint.

Also, I use MJ for Mach number calculation. So its not a total stock design, but since I'm not using MJ's piloting functions, I'm confident I'm within the spirit of the challenge. Also, I discovered early on that BigS strakes are the way to go. Really, its the only way to minimize drag without turning your plane into a jet missile. Plus, extra fuel storage never hurts. I keep the BigS deltas for the mothership.

[Cunjo Carl]

1 hour ago, Grenartia said:

It took you 24 Rapiers to get 0.01 Mach better than my 1 Rapier design? I think I'm winning this from an efficiency standpoint.

Haha, right? It's all about the style, and mine is go big! Speaking of which, not sure if I'll finish it, but here's my 112 engine version

Yes, it's crashing; no, that doesn't make it any less beautiful in my eyes.

MJ for informational makes sense, and I've just found that KER has a mach number readout as well. If you happen to have KER would you mind checking it for consistency with MJ? I'll do the same with FAR. I'm hoping we can find a way to make a level playing field- these first few .01machs will be easy to trade, but the later ones will only get more tricky.

Good luck with your little rapier rocket!

Edit: @He_162, I like your plane- it's also a nice simple design! Say, how are you measuring mach? I think mach is a good common ground for people to vie on because it's directly tied to the thrust curves, and I'm hoping to figure out if mach here is the same as mach there.

Edited June 30, 2016 by Cunjo Carl

[Blaarkies]

██████
████  ███████  ███.  ███  █████████  █  █████ ███  ███ ,

██  █████████  █  █████ ███ .

Edited July 1, 2016 by Blaarkies
redacted because █████ and ███.

[Nefrums]

This is just about maximizing thrust/drag.   The thrust from rapiers drops of with speed and is close to 0 at mach 5.8.

Best I could do was mach 5.79...

 

[He_162]

3 hours ago, Cunjo Carl said:

Haha, right? It's all about the style, and mine is go big! Speaking of which, not sure if I'll finish it, but here's my 112 engine version

 

Yes, it's crashing; no, that doesn't make it any less beautiful in my eyes.

MJ for informational makes sense, and I've just found that KER has a mach number readout as well. If you happen to have KER would you mind checking it for consistency with MJ? I'll do the same with FAR. I'm hoping we can find a way to make a level playing field- these first few .01machs will be easy to trade, but the later ones will only get more tricky.

Good luck with your little rapier rocket!

Edit: @He_162, I like your plane- it's also a nice simple design! Say, how are you measuring mach? I think mach is a good common ground for people to vie on because it's directly tied to the thrust curves, and I'm hoping to figure out if mach here is the same as mach there.

I use the Kerbal Engineer mach reading, and post my m/s top speed.

 

I'm waiting for someone to beat my 3000 m/s top speed...

Edited June 30, 2016 by He_162

[Grenartia]

2 hours ago, He_162 said:

I use the Kerbal Engineer mach reading, and post my m/s top speed.

 

I'm waiting for someone to beat my 3000 m/s top speed...

In what version was that again?

5 hours ago, Cunjo Carl said:

Haha, right? It's all about the style, and mine is go big! Speaking of which, not sure if I'll finish it, but here's my 112 engine version

Yes, it's crashing; no, that doesn't make it any less beautiful in my eyes.

MJ for informational makes sense, and I've just found that KER has a mach number readout as well. If you happen to have KER would you mind checking it for consistency with MJ? I'll do the same with FAR. I'm hoping we can find a way to make a level playing field- these first few .01machs will be easy to trade, but the later ones will only get more tricky.

Good luck with your little rapier rocket!

Edit: @He_162, I like your plane- it's also a nice simple design! Say, how are you measuring mach? I think mach is a good common ground for people to vie on because it's directly tied to the thrust curves, and I'm hoping to figure out if mach here is the same as mach there.

Sorry. I tried KER once, didn't really like it.