Klapaucius

G.A.S.--Goliath Altitude and Speed Challenge

Recommended Posts

VERY SIMPLE

Using only Goliath engines:

1. Go as fast as you possibly can.

2. Go as high as you possibly can.

The challenge, as you will soon see, is that Goliaths have heaps of power but a narrow altitude range of peak efficiency and a tendency to overheat. Your job is to overcome this as best you can.

 

3. BONUS challenge: Fly your craft as fast as you can from the KSC to the Dessert Airfield, or if you do not have Making History, anywhere within 3 kms of: 

6° 35′ 58″ S
144° 2′ 26″ W

 

RULES:

1. You may use any number of Goliaths.

2. You may not use any other type of propulsion at all. No other engines, no props, nothing.

3. Your craft must takeoff and land intact. (VTOL is fine).

4. You may go into a dive to get your top speed, but you still have to pull out of it (see rule 3).  I might do a separate leaderboard for sustained level flight if there is interest.

5. You may use stock heat dissipation parts (though the drag may nullify any benefit).

6. Don't go looking for loopholes. This is about design and flight profile, and as it is, it is pretty open.

7. Stock and DLCs only.

8. You may use different craft for the 3 different parts of the challenge.

9. You must have a pilot.

10. You may use up to 2 quicksaves (you can go back as many times as you like, but can only create 2 specific saves, so choose your location wisely) for the Dessert Airfield flight. I'd rather you push the limits than be too conservative.

 

LEADERBOARD:

SPEED

1. @Teilnehmer 729.4 m/s water landing

2. @Pds314   (GolFast 1.2) 728.2  m/s  water landing

3. @MiscelanousItem   416 m/s water landing1

 

ALTITUDE

1. @Teilnehmer 30,488 m

2. @Pds314  (VelociDrum) 22,465 metres

 

DESSERT AIRFIELD TIME TRIAL

1. @Pds314 (VelociDrum) 22:12

2. @klond 25:08

3. @Pds314 (GolFast 1.2) 25:55

 

MOAR!!!!!!!

HfE8sqC.png

Edited by Klapaucius

Share this post


Link to post
Share on other sites

 

1 hour ago, Pds314 said:

Reminder that this thing can go *FAST*

J-90_Goliath_Turbofan_Engine_velocity_cu

It certainly can. The challenge is heat.  I already have my contender and a run, but was waiting for some others to join in.

It is one of my favourite engines. It is so powerful and so efficient.

Edited by Klapaucius

Share this post


Link to post
Share on other sites
On 12/2/2019 at 1:53 PM, Klapaucius said:

3. Your craft must takeoff and land intact.

Are water landings allowed?

Share this post


Link to post
Share on other sites
2 hours ago, Teilnehmer said:

Are water landings allowed?

Yeah, why not?  But you can't break anything.  I'm assuming you are launching off clamps and getting rid of landing gear?  I may make a separate leaderboard for aircraft that takeoff and land traditionally. My own entry is very twitchy since it has been stripped down to nearly nothing, so I figure there is some design and flying challenge in that as well.

Edited by Klapaucius

Share this post


Link to post
Share on other sites

Failed attempt because I was dumb and used the brakes, but hey, it's a fast birb.

This aircraft may look like it has giant intakes. Alas, this is illusory. The Goliath intakes are obstructed by each other because they would cause far too much drag. The result is that it has to throttle way down at low speed in order to avoid assymetrical stall out.
TaVmEfU.png
 

Spoiler


Half the speed of sound and I still only have it at half throttle. I'm about to Z the throttle to max though.
yCBuJhh.png

680 m/s before the temp gauge shows.
hLjkeJi.png

Temp gauges are getting hot. 724.4 m/s ain't too bad though.
4hClawa.png

Pulling a 13-G zoom climb to get out of the fast air.
B00i9aA.png

We level off around 3500 meters.
TNJgiqR.png

We lower throttle to avoid a flatspin and head for the KSC.
lNFAg5z.png

Final approach.
rsFZcMh.png

Reducing speed.
Gzsnr0J.png

We nose-forward and crash.
FwbRQz5.png

 

Edited by Pds314

Share this post


Link to post
Share on other sites

OFFICIAL ENTRY: top speed of 728.2 m/s.

After many, many, MANY attempts to land it on the runway, I determined that ditching in the sea is the best option. The plane is not really optimized for this but it's better than having it skid off the end of the runway or randomly explode on touchdown. I have also changed the gear from taildragger to tricycle, but it doesn't matter much for landing since I have difficulty landing it.

Runway acceleration:
DnCfa6G.png
 

Spoiler

Takeoff:
z5TUkS5.png

680 m/s at 2.9 km on cold engines:
36SFGD6.png

728.2 m/s in a freefall dive:
9YmW9YJ.png

I pull out of the dive in a 13 G turn: only 40 meters above the water. 
gQ3YQXI.png

Turned 130 degrees to reduce speed. Initially planned to land on terrain. Decided against it:
ntGOa30.png

Preparing to land in the water:
Fi9kxHH.png

Hard landing, but nothing broken:
2X9SVqc.png

Safe and sound in the water.
ZzPkmZD.png

 

Edited by Pds314

Share this post


Link to post
Share on other sites

Sadly, it inexplicably exploded immediately afterward. It has almost exactly enough fuel to reach the place at 560 m/s cruise. Crashed at 24:55.

WvwISV3.png

mDQLEJh.png

And while I'm sure this isn't a gonna be competitive for long, I may as well submit the highest altitude it reached:

CWl9EG4.png

Share this post


Link to post
Share on other sites

OFFICIAL ENTRY: Peak altitude of 22465 meters.

A new aircraft design, meant to get more out of a zoom climb and cruise at higher altitudes. It's lacking the power of the GolFast 1.2, but the VelociDrum I needs altitude, not thrust. Thus, it has huge wings and a somewhat lighter airframe overall.

Accelerating for the climb:
F380K6i.png


 

Spoiler

Right before combustion failure:
Hj6NftW.png

Peak altitude:
eWNhLD7.png

Coming in VERY hot:
JGjnSGa.png

A loop should fix our problem:
f3RtOBP.png

Down to landing speeds:
PdUVYPM.png

Landing. Smooth as silk.
I4RLPj0.png

Stopped. I used a bit of thrust reversers to make sure it wouldn't roll of the end of the runway since the brakes are not very aggressive.
YXGGs5n.png

 

Share this post


Link to post
Share on other sites
1 hour ago, Pds314 said:

Sadly, it inexplicably exploded immediately afterward. It has almost exactly enough fuel to reach the place at 560 m/s cruise. Crashed at 24:55.

WvwISV3.png



 

I'll give this to you and just add a one minute penalty. Especially as I realized I forgot a rule I intended: namely, that for the flight to the Dessert Airfield I would allow 2 quicksaves. 

Edited by Klapaucius

Share this post


Link to post
Share on other sites
15 minutes ago, Klapaucius said:

I'll give this to you. Especially as I realized I forgot a rule I intended: namely, that for the flight to the Dessert Airfield I would allow 2 quicksaves. 

OFFICIAL ENTRY: KSC -> DAF in 22:12.

That won't be necessary. I flew my other plane to the Dessert airfield for a runway landing. With a higher cruise speed, less fuel usage, and more direct route too.

Flipping around. Where we're going, we don't need roads.
CteYyow.png

 

Spoiler

3800 meters and 500 m/s within one minute.
QNTI4gu.png

above K2 in two minutes.
ZWzZKl1.png

Thermometer gauge shows up for the engine. Not a problem.
0yEcRUP.png

Oh.... ok. Yes a problem Too many gauges! Go away! Please no kill Val!
nicOdAQ.png

Taking some photos of the pyramids while praying to the heat gods not to kill Val.
gO9JMQw.png

This is totally reasonable and perfectly normal for a descent.
eg2kB3P.png

And we are on the runway!
1kGTS7X.png

And come to a stop. Still overheating. Val plans to immediately get out of the cockpit in case it catches fire.
ZUS3XUn.png



 

Edited by Pds314

Share this post


Link to post
Share on other sites

Uh.... oh.... that's.. not good.
VTOL might be harder than I hoped.
RQRghBP.png
 

Edited by Pds314

Share this post


Link to post
Share on other sites

Question: is deliberate staging of things allowed? And if so, what?

Mainly thinking of drop tanks, takeoff skis/gears, and possibly intakes.

Share this post


Link to post
Share on other sites
5 minutes ago, Pds314 said:

Question: is deliberate staging of things allowed? And if so, what?

Mainly thinking of drop tanks, takeoff skis/gears, and possibly intakes.

No, unless we create an unlimited class. Which is possible.

Share this post


Link to post
Share on other sites

Hmmmmmm... I might experiment with BG parts and see if I can't make the engines generating thrust move backward relative to the rest of the vehicle. Either reciprocally or (more likely) rotorallerorilllarorally.

Edited by Pds314

Share this post


Link to post
Share on other sites
2 hours ago, Pds314 said:

Uh.... oh.... that's.. not good.
VTOL might be harder than I hoped.

 

I made a VTOL with Goliaths once (too much drag for this challenge). I wound up using chutes. They are insanely difficult to land because the engine takes so long to spool up.  I've done it, but it was like a 2% success rate.

https://kerbalx.com/Klapaucius/Bradbury-VTOL

Share this post


Link to post
Share on other sites
21 minutes ago, Klapaucius said:

I made a VTOL with Goliaths once (too much drag for this challenge). I wound up using chutes. They are insanely difficult to land because the engine takes so long to spool up.  I've done it, but it was like a 2% success rate.

https://kerbalx.com/Klapaucius/Bradbury-VTOL

Goliath VTOLs are so cool. But yeah the spooling time makes them impractical. One workaround is violently shutting them off. Either with "shutdown engine," "close intakes" or physically obstructing their exhaust.


Oh also I noticed two things.

1. The GolFast 1.2 did the run in 24:55. Not 25:55.

2. The VelociDrum I did the run in 22:12 but is not listed in the OP?

Edited by Pds314

Share this post


Link to post
Share on other sites
8 hours ago, Pds314 said:

Goliath VTOLs are so cool. But yeah the spooling time makes them impractical. One workaround is violently shutting them off. Either with "shutdown engine," "close intakes" or physically obstructing their exhaust.


Oh also I noticed two things.

1. The GolFast 1.2 did the run in 24:55. Not 25:55.

2. The VelociDrum I did the run in 22:12 but is not listed in the OP?

Sorry, did not see the VelociDrum run. As for the other, I gave a minute penalty since you exploded and would have taken time to land.

Share this post


Link to post
Share on other sites

David craft

  • Max speed: 729.4 m/s
  • Max altitude: 30 488 m
  • Water landing

pflvmkV.png

 

 

Edited by Teilnehmer

Share this post


Link to post
Share on other sites
9 hours ago, Teilnehmer said:

David craft

  • Max speed: 729.4 m/s
  • Max altitude: 30 488 km
  • Water landing

Nice!  Are the side nacelles dissipating some of the heat?  

@Pds314 He bested you by 1.2 m/s.  Are you going to let that stand? :wink:

Edited by Klapaucius

Share this post


Link to post
Share on other sites
3 hours ago, Klapaucius said:

Are the side nacelles dissipating some of the heat?

Yes, they seem to do it pretty well. The key thing is to place a precooler immediately onto the engine with no parts in between. So in my craft,  the left-side precooler is placed onto the rear engine and the right-side one onto the front engine (which is placed backwards and has thrust reversion).

KerbalX is down now for some reason, so here’s the craft file.

Share this post


Link to post
Share on other sites
On 12/4/2019 at 4:57 AM, Pds314 said:

or physically obstructing their exhaust.

 

 Now this is some good thinking to bypass that slow spooldown.

 

  I have really enjoyed this challenge.  This is about heat like you guys said. 

 

 Made several craft changes and many reverts (I only used one quicksave per run, 3/4 of the way each time) and spent several hours flying bad craft (some craft didn't like time warp).   Some of my rockets with radiators on the outside couldn't get over that mach hump (350ish is it?).  THIS is my only success without burning up.  Even though I'm on the slant it didn't tip :).  I use 385 units of fuel I think (tried to stay at high altitude).

 It seemed I had less engine heat problems if I made my final approach more square then to efficiently angle down for max speed/shortest distance.  I wonder if ya'll that mask the front of your engine develop less drag heat.

 Here I ended up jamming my only engine into reverse at 1000-2000m while coming in hot, then popping a chute a few seconds later.  Is this allowed (I also took off vertially)?  Had to run the engine a little in forward mode again to reduce the fall rate so the legs wouldn't explode on impact, even with the big chute. 

Lz1LaoU.png

 It's flat on top cuz the nosecone is a chute.  One Goliath attached radially so it's intake still functions.  The Goliath is attached to the lower Service Bay which houses 16 small radiators to keep them out of the wind.  The cockpit also needed cooling so it has its own Service Bay with 16 little radiators.

 Add me to the listing.  This is the best I got for dessert landing.

 

Edited by klond

Share this post


Link to post
Share on other sites

Attempted design: now with He-100-style wing radiators but using lava instead of water!

nQrJIlH.png

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.