Musings on mk1 nose cones

[Foxster]

For some of us pushing the envelope, the choice of mk1 nosecone matters. For instance, it can make the difference whether your Eve craft makes orbit or not.

So, I've started a little testing to see which of the nose cone variants seems "best" in 1.0.5.

What I have so far was found using this simple rocket lifting to a 100km Kerbin orbit with a different central nose cone (the other nose cones on the side tanks stayed the same each time)...

[IMG]http://i.imgur.com/BYezrXI.jpg[/IMG]

I flew it with MJ and used the measure of how much dv was left after MJ handed over control on reaching a 100km orbit. Repeated twice more and results averaged. This measure should take account of drag and mass, expecting both to increase the dv used.

Here's the results so far:

Advanced Nose Cone - Type A: 1820 m/s. This nose cone got the hottest, it was close to heatploding on the way up. Perhaps due to having a max temp of 2000°.
Adjustable Ramp Intake: 1833.
Shock Cone: 1788. This would likely have been the champion in 1.0.4 but it's mass was increased a lot in 1.0.5.
Circular Intake: 1838. The best score. However, it does have a low max temp of just 1900° and came really close to heatploding.
Aerodynamic Nose Cone: 1835.
FL-A10 Adapter+Small Nose Cone: 1823. Also didn't look good temperature-wise.

So, the nose cone I am going to declare as the surprise winner in this particular test is the humble Aerodynamic Nose Cone!

[IMG]http://i.imgur.com/PIVJJdk.jpg[/IMG]

It has the lowest mass, pretty low drag and yet a high max temp of 2400°. Meaning it is pretty darned good.

[Foxster]

Ok. Let's repeat that but swap out all 5 nose cones each time. Not sure why didn't just do that the first time but never mind, it's all good...

[COLOR=#3E3E3E]Advanced Nose Cone - Type A: 1820[/COLOR]
[COLOR=#3E3E3E]Adjustable Ramp Intake: 1820[/COLOR]
[COLOR=#3E3E3E]Shock Cone: 1771[/COLOR]
[COLOR=#3E3E3E]Circular Intake: 1828 [/COLOR]
[COLOR=#3E3E3E]Aerodynamic Nose Cone: 1799[/COLOR]
[COLOR=#3e3e3e]FL-A10 Adapter+Small Nose Cone: 1806[/COLOR]

[COLOR=#3e3e3e]This has mixed things up compared to the last test. The aerodynamic nose cone did less well this time, probably because it is draggier and it's lower mass doesn't compensate.

The highest dv left was achieved with the Circular Intake. It has low mass and low drag. If temperature is not an issue then it's probably the one to go with. However, with a max temperature of just 1900°, it is going fail you at some point.

The worst was the shock cone. Its increased mass in 1.0.5 (why ever did they do that??) has left it looking poor here.

My Editor's Recommendation is the [B]Adjustable Ramp Intake[/B].

[/COLOR][IMG]http://i.imgur.com/LjG2UMn.jpg[/IMG]

It has low mass, low drag and high temperature tolerance.

[rdwulfe]

Great info here, sir. Thank you.

[TMS]

Were the intakes open or closed?

[Foxster]

[quote name='TMS']Were the intakes open or closed?[/QUOTE]Tried it with a couple of them and it made no difference.

[RocketPropelledGiraffe]

Did you compare to using no cones at all - You save some mass and increase drag, depending on the launch profile and the atmosphere it can be a good option?
It's certainly not helping on Eve, and propably the better option on Duna. Do you have data for Kerbin or Laythe?

[cantab]

Use the rotate gizmo to turn the nosecones so they point backwards, clipped inside the tank. You'll get even better performance. Don't you just [I]love[/I] Squad's idea of aerodynamics?

[Foxster]

[quote name='cantab']Use the rotate gizmo to turn the nosecones so they point backwards, clipped inside the tank. You'll get even better performance. Don't you just [I]love[/I] Squad's idea of aerodynamics?[/QUOTE]Well, yes, I could do that and some of my craft do use that but I was trying to keep this non-exploitive, as some might term it.

[Gaarst]

What about advanced nosecones type-B ?
I remember seeing somewhere that their dragbox was identical to the type-As', but I'm not really sure.
Do they offer any advantages compared to the type-A, especially concerning airflow around radial boosters, other than being prettier ?

[egoego]

I did a similar test a few days ago, but with a different (simpler) setup:
RC-001S probe core, Z-1K power for the sas and core and weight for balance, SAS near CoM, RT-5 booster.
I would just enable stability and launch this thing, then wait until it falls down again, hit F3 and look for greatest hight achieved.

This gave me the following little table (1st column: whats on top, 2nd column: how high did this thing fly in meters)

AE-FF2 Airstream Protective Shell (2.5m) (min high) 2889
AE-FF2 Airstream Protective Shell (2.5m) (max high) 4065
RC-001S Remote Guidance Unit (test stack without cone) 5403
Heat Shield (1.25m) 5682
Z-1k Rechargeable Battery Bank (test stack without cone, reordered) 5736
AE-FF1 Airstream Protective Shell (1.25m) (min high) 5851
Clamp-O-Tron Shielded Docking Port 6792
M700 Survey Scanner 8144
Mk1 Command Pod + Mk16 Parachute (on top of test stack) 8283
Aerodynamic Nose Cone 8896
Mk1 Command Pod + Small Nose Cone (on top of test stack) 9210
Mk1 Command Pod + Mk16 Parachute (instead of battery and probe core) 10321
Mk1 Command Pod + Small Nose Cone (instead of battery and probe core) 12207
Advanced Nose Cone - Type A 13896
Shock Cone Intake (open) 14717
Shock Cone Intake (closed) 14717
Tail Connector A 15998
AE-FF1 Airstream Protective Shell (1.25m) (max high) 17601

Intakes had no difference between open and closed, did this test twice. Is this a bug? Edited November 21, 2015 by egoego

[Hcube]

We should do a few statistic tests in order to see wether the differences are significant. You did the experiment only 2 times for each nosecone and made the average, so provided there was a big enough difference between each 2, the difference might be insignificant !

EDIT : tried some numbers, and with only 2 measurementd for each nosecone, unless each of the two results are very very close (like 2m/s of difference), the difference between Shock cone and Circular intake is non-significant with a reasonable risk...
With only two measurements it's never going to get amazing precision ^^ Edited November 21, 2015 by Hcube

[fourfa]

I suspect the drag vs weight tradeoff is different on Eve vs Kerbin, if that's still your primary concern. I've even found that using hyperedit to change the planetary and atmospheric conditions on Kerbin to be the same as Eve, doesn't test the same as actually launching from Eve. Pain in the butt though

[Foxster]

[quote name='fourfa']I suspect the drag vs weight tradeoff is different on Eve vs Kerbin, if that's still your primary concern. I've even found that using hyperedit to change the planetary and atmospheric conditions on Kerbin to be the same as Eve, doesn't test the same as actually launching from Eve. Pain in the butt though[/QUOTE]It wasn't really the primary driver behind the tests but it is a factor. I have repeated it for a couple of the nosecones on Eve but then I had to go drink beer for a while. Dang, don't you hate having to do that?

[problemecium]

Well if I'm taking anything from this thread, it's pleasure that they buffed the Aerodynamic Nose Cone in some fashion. The poor thing seemed all but outmoded after the advanced nosecones showed up.

[Foxster]

[quote name='parameciumkid']Well if I'm taking anything from this thread, it's pleasure that they buffed the Aerodynamic Nose Cone in some fashion. The poor thing seemed all but outmoded after the advanced nosecones showed up.[/QUOTE]I think it is a bit of a shame, as well being slightly odd, that none of the actual nose cones are the best nose cones.

[peachoftree]

Is there similar data for FAR? I would assume an advanced nosecone type A in the center + advanced nosecone type B on the outside would be the best but I could be wrong.