Jump to content

Talk:Nose cone design

Page contents not supported in other languages.
From Wikipedia, the free encyclopedia

Why not merge this article with the Nose cone article?[edit]

I split the article from the nose cone article because it really focuses on the math involved during nose cone design. Lots of articles use seperate sections for this kind of thing. Ruleke 09:29, 2 January 2006 (UTC)[reply]

Copyright question[edit]

This page appears to be largely a direct copy of the following article, copyrighted in 1996: http://projetosulfos.if.sc.usp.br/artigos/NoseCone_EQN2.PDF - which is even listed in the references. Is there permission to use this? If not, I will consider marking as a copyright violation. --Knotnic 19:57, 12 June 2006 (UTC)[reply]

Please see http://myweb.cableone.net/cjcrowell/VCPMAIN.htm
This is Mr Crowell's site where he publishes the article stating everything on the site is freeware.
If you want
  , I can get an email from him, not sure where to post it or what the procedure is. --Ruleke 09:26, 13 June 2006 (UTC)[reply]
I have verified by email with Mr Crowell that the work is in the public domain. --Ruleke 11:31, 14 June 2006 (UTC)[reply]
Great - thanks for clarifying.--Knotnic 15:58, 14 June 2006 (UTC)[reply]

Create a comparative table?[edit]

The article is interesting but its not easy to discern which designs work best in what situations. Perhaps it needs a table at the bottom comparing the various designs and their characteristics.--Hooperbloob 20:41, 18 June 2006 (UTC)[reply]

Thanks for the suggestion. I have started a section for this. It's not an easy comparison though the table I put in place now is a good first guideline. More to come later. Ruleke 15:38, 2 November 2006 (UTC)[reply]

Why is a cone mischosen?[edit]

"A very common nose cone shape is a simple cone. This shape is often chosen for its ease of manufacture, and is also often (mis)chosen for its drag characteristics." Why is a cone mischosen? Does it have more drag than one would normally assume? Banaticus 08:27, 24 July 2006 (UTC)[reply]

The conical shape has a drag coefficient of about 0.5, which is very low. However, the turbulence created with this nose cone when fitted to a rocket causes the total drag coefficient to be the worst of the shapes listed here. Ruleke 08:51, 25 July 2006 (UTC)[reply]
So on subsonic propellor driven aircraft, a sharp conical nose is a better choice or would it still be better to go with a more rounded nose cone? 22:18, 27 July 2006 (UTC)

I realize this is about 'nose cones,' but with regard to kinetic weapons like bullets, and penetrating weapons like certain bombs, the shape of the nose may be chosen for penetation and shaping of the impact, the impact's explosion, etc. as well as aeordynamics. Not sure if that is pertinent, which I why I like writing in the 'discussion' first. Paulc206 08:38, 19 March 2007 (UTC)[reply]

The Von Karman shape is not explained[edit]

Just referred to in the table of preferred shapes. -- Egil (talk) 21:47, 2 September 2009 (UTC)[reply]

My fault, it was mentioned, but not obvious for me at a brief glance. I've added a small subchapter to make it more obvious, especially when coming here via the Von Karman ogive link. -- Egil (talk) 05:33, 3 September 2009 (UTC)[reply]


reference link not working.

Secant ogive[edit]

The last formula states that the ogive radius is greater than 2L, but the associated graphic show that L is greater than the ogive radius. In fact, L can approach 2 time the ogive radius, so the formula may have it reversed, in that L must be less than the 2 times the ogive raidus. — Preceding unsigned comment added by (talk) 18:22, 24 February 2013 (UTC)[reply]

Citation needed: "The Haack series nose cones are not perfectly tangent to the body at their base"[edit]

It can be proven mathematically by differentiating y and substituting in x=l. Does this really need a citation? — Preceding unsigned comment added by (talk) 22:58, 23 October 2014 (UTC)[reply]

According to https://en.wikipedia.org/wiki/Sears%E2%80%93Haack_body, the derivative is 0 at x = 1/2, for C = 1/3, contradicting this article. (talk)

The Sears Haack body is a different shape altogether. The statement in the article is mathematically verifiable. Maxwelljets (talk) 18:45, 3 November 2016 (UTC)[reply]

Link misleading[edit]

The first reference mentioned doesn't go to a pdf file as it claims - it opens a website. Could you kindly update this? Yetanotherwriter (talk) 21:57, 17 December 2015 (UTC)[reply]

Parabolic vs parabolic shape[edit]

"The power series includes the shape commonly referred to as a "parabolic" nose cone, but the shape correctly known as a parabolic nose cone is a member of the parabolic series (described above)." This statement is very awkward. Can it be reworded? Also, the "power series" shape isn't particularly blunt, either. The tangent vector at the vertex doesn't look perpendicular to the axis of rotation. Rather, it seems to come to a point like an ogive. SharkD  Talk  03:47, 9 April 2017 (UTC)[reply]

Influence of the general shape[edit]

the performance chart is poorly referenced and doesn't even say what bluntness, vertex angles, and fineness ratios performed poorly, or what the test conditions were, except for mach number. so calling either cones or ogive's inferior is not proved. as a quick calculation, take the vertex half-angle, theta, at the tangency point: then 1/(tan theta) becomes the mach number at which air striking the area forward of the tangency point is forced to compress, but if striking the area aft it is allowed to blast outward at the speed of sound. all noses with the same bluntness and vertex half-angle at this point should perform similarly at this mach number. Waveguy (talk) 04:10, 3 October 2020 (UTC)[reply]

this chart appears in the source document by Gary A. Crowell, as well, and he has extensive references but attributions for the chart are not clear, and i don't know which of these might be online in some form. the reason i believe this needs to be justified is, the tangent ogive nose cone was chosen by SpaceX for their Starship rocket. the chart here lists it as inferior, yet i believe they did their homework to be confident that it would work, including all necessary computational fluid dynamics simulations; if this shape were truly inferior they would either choose something else or be risking a lot to have a retro future look. -- Waveguy (talk) 03:53, 30 October 2020 (UTC)[reply]
ok, found the chart in Chinn fig.3-12, p.27. will dig in and see what extra info can be teased out. meanwhile i updated the attribution for it in the article. -- Waveguy (talk) 05:19, 31 October 2020 (UTC)[reply]