Matching a curve in OR?

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

K'Tesh

.....OpenRocket's ..... "Chuck Norris"
TRF Supporter
Joined
Mar 27, 2013
Messages
22,448
Reaction score
14,747
Ok, I've got a drawing of a nosecone, and I can't share it.

I'm trying to match the curve of it in OR. Imagine it this way... If the back end of the shoulder is vertical (at the 12 O'clock position), and the nosecone is pointed towards the left, the curve I want to get would be based on a radius of 15" for a distance of 4". Mind you, this is not the dimensions of the actual nosecone, but should get me the information I need to do what I need.

I found this on wikipedia... which is basically the same thing (different dimensions though), just rotated counter clockwise to the 6 O'clock position.


285px-Secant_ogive.svg.png

A secant ogive of sharpness {\displaystyle E=120/100=1.2}
4d5df916b163a56e197b71509390fd023908e478


Thanks!
Jim

I have asked the developers for a way to import nosecone shapes like a freeform fin
 
Last edited:
OpenRocket will not simulate aerodynamic performance of a free-form cone, so what is the point?

It's not just used for aerodynamic simulations, there are people (e.g. myself) who use it as a development tool. Besides, it could allow for better simulations if it can handle freeform cones as not everything is a straightforward simple curve.

Oh, and as far as feedback from the developer team... the one I like best is:

[FONT=wf_segoe-ui_normal]I have been looking into importing a profile curve for nose cones for the last week. Also adding spherical tips to existing generated nosecones. I may have a prototype by the end of the week.[/FONT]
 
Last edited:
I have a good idea where the code needs to be modified to support user defined curves, while I am in there I also want to implement spherical nose cone tips. I have the solution for the two equations worked out for Ogive curves and should be similar for the rest.

The end of the week might be optimistic, since I just realized that today is Thursday.

My implementation will still end up with an axisymmetric nosecone.
 
Last edited:
Back
Top