Help Support RocketryForum by donating using the link above or becoming a Supporting Member.


Results 1 to 5 of 5
  1. #1
    Join Date
    27th March 2013
    Location
    Has Changed
    Posts
    9,163

    Question Matching a curve in OR?

    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.



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

    Thanks!
    Jim

    I have asked the developers for a way to import nosecone shapes like a freeform fin

    Last edited by K'Tesh; 16th February 2017 at 11:56 PM.
    Dreaming of making the rockets I dreamed of as a kid (and then some).


    NAR L1 Cert flight: Sheridan, Oregon, USA. Sept. 19, 2015. Flew Deep Space OFFl on an I357T-14A Blue Thunder

  2. #2
    Join Date
    6th September 2009
    Posts
    1,493
    Quote Originally Posted by K'Tesh View Post

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


  3. #3
    Join Date
    27th March 2013
    Location
    Has Changed
    Posts
    9,163
    Quote Originally Posted by Buckeye View Post
    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:

    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.
    Last edited by K'Tesh; 17th February 2017 at 02:40 AM.
    Dreaming of making the rockets I dreamed of as a kid (and then some).


    NAR L1 Cert flight: Sheridan, Oregon, USA. Sept. 19, 2015. Flew Deep Space OFFl on an I357T-14A Blue Thunder

  4. #4
    Join Date
    21st April 2010
    Location
    So central WI, USA
    Posts
    5,318
    doing up a Cherokee D model Jim?
    Rex
    L2-competitor 3, AT J350W, 8/27/2016, Bong, 2557'
    my youtube channel http://www.youtube.com/channel/UC0gB...?feature=watch

  5. #5
    Join Date
    23rd February 2014
    Location
    Eastern Shore, MD
    Posts
    262
    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 by djkingsley; 17th February 2017 at 03:29 AM. Reason: added axisymmetric note
    Dennis Kingsley
    NAR #97251, MDRA #064
    L1 - Madcow Torrent
    L2 - Madcow Sensor
    L3 - Extended Madcow Stinger

Similar Threads

  1. Color Matching
    By adayzdone in forum The Watering Hole
    Replies: 23
    Last Post: 20th September 2013, 12:21 AM
  2. I hate Paint Matching
    By awseiger in forum Techniques
    Replies: 8
    Last Post: 10th August 2012, 02:25 AM
  3. Matching Parachute Size to Weight
    By Alby in forum Recovery
    Replies: 9
    Last Post: 25th October 2011, 12:11 AM
  4. Matching igniters for clusters
    By Rocketeer Gator in forum Beginners & Educational Programs
    Replies: 14
    Last Post: 4th October 2010, 05:20 PM
  5. Non-Matching Fins and Performance
    By Necromancer in forum High Power Rocketry (HPR)
    Replies: 17
    Last Post: 23rd July 2008, 02:59 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •