Open Rocket Wishlist

Discussion in 'Rocketry Electronics and Software' started by SRP Crew, May 16, 2012.

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  1. May 16, 2012 #1

    SRP Crew

    SRP Crew

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    Hi everyone,
    There's still so many more things Open Rocket could add/tweak to improve an already pretty good simulator. So, if you use it like I do, but wish they could do improvements, maybe we could ask nicely for them.

    Here's some of my own suggestions to get the ball rolling:

    *Under the File pulldown menu: Provide at least a few of your last/recent project choices.
    *During motor selection, once you have chosen a motor, and run the sim., then you choose another motor, could we have the selection default on the last motor picked. (saves us from scrolling down the menu all the time).
    *Have the 3d view include layers and graphic textures. A nice touch and Just asking.
    *Why is it when you open a file, do what you need to do, then goto File, then Close, the editor disappears. But if you Open another file while you have a file already running, the old one is still running in another window.
    *How about a tube fin option with the proper math/aerodynamics.

    There's so many other ideas so please chime in.
    I'm sure the programmers would like to hear from you.

    Cheers
    the SRP Crew
     
  2. May 17, 2012 #2

    o1d_dude

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    Ability to handle tube fin rockets.
     
  3. May 17, 2012 #3

    Salvage-1

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    .. and ringtail
     
  4. May 17, 2012 #4

    kruland

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    Hi all,

    The biggest thing holding up implementation of tube fins, ring fins, and pods is the mathematics to compute the aerodynamic effects of these. Anybody have references to the cd and lift effects of these?

    Kevin
     
  5. May 17, 2012 #5

    o1d_dude

    o1d_dude

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    In theory a standard six tube fin rocket can be simulated by using enough fins with an area equal to the same area as the tube fins. I believe the theory states 18 or 19 fins are equivalent to six tube fins.

    If you search online there are a couple of methods of accomplishing this with RockSim.
     
  6. May 17, 2012 #6

    jpummil

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    I've pondered this for awhile...guess I should stop thinking and start researching properly :confused:

    When I built my slightly upscale Super Neon XL, I did precisely what Kit suggested...used 3 regular fins per tube fin...and the sims and actual flight seemed to correlate acceptably. However, it just doesn't seem logical as the balsa fins would have much more area than the tube fin they were simulating UNLESS one was very careful to calculate in advance the amount of frontal area creating drag as well as the aggregate surface area of the sides of the fins. So, one would need the thickness of the tubing as well as the total area "doing work" of each tube fin (100% of the interior + about 1/2 of the external to account for bonding to BT as well as adjoining tube fins).
     
  7. May 17, 2012 #7

    El Cheapo

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    Tube fins for sure. I've used three fins per tube fin in OR it show an error but the sim does correlate to an identical Rocksim file.
     
  8. May 17, 2012 #8

    Rex R

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    the ability to set the 'default launch conditions' to match the local field conditions would be nice. that way one wouldn't have to set them for every sim. thanks
    rex
     
    Last edited: May 17, 2012
  9. May 17, 2012 #9

    DAllen

    DAllen

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    Hahaha...I was just scrolling to the bottom of this thread to post exactly that. You beat me to it.
     
  10. May 17, 2012 #10

    bytesiz

    bytesiz

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    +1 and a quick way to handle this might be to just create a "copy simulation" button. That way you define the first simulation, then subsquent siumulations could be based on the first and we could just tweak whatever we want.
     
  11. May 18, 2012 #11

    Sampo

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    Hi,

    My plan is to store the user-set launch conditions as default that will be used the next time a new simulation is created. Once I have time...

    As for duplicating simulations, you can just select a simulation and copy-paste it.

    Cheers,
    Sampo N.
     
  12. May 18, 2012 #12

    DAllen

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    Are you freaking serious? It's that simple?

    *facepalm*
     
  13. May 18, 2012 #13

    bytesiz

    bytesiz

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    Well, heck, that is too easy. I learned something today. That meets my needs perfectly.
     
    Last edited: May 18, 2012
  14. May 18, 2012 #14

    Aksrockets

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    Here is my personal wishlist:

    A database of rocket components, similar to rocksim, this can be customizable.
    simulating multiple flights at the same time
    A quicker way of selecting motors and flying.
    A 3d thing where you can design custom paint schemes.
    Using pods

    Thanks, Sampo for all the hard work you do. Openrocket is my most used tool in rocketry.

    Alex
     
  15. May 18, 2012 #15

    jpummil

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    Tube fins would be useful to many...
    I always kinda wanted an "overlay" feature where you could have a baseline model inactive and have the rocket you're modding more visible and operable.
    Sampo, whatever happened to YOUR wish of integrated CFD in OR? Has anyone attempted to find a rudimentary Java based 2D CFD code to add kind of like your Optimization option? Can 'o worms and REALLY bad results if you do it wrong, but....
     
  16. May 19, 2012 #16

    Sampo

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    Hi,

    - Component database is being worked on by Kevin Ruland, and is coming along nicely.
    - If by simulating you mean running all of the defined simulations, you can select all of the simulations (click the first one, then shift-click the last one, or ctrl-click the ones you want) and just hit run.
    - Have you used the "Edit motor configurations" dialog (under the Motor configurations dropdown)? Any ideas for an easier UI for motor selection are welcome.
    - 3D is also being worked on by Bill Kuker, and it's looking awesome. There's already a very cool "3D schematic" view. Not sure will the first release contain a live-like 3D view, but it's progressing.
    - Pods would be quite a bit of work to support. I've got some ideas on how the aerodynamic could be made to work, but it would need quite a bit of free time to implement...


    Tube fins similarly need more aerodynamical work. I'm not completely satisfied by the "three-fins-equal-tube-fin" approximation, it sound like hand-waving to me. :) I've been meaning to try to contact Larry Brand who I've understood has done quite a bit of research into the subject.

    Can you explain the overlay feature more? I'm not sure I understand what you're suggesting.

    As for CFD, I've practically given up hope of implementing it myself. Would need someone more skilled in aerodynamics and CFD codes than I am. :)

    Cheers,
    Sampo N.
     
  17. May 20, 2012 #17

    kruland

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    I'll add one:

    Simulating high power motors loaded in "different" cases. With the introduction of the adapter systems for AeroTech and CTI, the simple motor model is no longer completely accurate. The mass of the motor with case is higher. As an aside, it would be nice to get the Thrustcurve's case info field sorted out. It has lots of weird data in it.

    Kevin
     
  18. May 20, 2012 #18

    Peter Olivola

    Peter Olivola

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    A classic case of garbage in/garbage out. Most thrust curves are from sources like NAR S&T, Tripoli motor testing, etc. The problem isn't OR, it's the high noise level associated with measuring motor performance. That's why obsessing over small differences in motor performance is such a waste of time. Thrust curve data is a rough approximation at best.

     
  19. May 20, 2012 #19

    CarVac

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    He means the case info field, which has to be entered manually; that doesn't come from the motor testing data.
     
  20. May 20, 2012 #20

    kruland

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    That's exactly right. Case Info does not come from the eng/rasp file itself. Although I have found some files out there from "reputable s&t organizations" which have obvious mistakes like saying that a Quest B is 19mm instead of 18mm. etc.

     
  21. May 21, 2012 #21

    donperry

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    Hey Sampo. I have a lil concern with OR. I don't know if I'm doing something wrong but when I create a rocket with NO parachute and fly it, the flight simulation says the rocket (Which would apogee in 14 seconds) takes about 2 minutes to fall back to earth, free fall??! I think something may be wrong here.


    Now for my wishlist:

    • Software pretty good so far, just waiting on the 3D :D
    • Oh, just a little one - Can the CG and weight of the Motor ITSELF be adjusted? The lower portion of my motors are heavy and I have to be compensating for it in the design for correct CP/CG
     
    Last edited: May 21, 2012
  22. May 21, 2012 #22

    jpummil

    jpummil

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    Just attach your .ork file to your post and some of us can take a look at it...
     
  23. May 21, 2012 #23

    Sampo

    Sampo

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    Hi,

    I've noticed a similar problem early on. The rocket is likely rocking back and forth during the descent, causing it to be constantly at an angle of attack and causing excessive drag. Seems like something should be tuned a bit in the aerodynamics.

    Regards,
    Sampo N.
     
  24. May 22, 2012 #24

    donperry

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    Oh, so the simulation probably has a high speed tumbling rocket falling back to earth? That would certainly create some drag.
    Maybe it can be tuned a bit so the rocket would do the lawn dart behavior we normally dread :)

    Just make a simple rocket with a motor, with no chute and try it. Still, I've attached an example ORK file View attachment test_flight.ork
     

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