#1 Add NAR and CNES validation properties

open
nobody
Other (7)
5
2009-09-21
2009-09-21
Fred_76
No

A new page should be added to the analysis menu. This page should check the acceptance criteria defined by the NAR and the CNES.

NAR criteria (see http://www.nar.org/pdf/launchsafe.pdf\) :
1. Distance between mass center and center of pressure at 15° AOA between 1 and 3 calibers
2a. speed when the rocket leaves the launchpad greater than 4 times the wind
2b. if wind unknown or if calculation of speed in 2a. above is not possible, limit the thrust to weight ratio to 6:1 or greater (7:1, 8:1 ...)
3. max wind at laucnh if 20 mph (abt 35 km/h)

CNES (french space agency) criteria (see http://www.planete-sciences.org/espace/basedoc/Vol_de_la_fus%C3%A9e,_stabilit%C3%A9_et_trajectographie , page 15) :

They define the static margin (=MS) being the ratio of the distance betwen the center of mass and the center of pressure, by the rocket diameter (caliber).
A. for micro-rockets :
1. Cna between 15 and 30
2. MS between 1 and 3
3. Finesse ratio (length/caliber) between 10 and 30

B. For mini-rockets :
1. Cna between 15 and 30
2. MS between 1.5 and 6
3. Finesse ratio (length/caliber) between 10 and 20
4. Cna x MS between 30 and 100
5. Speed of rocket at launch ramp exit > 18 m/s

C. For HPR
1. Cna between 15 and 40
2. MS between 2 and 6
3. Finesse ratio (length/caliber) between 10 and 35
4. Cna x MS between 40 and 100
5. Speed of rocket at launch ramp exit > 20 m/s

Other criteria may exist from other rocket associations and should be added in Openrocket.

Best regards

Fred

Discussion

  • Sampo Niskanen
    Sampo Niskanen
    2009-09-21

    That's a good suggestion. I'll add it to my TODO list, though there are many more acute things to implement as well.