OpenRocket feature request

[McKailas Dad]

Is there any way to have 'presets' for the latitude, longitude, altitude, and launch rod length?

I launch in a few different locations, and seem to lose track of all of those numbers, and always end up having to recheck them online.

Besides, who has a 3.28' rod?


I really like what you all have done in 12.09, but I think this would be an appreciated feature.


Thanks, and keep up the great work!

 

[Reinhard]

Besides, who has a 3.28' rod?

3.28ft = 1m. So it is not an unusual length outside of the US.

Reinhard

 

[CarVac]

I have a request for a feature: drag separation force computation.

Within component analysis for drag, you should be able to place a 'separation point' between two of the items, and have OR automatically compute the drag separation force. That would be simple as taking the drag force on the back half and subtract from that the mass of the back half (obviously, using the burnout mass of the motor) times the acceleration experienced by the whole rocket at that speed.

For example, my Disappearing Act with a spacer tube on a J500 Green has about 368 grams behind the separation point after burnout, decelerates at 30 G's at burnout (at Mach 2), and has a drag force on the back half at that speed of 58% of 195.5 N.

30*9.81*.368 = 108.3 N needed to slow down the aft portion of the rocket, versus the 113.39 N of drag on the back end. Thus, there is 5 N separation force at Mach 2.

Could this be included in the program? It would be a very very useful extension to the 'component analysis' tool.

 

[Peter Olivola]

I think I asked for this once before, but here it is anyway: The option to not specify the motor delay but have the program compute optimum delay. Why? Because, especially with reloads and delay modification tools, it's possible to get close enough to optimum.

 

[kruland]

Hey CarVac.

I've been thinking about something similar and had been working in that part of the code already. I was trying to allow modelling of boosted darts which also may utilize drag separation.

For your application though are you modelling two different stages or simply the separation point between say NC and body tube? Would it be adequate to compute the drag induced separation force over time and allow you to plot it?

Kevin

 

[CarVac]

It would be adequate to compute the drag separation force, but you can't get at the drag coefficients and masses of the subcomponents, and it would be a major pain (the more components you have, the more terms in the equation!).

I was thinking about checking the drag separation of a recovery point to figure out the required friction (since my rocket uses the motor as a coupler, I can't shear pin it), but the same method would work more easily for a staged rocket or a boosted dart, since the respective parts of the two halves are actually logically separated in the design tree.