OpenRocket Descent Rate - Two Parachutes, Separate Sections

[Cherokee]

This years TARC requires that the rocket come down as separate sections with the payload being the timed section. Can anyone tell me if OpenRocket can be set up to simulate the payload section descent rate separate from the sustainer section? I tried setting up the rocket with two stages with a parachute for each stage and no motor for the payload.

 

[BEC]

Bump - Trying again.

I'm working with a couple of TARC teams for which the answer to Cherokee's question would be REALLY useful. One team has arrived at the same approach that Cherokee describes, and by playing with the "separation" options under "stages" on the configurations tab we can get two different descent curves in a simulation plot....but it isn't entirely clear that what we are seeing is what we need.

Any OR power users out there who might weigh on on this now?

 

[K'Tesh]

This years TARC requires that the rocket come down as separate sections with the payload being the timed section. Can anyone tell me if OpenRocket can be set up to simulate the payload section descent rate separate from the sustainer section? I tried setting up the rocket with two stages with a parachute for each stage and no motor for the payload.

While I can't help you on the OR simulation of two descent rates, I seem to remember that RocSim has a way to do it... Lemme look...

[video=youtube;Q7DM1ls3PpY]https://www.youtube.com/watch?v=Q7DM1ls3PpY[/video]

 

[Travis]

I am working on the same thing! I am planning on having my students do most of the modeling in Open Rocket to start with as I am new to TARC and teaching rocketry. Once we do some trials just seeing how close to altitude we are, I will possibly buy rocsim to have students model the different descent rates. Any advice would be greatly appreciated!

 

[boatgeek]

I believe that it is accurate to create an OpenRocket model with two stages. The eggs go in the sustainer section with two (or more) chutes and no motor. The booster is just your fin can plus whatever other recovery you were planning for that. You have to play with the stage separation and parachute options to get the stages to separate and the sustainer parachutes to "deploy" when the ejection charge on the motor fires. You'll also need to play with the location of the sustainer chutes so that the CG is modeled properly. The plot should show the two pieces coming down separately.