High Speed Recovery Device Deployment

[engincan577]

Hi
I have two questions about openrocket simulation. Are these graphs looking normal for a medium altitude rocket and my other question is about high speed device deployment system I could not decrease this speed under 20m/s. How can I solve?

 

[Handeman]

I'm not sure what you mean by "high speed device deployment system I could not decrease this speed under 20m/s." Most rockets fall on a drogue about 30m/s. If you're flying drogueless and it goes ballistic with the upper section pulling the fin can straight down, that can get to or exceed 40m/s Deploying the main at those speeds should not be an issue at all with a well constructed parachute. Zippering the tubes would be a higher concern for me.

Skydivers routinely deploy their chutes at about 55m/s so our main deployments in a drogue controlled decent is relatively slow with reduced loading on the chutes.

 

[waltr]

The graphs look normal. I like to also plot the vertical velocity.
OR has the 20m/s limit built in and gives that warning if vertical velocity exceeds this limit when the MAIN chute is deployed.
If you are doing DD and plan for higher decent speed on the drogue then simply Ignore the warning and study the graphs.

To get rid of the warning the Drogue can be made larger for a slower descent. Try it to see the warning go away. Then go back to your smaller drogue and ignore the warning.

 

[engincan577]

I'm not sure what you mean by "high speed device deployment system I could not decrease this speed under 20m/s." Most rockets fall on a drogue about 30m/s. If you're flying drogueless and it goes ballistic with the upper section pulling the fin can straight down, that can get to or exceed 40m/s Deploying the main at those speeds should not be an issue at all with a well constructed parachute. Zippering the tubes would be a higher concern for me.

Skydivers routinely deploy their chutes at about 55m/s so our main deployments in a drogue controlled decent is relatively slow with reduced loading on the chutes.

If device deployment system has more than 20m/s, openrocket gives a warning and its annoying thats why i want to solve this problem but i dont know is it necessary or not.

 

[Steve Shannon]

It’s not.

If device deployment system has more than 20m/s, openrocket gives a warning and its annoying thats why i want to solve this problem but i dont know is it necessary or not.

It is not necessary. Ignore the warning.

 

[engincan577]

It’s not.
It is not necessary. Ignore the warning.

Thank you for the information