Consulting work for Open Rocket or Rocksim expertise

[Mustang67]

Hello,

Anyone have expertise with large rocket simulations in either Open Rocket or Rocksim?

I have an 8 inch kit and a large O motor I would like some assistance with in building it in either program and running sims. Happy to pay for the help.

If you are interested, have the expertise then send me a PM.

Thx in advance.

-Jerry

 

[NTP2]

come forth ohh mighty one, I summon yee (@neil_w)

 

[neil_w]

I'm not sure there's anything particularly special about simulating a large rocket vs. a smaller one, just scale it up. You can use the built-in dual deploy example rocket as a starting point if you like.

The harder point, presumably, is *building* a beast like that. But entering the design into OR or Rocksim should be relatively straightforward.

 

[Mustang67]

It is a Jumbo Dark Star, extended a few feet and with a 152mm motor. It's the motor I want to be sure get's simed right as it will most likely break Mach. The booster is built and just tested the EX O motor and have the data for it.

 

[neil_w]

Again, I'm not sure that there's anything special there. If you want to post the file and get feedback here that's fine. There are plenty of L3 rocketeers here who should be able to look it over.

 

[Mustang67]

Fair enough and thank you.

 

[dvdsnyd]

With regards to the Rocksim/OpenRocket sim. There isn't anything more you should have to account for that you aren't on smaller rockets/flights.
Biggest thing is your CP/CG relationship as always.

Utmost care should also be taken in your motor file, ensuring that your thrust curve and parameters such as mass of propellant/case are all correct, to ensure that you get an accurate sim.

Not trying to gloss over your request, by all means, if you have a specific question with regards to importing motor files, building motor files, or specific design question about the rocket or how to do something within the sim, please ask away.

Dave

 

[Mustang67]

With regards to the Rocksim/OpenRocket sim. There isn't anything more you should have to account for that you aren't on smaller rockets/flights.
Biggest thing is your CP/CG relationship as always.

Utmost care should also be taken in your motor file, ensuring that your thrust curve and parameters such as mass of propellant/case are all correct, to ensure that you get an accurate sim.

Not trying to gloss over your request, by all means, if you have a specific question with regards to importing motor files, building motor files, or specific design question about the rocket or how to do something within the sim, please ask away.

Dave

All good and appreciate the feedback. Its simply due to the size of the motor I want to make sure I have this right, It's a 38K newton motor with a 2.9 burn. And I don't have the Rocksim/Open Rocket experience that I would like to have for this specific flight. I will get it going and post any questions that I have. Appreciate all the feedback!

 

[JoePfeiffer]

As others have said, there's nothing about size that requires anything special from a simulation. The rocket in the picture was simmed in OR with no particular extra work.

 

[thzero]

As others have said, there's nothing about size that requires anything special from a simulation. The rocket in the picture was simmed in OR with no particular extra work.

Looks kinda small ...

 

[Mustang67]

As others have said, there's nothing about size that requires anything special from a simulation. The rocket in the picture was simmed in OR with no particular extra work.
View attachment 641428

So in a rocket that size hitting Mach 1 or Mach 2, for a short period of time, RAS is not needed? And RS or OR will work just fine in predicting flight data?

 

[neil_w]

If you're going up around Mach 2 then yeah, double checking the model through RAS Aero is a good idea. Just export the model from OR.

 

[JoePfeiffer]

So in a rocket that size hitting Mach 1 or Mach 2, for a short period of time, RAS is not needed? And RS or OR will work just fine in predicting flight data?

Size and speed are not the same thing. If you're getting around Mach 1 for a short period of time, it should be fine. If you're getting near Mach 2 I'd want to also run RASAero -- and I'd say the same thing if your rocket was much, much smaller. Note that OR can export RASAero files.

 

[Mustang67]

Likely close to Mach 2 due to the motor which is why I reached out. I have some assistance now and thank you,

 

[OzHybrid]

As others have said, there's nothing about size that requires anything special from a simulation. The rocket in the picture was simmed in OR with no particular extra work.
View attachment 641428

All that denim would have been difficult to simulate....

 

[OzHybrid]

The process is the same.
Create a thrustcurve for your motor if it's not a commercial motor.
Roughly design the rocket in OR and sim to make sure your ballpark numbers are ok.
Refine design and weights and Sim as you go along with the design
Correct design and weights to finished component weight as you know it and override those masses.
If you're going over Mach, run a RASAero sim. ( there was an OR issue exporting data into RASAero so best to recreate it from scratch in RASAero)
Check for Fin Flutter limits.
Figure out how you'll get to the launch site.
Pick a good day and launch it with any launch paperwork required.
Good luck with the project.