Halting simulation in OpenRocket

Hi All

My first visit here, and I have a question about OpenRocket I wondered if anyone could help with.

I am doing a (theoretical only) project - looking at multi-staging and getting outside the atmosphere. If I get my design good enough the rocket can go to 100s of kilometeres, but because I cannot find a way to stop the simulation, it just carries on running till the computer runs out of memory and crashes. In RockSim you can stop the simulation at a particular time, but being a skinflint I don't want to pay if I don't need to - so is there a way to halt the simulation after a certain time, altitude or event etc

Yes. After you hit "Start Simulation", the box that pops up showing the status of the sim has a small cancel button. Hit that to cancel the sim.

I think this is what you are asking.

OK that works - sort of. It stops the Sim I am running, but OR continually updates its prediction calculating Apogee, max vel and Max accel and displays them in the bottom left corner of the design window - so my sims run very slowly and I get frequent memory full errors

Can you post your simulation so we can see what you are doing?

To try to replicate your problem... I simulated a 6.5" diameter - 3 stage rocket with "O" motors to get maximum altitude.

My simulation runs for 2 seconds, and stops on it's own, with no memory errors - and shows 150 KM altitude.

View attachment Opt3_S3.engView attachment Opt3_S2.engView attachment Opt3_S1.engView attachment opt 4 stage.orkView attachment Opt5_S0.eng

I (think) I have attached the ork file and the 4 motor files, so you can see what is happening, there will be a "calculating" message in the bottom left corner from as soon as the files are loaded.

Rocketian said:

OK that works - sort of. It stops the Sim I am running, but OR continually updates its prediction calculating Apogee, max vel and Max accel and displays them in the bottom left corner of the design window - so my sims run very slowly and I get frequent memory full errors

Click to expand...

I kinda have the same problem. The more I run/edit/run a simuation, the slower and slower it executes. There seems to be some memory issues in the code.

Buckeye said:

I kinda have the same problem. The more I run/edit/run a simuation, the slower and slower it executes. There seems to be some memory issues in the code.

Click to expand...

When this happens to me, I simply save, close and re-start. Works great after that.

Rocketian -

I was able to run your simulation... with the same result - out of memory.

It should be noted that this happened well past escape velocity and at several hundred miles of altitude.

It occurs to me that you are just coasting in space and the sim will continue indefinitely at this point.

The motors you are using probably have enough thrust to put a man on the moon, or beyond! :y:

I did get a bit better performance by properly setting each stage to ignite at previous stage burnout, rather than "automatic".

Then I removed the top three motors, and added enough nose weight to get stable. - Now launching your rocket with just the "0" stage motor - the flight resembled Alan Shepard's Mercury Friendship 7 flight. A nice parabolic flight into outer space reaching an altitude of about 170 km and falling back to the ground.

-in short, your problem is caused by trying to simulate a rocket far outside the "model rocket" parameters for which OpenRocket was designed.

If you want to get out-of-the-atmosphere, and fall back to earth >>> you need to use a less powerful rocket.

FYI, since I think part of the OP's original problem wasn't so much the simulation pane but the ongoing basic simulation data reported in the lower-left corner of the window, at least with the new v15.03 (maybe it was there before), there's a checkbox in Preferences (under the Design tab) called "Update estimated flight parameters in design window". If you uncheck this (may need to close and re-open your rocket design) that should turn off this mini-sim data so it won't always be computing the result for an unusual design. Now when you actually try to simulate the design you'll be exposed to the same issues, but it at least wouldn't affect experimenting with the design.

AlfaBrewer said:

When this happens to me, I simply save, close and re-start. Works great after that.

Click to expand...

Not a very elegant solution.