Best Sim Results, OpenRocket or RockSim?

I'd like to know how people are finding out if OpenRocket Sims or RockSim Sims are more accurate. I'm desinging a rocket for a First Nations Launch Competition and the sims will be very important.

Both OpenRocket and RockSim are accurate if you put in the correct data. The leading cause of getting inaccurate results is not measuring your parts individually and relying on an inaccurate model for the simulation. The key to accurate results is to input the mass of all your components individually, measuring their position on the rocket, and then inputting into the sim. You can then use a string to find the center of gravity and measure the mass of the rocket together, ensuring that it matches the sim and if not, make sure to adjust accordingly. Another important aspect is looking at the atmospheric conditions you are using in your simulation as it can noticeably affect the outcome. Things such as wind speed, launch angle, atmospheric pressure, etc can change the trajectory of the launch and therefore affect the apogee.

The best idea would be to make the initial simulation in whichever program that you want (I personally use OpenRocket), make sure that it is accurate to the model itself and launch it with an altimeter onboard. You can then use those results to further tune your simulation, I have seen people get within a few dozen feet of the simulation results.

From my observations and comparisons between the two programs and the resulting launches, I find both can be quite accurate. However, as Ben mentioned, your sim will only be as accurate as your initial data and the prevailing conditions at the time of the launch.

I use OpenRocket mostly, but RockSim has some very nice features, such as the flight visualisation, which I find very useful.

Depends how fast you want to go. I’d use OR and RASAero II for serious flights.

Greg Furtman said:

I'd like to know how people are finding out if OpenRocket Sims or RockSim Sims are more accurate. I'm desinging a rocket for a First Nations Launch Competition and the sims will be very important.

Click to expand...

$$/foot, OR wins every time.

Seriously, the two are very similar in estimations, in that both tend to over-estimate the altitude by somewhere between 10-15%. Though that can also be that I under-guess-estimate the wind speeds (at various altitudes), and over-estimate the smoothness of my paint.

I've used both, and settled on OR because it does not require me to manage licenses between various computers, and because I can run its Java code on my windows, Apple, and Lunix/android laptops. I also like the OR user interface a bit more.

Try both, see which one floats your boat!