Apogee volue is not true

[turkkusuroket]

Hi friends I have question. Apogee volue is 3032 m (in simulation screen) but apogee volue is 4700 m (on the screen with the design). Why are these values different?
Thank you...

 

[Voyager1]

Make sure you have the correct motor selected in the Flight Configuration drop-down list on the top right side of the main design screen.

 

[turkkusuroket]

Make sure you have the correct motor selected in the Flight Configuration drop-down list on the top right side of the main design screen.

View attachment 405932

I'm sure ,I chosen correct engine. already ı have just a engine.This problem is continue

 

[markg]

Post your .ORK file so we can take a look

 

[Buckeye]

The value on the screen is just a quick approximation that updates as you modify the geometry design. The value in the simulation tab is the proper, complete simulation.

 

[JMX]

You can use the motor overide feature to input your own values if needed.

 

[Voyager1]

The value on the screen is just a quick approximation that updates as you modify the geometry design. The value in the simulation tab is the proper, complete simulation.

That's correct. However, in most of my sims the difference is usually only a few feet at the most. From my sim presented above the values are:

Sim Value Design Panel Value
748 750
1139 1142
2444 2446
2750 2752

 

[Voyager1]

Better formatting makes it clearer!

 

[Brian24257]

Hello! I'm having the same problem with a two stage high power rocket design. In the design tab it appears at 2450 ft apogee and in the simulation appears 1878 ft. Is there anything that makes that happen?

 

[neil_w]

Darn good question. Mind if I post that file to the developer list?

 

[Brian24257]

Darn good question. Mind if I post that file to the developer list?

Yes, I just wanna find the explanation to this. Been reading the technical report of Open Rocket but it doesn't say anything related to this.

 

[thequick]

Check your engine delay. Maybe it is ejecting before apogee in the simulation and limiting the height

 

[neil_w]

Yes, I just wanna find the explanation to this. Been reading the technical report of Open Rocket but it doesn't say anything related to this.

Looks like it might actually be a bug. Investigation is just starting. Will post back here with any developments.

You can track it yourself here: https://github.com/openrocket/openrocket/issues/671

 

[JoePfeiffer]

I'm afraid you've uncovered a discrepancy in how the rocket is simulated between the design pane and the flight simulations tab. I've spent some time looking at it, and I'm confident the flight simulations tab is more accurate (and there's a way to get rid of the discrepancy in the current development branch, which I'll be implementing tomorrow morning). All current development is aimed at that branch, so I'm afraid the problem will remain in 15.03. So... ignore the estimate in the design pane.

 

[Ronz Rocketz]

The last release was in 2015 so how likely will an update be released?

 

[JoePfeiffer]

We're working on it (and there are more developers putting in more time than there has been in a long while)... hopefully this year...

 

[Ronz Rocketz]

Any chance of allowing fins to be attached to other parts than body tubes like transitions? I would like to sim my V2 and Expedition rockets. Mahalo.

 

[neil_w]

Any chance of allowing fins to be attached to other parts than body tubes like transitions? I would like to sim my V2 and Expedition rockets. Mahalo.

That’s in the next release.

 

[neil_w]

Hello! I'm having the same problem with a two stage high power rocket design. In the design tab it appears at 2450 ft apogee and in the simulation appears 1878 ft. Is there anything that makes that happen?

Here is some important detail regarding your simulation: The rocket, as entered, is grossly underpowered. The sim shows 11 miles per hour off the rod which is way too slow. As a result, the rocket flight is way off vertical. This highly non-optimal flight profile is the biggest contributor to the difference between the two apogee numbers. It revealed a problem in OR, which is good (will be fixed next release). However, you certainly shouldn't fly your rocket like that.

 

[thzero]

Except that OpenRocket hasn't released anything new in years, master and web site is still on OpenRocket 15.03 (2015-03-28). Releasing a fix to the "unstable" branch doesn't really count as most people don't pull github and then compile versions. At some point, unstable needs to be migrated to the master a new version released.

 

[neil_w]

New version will be released when it's stable and ready, not before. It's getting there. Yes, it is bad that it's been 5+ years since the last release, but that is water under the bridge at this point, and no one can magically snap their fingers and fix everything all at once.

 

[Neutronium95]

I've been messing around with a three stage design this evening, and I've noticed a relatively large difference between the simulated apogee and the design panel apogee when I'm using a longer coast phase between the stages. I don't know if that's related to this issue, but it might be worth looking at.