OpenRocket

[Lucifer]

OpenRocket is an awesome program. It stopped at 15.03 after numerous improvements.

I was really hoping on seeing pods and other stuff to simulate, like on the Big Ones (Delta IV, for example).

Any free programs out there that can deal with the aerodynamics of putting the engine rooms outboard, to drop off as they burn out?

 

[dhbarr]

OR is still under active development. Like many open source projects staffed entirely by part-time volunteers, the next version will be out when it's readyish. There's test versions floating around if that strikes your fancy.

 

[Cabernut]

Currently, debugging work is underway on ver. 17.11-rc2. In all likelihood the next release(with pods and many other goodies) will be an 18.0x

 

[rharshberger]

Any chance fins on transitions/boattails will be supported in the new version?

 

[K'Tesh]

Any chance fins on transitions/boattails will be supported in the new version?

Transitions and boattails have been supported for some time... Or at least, you could do them. The only thing that you can't do with them is add fins to them.

For fins attached to them, I use phantom body tubes to attach them, but I do have to put up with discontinuity in body tube diameter messages.

 

[K'Tesh]

@Cabernut

Any word about my mysterious shifting of decals in the debugging work? I sent the .ork, and haven't heard a thing since.

 

[rharshberger]

I am asking in reference too NOT having to use phantom tubes and tricks, actually being able to drop fins on transititions and boattails.

 

[neil_w]

I am asking in reference too NOT having to use phantom tubes and tricks, actually being able to drop fins on transititiobs and boattails.

In that case, nope.

 

[Leo]

Currently, debugging work is underway on ver. 17.11-rc2. In all likelihood the next release(with pods and many other goodies) will be an 18.0x

Do have a link to 17.11-rc2 ?

 

[Charles_McG]

In that case, nope.

Count(Pod) >= 2?

 

[neil_w]

Count(Pod) >= 2?

I believe it will support Count(pod) = 1.

However, I haven't touched one of the most recent builds; the broken 3D rendering sent me back to a February build for Alcubierre. That oldie doesn't let you save #pods = 1, so my temporary solution is to leave that design open in an OR window all the time.

 

[Cabernut]

I believe it will support Count(pod) = 1.
...

Pods <2 are "unofficially" supported. You have to manually change the number to 1 as it won't allow using the down arrow past 2. Simulation results, I believe, will be off with 1 as it won't account for the off-axis drag & CP. There wouldn't be any simulation warnings either.

I tested it a minute ago and a file will save with one pod(automatic positioning) and reopen correctly.

 

[neil_w]

I’ll take it.

 

[Andrew_ASC]

Nope. But I've seen university research level CFD Linux projects beat $54,000 Solidworks CFD. And the hypersonic professor with twenty years experience wants your fuel composition to run a simulation. Finds oblique shocks, gas particle interactions, exhaust plumes, and also computes drag coefficient so you can find the drag force at various angles of attack.

But Yeah... OR ain't bad for what it is. The other route took a complete 3D model and three weeks of real Sheldons not actors to get one number for one math equation so I could have a drag force accurate. Granted the other route works for real large spacecraft and tactical missiles as well as high power college design rockets... They basically re mesh your 3D model on a very fine level of detail. The sim itself took 15 minutes grinding through thousandths upon millions of math time varying functions of DE...

 

[Andrew_ASC]

The other Linux route is when you don't have a Mach 1.7 wind tunnel and you need engineering numbers for applications not in a artsy doofus way. You want to find the drag force on the fins to compute the joint failure and pin size for example. Needless to say as you exceed Open Rocket, the reality becomes complex to solve.

 

[Cabernut]

Nope. But I've seen university research level CFD Linux projects beat $54,000 Solidworks CFD. And the hypersonic professor with twenty years experience wants your fuel composition to run a simulation. Finds oblique shocks, gas particle interactions, exhaust plumes, and also computes drag coefficient so you can find the drag force at various angles of attack.

But Yeah... OR ain't bad for what it is. The other route took a complete 3D model and three weeks of real Sheldons not actors to get one number for one math equation so I could have a drag force accurate. Granted the other route works for real large spacecraft and tactical missiles as well as high power college design rockets... They basically re mesh your 3D model on a very fine level of detail. The sim itself took 15 minutes grinding through thousandths upon millions of math time varying functions of DE...

OK.

But I've seen better on faster machines, not telling you where.

How is this relevant to simming a model rocket? Ever hear of the K.I.S.S. principle?

 

[Andrew_ASC]

This was our senior design project sustainer stage for an overly expensive L-1 Multistage design at University Tennesee of Chattanooga. NASA won't even give you certain equations publicly and you start finding more technical data in .mil sources. You will find OR sucks at supersonic airfoils that taper from root to tip at higher mach applications. Thanks to Dr. Sreenivas and Dr. Newman. Those two were awesome researchers to help out the senior design project in support of SEDS competition. They told us OR was "off". :] We flew this bird in UTAH.

or incase it fails to display,

https://i.imgur.com/B3MZBqh.png

 

[rharshberger]

This was our senior design project sustainer stage for an overly expensive L-1 Multistage design at University Tennesee of Chattanooga. NASA won't even give you certain equations publicly and you start finding more technical data in .mil sources. You will find OR sucks at supersonic airfoils that taper from root to tip at higher mach applications. Thanks to Dr. Sreenivas and Dr. Newman. Those two were awesome researchers to help out the senior design project in support of SEDS competition. They told us OR was "off". :] We flew this bird in UTAH.

So you are doing what you do best, bashing hobbyist grade products for being inferior to university research accessible resources that most hobbyists will have no funds/desire/need. We here are hobbyists most of us enjoy flying rockets and designing unusual/non-performance designs.

So what!

Maybe I speak for myself only but your attitude is pissing me off, you dont have to hang out with us hobbyists since we obviuosly are not up to your caliber. I have family that works in the aerospace programs at AEDC, and you know most of the engineers I have met from there are not nearly as insufferable as you!

 

[Andrew_ASC]

We started with OR. It's way better than a rough idea. You can make it as complex as you want is all I'm saying. The 20 yr hypersonics dork pulls out a hand calculator, and he pissed me off saying OR was 0.4 Mach off. I still won't believe it. Lol.

 

[Andrew_ASC]

Plus if you read the thesis paper on OR the author admitted he didn't have the CFD knowledge, it's hard to pick a bone with a FREE program, but there are limits.

 

[Cabernut]

Plus if you read the thesis paper on OR the author admitted he didn't have the CFD knowledge, it's hard to pick a bone with a FREE program, but there are limits.

The point is, it doesn't matter. We don't care. Keep It Simple Stupid means that since, for example, there is a + or - 10% total impulse for our motors, anything beyond OR/Rocksim/etc. is unecessary.

You're clearly trying to impress us with all this overkill. It's not. I've seen this a time or two. Usually with young college students that think knowledge equals intelligence.

 

[markkoelsch]

The point is, it doesn't matter. We don't care. Keep It Simple Stupid means that since, for example, there is a + or - 10% total impulse for our motors, anything beyond OR/Rocksim/etc. is unecessary.

You're clearly trying to impress us with all this overkill. It's not. I've seen this a time or two. Usually with young college students that think knowledge equals intelligence.

I could not agree more. If folks realized how much of a deal it is just to get a good mesh for CFD- sure, it is a superior method. I would love to have the time, knowledge, and money to play with this, but alas I do not.


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