New Version of the Free RASAero II Software Released

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Chuck Rogers

Well-Known Member
TRF Supporter
Joined
Jun 7, 2011
Messages
260
Reaction score
263
To All:

A new version of the free RASAero II software (Version 1.0.1.0) has been released, and is available for download from the RASAero web site at www.rasaero.com . A link to the new version of the RASAero II software is on the home page, or click on the RASAero II Software and RASAero II Users Manual buttons to access the web pages to download the new version of the software and the updated users manual.

The updates to RASAero II in the Version 1.0.1.0 of the software are listed below.



RASAero II Version 1.0.1.0 – Release Date August 5, 2016

Changed the recommended stability margin for subsonic Mach numbers to a stability margin of 1.0 calibers, kept the recommended stability margin for transonic and supersonic Mach numbers at 2.0 calibers, for the marginal stability warning message.

Added extension to power-on base drag model for very large nozzle exit diameters at supersonic and hypersonic Mach numbers, with the nozzle exit area filling a large portion of the rocket base area, for more accurate power-on drag coefficient (CD) predictions for first and second stages of satellite launch vehicles.

Added stability margin (calibers) to the Flight Simulation plots.

Added additional outputs to the Flight Simulation Excel (.CSV) output file.



The extension to the power-on base drag model for very large nozzle exit diameters at supersonic and hypersonic Mach numbers came about from RASAero II being used to generate aero data for flight simulations for orbital launch vehicles for undergraduate/graduate student studies and for proposed small space launch vehicles. Launch vehicles, in particular the second stages of launch vehicles, can have very large nozzle exit areas that fill most of the base area of the first or second stage. For a launch vehicle on an ascent trajectory to orbit almost all of the flight within the atmosphere is “power-on” relative to the drag coefficients (CD’s) used for the launch vehicle.


The RASAero II authors, Chuck Rogers and David "Coop" Cooper, are always looking for high power rocket and Tripoli Research/amateur rocket flight data to compare the RASAero II altitude predictions against to further develop and improve the RASAero II aerodynamic prediction and altitude prediction models. The flight data and rocket information can be sent to the e-mail address below.


Additional information on the RASAero II software can be found on the RASAero web site at www.rasaero.com . The RASAero II authors, Charles E. (Chuck) Rogers and David (Coop) Cooper can be contacted at [email protected] .



Chuck Rogers
Rogers Aeroscience
 
Dear Sir,

I have used the software RS Aero II and found it very promising. I am using it to teach students the basics of aerodynamics. I wanted to ask a simple question regarding the software. The software gives only a single value of drag coefficient; which component is it, I mean pressure or viscous? I hope you will have a satisfactory answer.
 
Dear Sir,

I have used the software RS Aero II and found it very promising. I am using it to teach students the basics of aerodynamics. I wanted to ask a simple question regarding the software. The software gives only a single value of drag coefficient; which component is it, I mean pressure or viscous? I hope you will have a satisfactory answer.

Dr. Jamshed:

The components of drag and lift are printed out in the output file generated by the Run Test feature in RASAero II. The Run Test feature is detailed on Pages 86-92 in the RASAero II Users Manual, which can be downloaded from the RASAero web site. The drag components and lift components which are printed out are detailed on Pages 90-92 in the Users Manual. Friction drag, pressure drag, wave drag, base drag, protuberance drag (rail guide/launch shoe/launch lug drag), potential and viscous normal force coefficients; all are detailed in the Run Test output.


Charles E. (Chuck) Rogers
Rogers Aeroscience
 
I am not running a Run Test , (cos I do not have enough data to input), I simply design a rocket body and just see Aero plots, in that data it only shows Drag power on, Drag power off and CN (with potential and viscous). Can I get the components of drag there?
 
I am not running a Run Test , (cos I do not have enough data to input), I simply design a rocket body and just see Aero plots, in that data it only shows Drag power on, Drag power off and CN (with potential and viscous). Can I get the components of drag there?

Only the summary aero output data is included on the Aero Plots plots, and the table under the plots. To get all of the drag and lift components, you have to run Run Test.

If you've entered a rocket body, you can go to Run Test (under Tools, next to Files on the top bar), and run Run Test for the rocket body. Be sure to also include the nozzle exit diameter for the motor being used on the body/rocket, if there is one. Click on the Run Test button, and you'll get the output file.


Charles E. (Chuck) Rogers
 
Dear Sir,

Thank you very much for your kind reply. I am very happy now to run Run Test. Except that software gets closed when I want to see the output file or want to save the software file after clicking the Run Test. I think its Windows 10 problem. Any suggestions on that would be helpful.
One more question is, can we see the roll reversal phenomenon in this version? Is there any way we can add canting to the fins?
 
I have successfully run RASAero II on my Linux Mint machine using WINE. Just ran the install program and it installed fine.

Only wish is that it would accept .ork and .rkt files!
 
It does import .rkt files.
Well, it imports some .rkt files. I don't think it works with free-form fins, for example (which is fine, I'm not complaining.)

I think it's fair to say that RASAero is only needed for fairly extreme flights; I've used it for my BALLS MD and two-stage projects, and the Class 3 committee likes to see RASAero results. But there's a learning curve and probably it's overkill for most sport flying.
 
Well, it imports some .rkt files. I don't think it works with free-form fins, for example (which is fine, I'm not complaining.)

I think it's fair to say that RASAero is only needed for fairly extreme flights; I've used it for my BALLS MD and two-stage projects, and the Class 3 committee likes to see RASAero results. But there's a learning curve and probably it's overkill for most sport flying.
Just saved a .ork file to a .rkt using OpenRocket. Then imported the .rkt file into RASAero II. It was a tube fin design. Lost the fin-tubes, motor mount, everything but the nosecone and airframe. Tried it with a regular design. Same losses. I don't know if it's OR's error in the conversion to .rkt, or if it's RASAero's error in the import, or a combination.

I'm attaching the originals and the .rkt versions. I'd appreciate if anyone can check out the .rkt files with RockSim and tell me if OpenRocket did a proper conversion/save or not. When I reopen both in OR, I lose the fin-tubes but nothing else on DeepGroove and everything seems to make the transition to .rkt for the fiberglass DRM.
 

Attachments

  • 4in-derbigfiberglassredmax.ork
    525.2 KB · Views: 16
  • 4in-derbigfiberglassredmax.rkt
    17.7 KB · Views: 15
  • DeepGrooveTube.ork
    34.7 KB · Views: 14
  • DeepGrooveTube.rkt
    15.6 KB · Views: 16
Just saved a .ork file to a .rkt using OpenRocket. Then imported the .rkt file into RASAero II. It was a tube fin design. Lost the fin-tubes, motor mount, everything but the nosecone and airframe. Tried it with a regular design. Same losses. I don't know if it's OR's error in the conversion to .rkt, or if it's RASAero's error in the import, or a combination.

I'm attaching the originals and the .rkt versions. I'd appreciate if anyone can check out the .rkt files with RockSim and tell me if OpenRocket did a proper conversion/save or not. When I reopen both in OR, I lose the fin-tubes but nothing else on DeepGroove and everything seems to make the transition to .rkt for the fiberglass DRM.
All you are going to get is the overall shape. You will need to add the weight and cg manually. And as Mikec said, you can only import trapazoidal fins.
 
All you are going to get is the overall shape. You will need to add the weight and cg manually. And as Mikec said, you can only import trapazoidal fins.
Hmmm...so no parallelogram fins, much less tube fins. Doesn't look like it's going to help me for most of my projects unless I want to create them in RAS from scratch.
 
Hmmm...so no parallelogram fins, much less tube fins. Doesn't look like it's going to help me for most of my projects...
As I said, IMHO there is not much point in using RASAero unless you are going significantly supersonic.
 
As I said, IMHO there is not much point in using RASAero unless you are going significantly supersonic.

There are more reasons when deciding which software to use. I work with all members of the Big 3: RAII, RS, OR, and found these pros/cons.

-RockSim is very poor starting at M=0.8, not just significantly supersonic. OR and RAII are preferred.

-OR is way overly-pessimistic on stability. RS and RAII, with their modified Barrowmans, are more reasonable.

-OR's launch site elevation/atmosphere model is screwed up. If you fly in Denver, beware. RS and RAII look to have better implementation of the Standard Atmosphere offsets.

So, RAII has the technical stuff correct, IMO. My main beef with RAII is the ease of use. It doesn't add in the mass and CG of the motor. You have to do that manually, which makes it a royal PITA to compare different motors before you fly. Also, I am not a fan of English units.

Don't expect seamless I/O of the rkt file format in each software. Be happy if you get the basic outline of the rocket as a starting point.
 
Chris, I am afraid I did not find my answer. Let me repeat my question that software gets closed when I want to see the output file or want to save the software file (the .CDX1 file)_ after clicking the Run Test. I think its Windows 10 problem. Any suggestions on that would be helpful.
One more question is, can we see the roll reversal phenomenon in this version? Is there any way we can add canting to the fins?
 
Chris, I am afraid I did not find my answer. Let me repeat my question that software gets closed when I want to see the output file or want to save the software file (the .CDX1 file)_ after clicking the Run Test. I think its Windows 10 problem. Any suggestions on that would be helpful.

Can't really help on this. Works on other Windows 10 computers I use. One option is to edit the CDX1 file, then save the file. Then open the file, go straight to Run Test, then right after Run Test is pressed and the output file is generated, then press Cancel, and then exit the software. In any case, check and see if the Run Test output file was generated.

One more question is, can we see the roll reversal phenomenon in this version? Is there any way we can add canting to the fins.

The RASAero II software currently does not allow canted fins. There is no input for fin cant.


Charles E. (Chuck) Rogers
 
Hi, just starting with RASAero, but I can't seem to install the software - its asking me for the .NET framework but I already have .NET installed correctly.. Any ideas?
 
I don't think Chuck hangs out here very much. You might be better off e-mailing him directly.

Hey, I hang out here! :)

I also can be e-mailed directly at the e-mail address under User Support on the RASAero web site ( www.rasaero.com ).

This problem was addressed in the "RASAero II Question" thread.

Repeating from the thread:

I relayed your question to the other co-author of the software, David "Coop" Cooper. He says this problem has come up in the past for a few users.

Coop says to Google "Enable .net 3.5" and you will find the fix.


Charles E. (Chuck) Rogers
Rogers Aeroscience
 
Hey, I hang out here! :)

I also can be e-mailed directly at the e-mail address under User Support on the RASAero web site ( www.rasaero.com ).

This problem was addressed in the "RASAero II Question" thread.

Repeating from the thread:

I relayed your question to the other co-author of the software, David "Coop" Cooper. He says this problem has come up in the past for a few users.

Coop says to Google "Enable .net 3.5" and you will find the fix.


Charles E. (Chuck) Rogers
Rogers Aeroscience

It worked! Thanks Chuck!
 
Back
Top