Interesting, what do you calculate? Weights first in and the output is the wing placement and/or static stability? Or do you input any geometry in it at all?
You don't have any Windows version of the program?
Which are the critical parameters? Stalling speed, take off distance? You maybe design to a category.
Pretty much the basic calculations which can be found from Raymer's Aircraft Design: Conceptual approach. It is going to also calculate the stability, but it is not implemented yet.
Currently it bases calculations on stall speed, wing loading and cruise speed criterias, uses altitude, Cd0 etc. parameters to accomplish that and finds maximum speed and cruise speed for a specified restricted power (engine of choice).
Todo list includes importing polars from airfoil program (Xfoil) and performing more accurate analysis based on that. I haven't started that yet, but it is a planned feature and necessary for realistic results.
There is no Windows-version of the program. You can get Ubuntu Linux for free or get a Mac :). I am not going to support Windows.
By the way, if someone else wants to create Windows binaries for the program, you can do it: it is free software, the source is available, and the UI is done with cross platform toolkit (Qt). It should work with just recompile in Windows. I am not planning to do that (I don't have Windows and I am not going to get one), but if somebody else wants to do that, feel free.
I also have a similar program. I input all the weights and basic moment arms into it so that I can use it to generate some advice to the planning. It outputs the static margin and the wing placement with cooper-harper-values. All components are listed and have weights, cg and distance x.
One could also fix everything as it is best and then play with the engine placement, since that is usually the most heavy item. Usually better to have the engine far from the firewall, so that it can be moved closer if required later.
I am also using the cooper-harper-flying qualities in the design process. But have some hard time to get those optimium. Maybe I have an error somewhere in my sources or similar.
BTW: There are several errors in the Raymer book, so be aware of that. :)
dodlithr: Is you program open source? Can I see/try it out? Can I see the source? The CG calculation page is on my program but the CG and static margin calculation is not yet implemented.
>I am also using the cooper-harper->flying qualities in the >design process. But have some hard >time to get those optimium. Maybe >I have an error somewhere in my >sources or similar.
Can you send me the sourcecode? We could join some efforts it seems. My sähköposti is karoliina dot t dot salminen at gmail dot com.
>BTW: There are several errors in >the Raymer book, so be aware of >that. :)
I have found at least one error. One equation gave funny results, but it was correct on another page (which was giving reasonable results). I have marked that in the book. I can post it in my blog once I find it. Can you please point me the errors you have found. Thanks in advance.
5 comments:
Interesting, what do you calculate? Weights first in and the output is the wing placement and/or static stability? Or do you input any geometry in it at all?
You don't have any Windows version of the program?
Which are the critical parameters? Stalling speed, take off distance? You maybe design to a category.
Janne.
Pretty much the basic calculations which can be found from Raymer's Aircraft Design: Conceptual approach. It is going to also calculate the stability, but it is not implemented yet.
Currently it bases calculations on stall speed, wing loading and cruise speed criterias, uses altitude, Cd0 etc. parameters to accomplish that and finds maximum speed and cruise speed for a specified restricted power (engine of choice).
Todo list includes importing polars from airfoil program (Xfoil) and performing more accurate analysis based on that. I haven't started that yet, but it is a planned feature and necessary for realistic results.
There is no Windows-version of the program. You can get Ubuntu Linux for free or get a Mac :). I am not going to support Windows.
By the way, if someone else wants to create Windows binaries for the program, you can do it: it is free software, the source is available, and the UI is done with cross platform toolkit (Qt). It should work with just recompile in Windows. I am not planning to do that (I don't have Windows and I am not going to get one), but if somebody else wants to do that, feel free.
ok.. sounds fair.
I also have a similar program. I input all the weights and basic moment arms into it so that I can use it to generate some advice to the planning. It outputs the static margin and the wing placement with cooper-harper-values. All components are listed and have weights, cg and distance x.
One could also fix everything as it is best and then play with the engine placement, since that is usually the most heavy item. Usually better to have the engine far from the firewall, so that it can be moved closer if required later.
I am also using the cooper-harper-flying qualities in the design process. But have some hard time to get those optimium. Maybe I have an error somewhere in my sources or similar.
BTW: There are several errors in the Raymer book, so be aware of that. :)
Regards: Janne.
dodlithr:
Is you program open source? Can I see/try it out? Can I see the source?
The CG calculation page is on my program but the CG and static margin calculation is not yet implemented.
>I am also using the cooper-harper->flying qualities in the >design process. But have some hard >time to get those optimium. Maybe >I have an error somewhere in my >sources or similar.
Can you send me the sourcecode? We could join some efforts it seems. My sähköposti is karoliina dot t dot salminen at gmail dot com.
>BTW: There are several errors in >the Raymer book, so be aware of >that. :)
I have found at least one error. One equation gave funny results, but it was correct on another page (which was giving reasonable results). I have marked that in the book. I can post it in my blog once I find it. Can you please point me the errors you have found. Thanks in advance.
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