Estimation of minimum power required

kolibri282

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Quote: I term as 'inflow' the air flow striking the (gyro) rotor from below. /Quote
That's correct, I think it is sometimes called total inflow. Induced inflow is the flow opposite to the aforementioned, which deflects the air that is entering the rotor from below downward. What leaves the rotor is the resultant inflow.
 

PW_Plack

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To be sure, you'd need a flowmeter. A pity that it costs 1400 dollars...
Actually, given the parameters Vance already knows about his engine, he could get very close using RPM and manifold pressure, which is fairly cheap to measure. For that matter, the prop will have a defined curve of RPM vs. percent power required.
 

Jean Fourcade

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a) Jean Fourcade:
https://www.rotaryforum.com/threads/gyrokit-library-and-gyrorotor-program.45141/
Jeans program written in JAVA, if you would like a version that runs in the eclipse IDE drop me a line with a private e-mail, I could send you a workspace for the Mars version of eclipse where I got the program up and running
Hi Jurgen,

Just a clarification, you don't need to install eclipse or any IDE to run the gyrorotor program. Just download the jar file and run it

Jean
 

kolibri282

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Hi Jean, great to hear from you, Bois de la Pierre was such a marvelous time....
When I started programming JAVA about twenty five years ago I used just the virtual machine and did all the configuration stuff on the command line, using batch files mostly, so, yes, I know that you don't need an IDE, but when I tried to fire up your program I had some trouble (as can be seen in the thread I started back then). Whether you run the program from the command line or from an IDE, you would in both cases have to configure the environment correctly. I seem to remember that a pivotal point is the CLASSPATH variable, which you set to locate all the components of your program. The advantage of using an eclipse workspace is, that the entire configuration is stored in the workspace as well, so using eclipse the program should run out of the box, once you switched to the workspace. I also remember that at one point I had to rename one of the class import statements and I actually don't understand why but again with the correct configuration that problem might be avoided. Is there perhaps a configuration file in your program I did not notice? In that case running the program would probably be straight forward.
Anyway, do you intend to resume working on your program? With mine I have added a fairly large module implementing the analytic formulae of naca 6763 and 7067 because I was time and again not able to see why the stability derivatives I had calculated numerically were far from the measured values. ( I can now even analyze tandem helicopters, but do not intend to build a tandem autogyro...;-) Currently I am implementing the control derivatives which will allow me to use a step function and compare the results to e.g. curves in old reports that were generated with analog computers. That brings me to a puzzle I have not been able to solve so far: the values for the Puma longitudinal control derivatives are given by Padfield as X_B1= -9.5 Z_B1=40.5 M_B1=6.52 while in other reports they are smaller by about two orders of magnitude. Is it possible, that in the reports with the smaller values these are given in percent, so that they would be smaller by 1/100th?

Well, I do hope you will find the time to resume working on your program since it was very helpful that I was able to compare my results with the ones you had obtained.

Happy Simming!


Juergen


PS: this year my wife and I spent a week cycling along the Loir during our holiday and visiting some châteaus. We passed by Chambord but did not enter, it is so huge that you might get lost but we did see Chenonceau and the Château d'Ussé, both very lovely indeed. After that we spent five days at Pornic, which is still a stronghold of the French, not many foreigners there.
 
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XXavier

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Hi Jurgen,

Just a clarification, you don't need to install eclipse or any IDE to run the gyrorotor program. Just download the jar file and run it

Jean

Thanks...!

I had to download something from Oracle, but it works quite well...
A bit too complex for me, but I find it very instructive...

BTW, Jean... I've been unable to to find, in the internet, your article 'Théorie du rotor en balancier' that you published in 'Vol Moteur' in 2001. It's not available, either, in the web page of the magazine...

Where could I find it...?
 

Jean Fourcade

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Hi Juergen,

If JAVA has been correctly installed, there is no need to initialize anything. A double click on the jar "et voila"

Yes, I will soon update a new version of Gyrokit Library

Nice Chambord isn't it ?

Jean
 

kolibri282

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Hi Jean and Xavier,
could you perhaps upload the file to some sharing site and post a link to the "Technical Papers, Books and Publications" section?

Thanks,

Juergen
 
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XXavier

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Hi Jean and Xavier,
could you perhaps upload the file to some sharing site and post a link to the "Technical Papers, Books and Publications" section?

Thanks,

Juergen
I received by e-mail this morning, from Jean Fourcade, two papers that he published in 'Vol Moteur' long ago. However, and in order to transfer them to the 'Technical Papers' section, I first need his authorization, as owner of the copyright...
 

kolibri282

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Thank you, Xavier, for taking the extra effort to clarify legal issues with posting Jean's publication to the rotary forum. I do hope that Jean is free to publish his text in the rotaryforum and not tied to any contracts with 'Vol Moteur'

Cheers,

Juergen
 
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