Ka50 gearbox and airfoil

[AR_Reisen]

Hi

 

Im looking for information about Ka-50 gearbox and specially its reduction ratio (or main rotor rpm). I see that picture in an autorrotation thread, sameone related to ka50 will be so helpfully

 

Also I'm looking information about ka50 blade's airfoil, I know that it is a really hard information to found, probably clasified, but if someone knows anything about it...

 

Thanks

[tdar]

Are you interested in the airfoil section (like NACA0012 etc)? I would expect that to be classified but lets see if anybody at ED can answer your question.

[AR_Reisen]

Thanks for posting tdar.

 

I am interested in the airfoil characteristics (Cl,AoA slope) which i know that it is impossible to found

 

But I am much interested in gearbox reduction ratio, i dind't found any information in google or DCS manual, I am looking for ka50 main rotor angular speed (rpm)

 

Any ED guys could help me?

 

Thanks

[AlphaOneSix]

The schematic above is for the Ka-32, which is very similar but has a different gearbox than the Ka-50. It has been mentioned on this forum before, but I can't quite remember, but I think the nominal rotor RPM was 304 RPM.

[AR_Reisen]

Thanks alphaonesix

 

Im surprised that there isn't any information about engine or rotor rpm in DCS:BS manual (only percentage as cockpit tachometer)

 

Please, could you confirm that rpm o give me any link where could I found that information? I've been trying searchin in the forum but no results.

 

In any case thank you very much, I'll start working with those 304 rpm

[AlphaOneSix]

It's not 304 RPM, sorry...it's 313 RPM. My source is http://koavia.com/e_bp252.htm.

 

The Ka-50 uses the VR-80 main gearbox. The input RPM from the intermediate gearboxes is 6231 RPM, and the reduction is 0.05027, resulting in a nominal rotor RPM of 313. Note that "nominal" for the Ka-50 is (I believe) 89% on the rotor RPM gauge. That number (89%) should be in the flight manual, but I'm at work and can't check. I will double check it when I get home.

 

But anyway, for your calculations, you should uses 313 for the rotor RPM.

 

Also, in regard to the picture above of the Ka-32 gearbox, it should be noted that the engines on the Ka-32 input directly into the main gearbox, which is why you see an input of 15,000 RPM (nominal free turbine speed of the TV3-117VMA). On the Ka-50, the engines each go through an intermediate gearbox before getting to the main gearbox. The intermediate gearboxes take the 15,000 RPM input from the engines and reduce it to the 6,231 RPM that is input into the mian gearbox.

Edited March 3, 2009 by AlphaOneSix

[AR_Reisen]

thank you