Propeller thing !

[First time Juke]

I did that TS II design years ago and now when I downloaded the thrust HP I finally got some proof to the basic idea that I had on mind when doing the 3-views.

First I tried to solve why Tsunami was not an outright winner despite small size it possessed. One detail started to bug me...why did they change the prop so often ? I tried to guess..they had too short landing gear oleolegs to be able to install a bigger prop.

Okay a small plane does not need a big prop...but...if a plane could swing a bigger but 2 blader prop it might have the edge.

Eventhough the thrusthp does not give accurate figures ( it gave 27 440 hp need for Mustang prop at 511 mph ).

I placed first 2,8 metre 2 blade prop ( 110 inch ) and the 110 inch 4 blader....and finally 126 inch 2 blader ( 3,2 meters )..and guess what...the 126 inch had same thrust ( 10 600 lbs ) and speed at same rpm as the 110 in 4 blader ( 11 200 lbs ), but needed less hp:s to do it.

I hope I am right..all in all my racer seemed to need half the hp:s as Mustang..but not sure if that is enuf. I can increase the prop into 3,7 metre dia..but it looks too big for the plane ( in sideview a 2,8 metre is shown.

Never mind the small racer....it is my toy...and 425 mph at 2 x 70 hp engines..hopefully !




best regards,

Juke

[First time Juke]

Re: Propeller thing !

Here with the thrust data visible and same type prop....a bigger dia 2 blade uses less hps and has more thrust in fact than a 4 blader.

[Skyracer]

Re: Propeller thing !

Here with the thrust data visible and same type prop....a bigger dia 2 blade uses less hps and has more thrust in fact than a 4 blader.

Provided you can find a prop that will work with a tip speed around mach 2.2.

[mustang5151]

Re: Propeller thing !

Provided you can find a prop that will work with a tip speed around mach 2.2.

OR...one helluva reduction gear. Cool pics though.

[David E. Wells]

Re: Propeller thing !

Cool .

Must be KOLD in Karelia...but I Love your Enthusiasm...D.

[First time Juke]

Re: Propeller thing !

Provided you can find a prop that will work with a tip speed around mach 2.2.

You got me there SKYRACER !

Now this program is starting to make sense....finally thanks.
I bet I can give you better figures for P 51D prop..who has the prop arch diameter for a racing Mustang ? If you know it..add it here too; http://en.wikipedia.org/wiki/P-51_Mustang

There is also a chart to show how 560 mph would affect ( prop size increased a bit ). 4th to show a bigger prop at low rpm ( most thrust ). 5th a p51D ( if 12 foot prop ? ) vs. TS II situation.

Here are more moderate rpm:s;

[First time Juke]

Re: Propeller thing !

Dudes,

You made me real humble now...here is what I found out;

http://www.unlimitedexcitement.com/Pride%20of%20Pay%20n%20Pak/Rolls-Royce%20Merlin%20V-1650%20Engine.htm

0.491:1 reduction means that at 2900 rpm the prop revols 1430 rounds per minute...am I correct ?

rgds,

Juke

I bet there is something that the ThrustHP cannot do...actually calculate the speed for the racer. Lift of the prop is in a big role here..the 4-blader prop has enermous liftforce ( thrust ? ).

One thing remains a fact despite all this...the more weight and drag the plane has the bigger the prop has to be to be able to go really fast.

[First time Juke]

Re: Propeller thing !

Someone here claims Me 109 prop never turned faster than 1662 rpm.

http://forums.x-plane.org/lofiversion/index.php?t3184.html

Skyraider and F8F prop size can be found here;

http://www.aviation-history.com/garber/vg-bldg/grumman_F8F-1_f.html

[Skyracer]

Re: Propeller thing !

What unit of measure is used for pitch entry in your ThrustHP Calculator (feet, inches, cm)? Something seems weird with that number.

[First time Juke]

Re: Propeller thing !

That is a model aviation program uses inches...and possibly does not understand Reynolds numbers causing a real size Mustang prop induced change of drag..or something is this direction. Since the horsepower demand increases when the real size P 51D prop is at APC ( or any other given prop ) form.

And if someone informed about the racer prop sizes I'd be very grateful..and able to design it ( TS II ) little better.