Peter Cowan/Lexi Cameron wrote:
Are these narrow chord props significantly more efficient than the 6" blades
I see on a Hatzell sitting here or are there other reasons for going this
route?
Peter.
Perry Mick wrote:
And here is the blade chord, angle, and thickness
information for 6% at the tip and 12% at the root.
Somewhere between 4 and 6 inches it changes from
a 2.25 inch circle to a blade.
r, in. c, in. th, in. ba, deg 90-ba th / c %
4 4.00 0.52 71.47 18.53 13.07
5 4.00 0.51 67.27 22.73 12.68
6 4.09 0.50 63.31 26.69 12.30
7 4.26 0.51 59.61 30.39 11.93
8 4.38 0.51 56.17 33.83 11.57
9 4.50 0.50 52.98 37.02 11.22
10 4.62 0.50 50.05 39.95 10.88
11 4.67 0.49 47.34 42.66 10.55
12 4.73 0.48 44.85 45.15 10.23
13 4.78 0.47 42.56 47.44 9.93
14 4.81 0.46 40.45 49.55 9.63
15 4.81 0.45 38.51 51.49 9.35
16 4.81 0.44 36.72 53.28 9.08
17 4.81 0.42 35.07 54.93 8.81
18 4.77 0.41 33.55 56.45 8.56
19 4.72 0.39 32.14 57.86 8.32
20 4.68 0.38 30.83 59.17 8.09
21 4.59 0.36 29.61 60.39 7.87
22 4.49 0.34 28.48 61.52 7.66
23 4.38 0.33 27.43 62.57 7.46
24 4.26 0.31 26.44 63.56 7.28
25 4.09 0.29 25.52 64.48 7.10
26 3.92 0.27 24.66 65.34 6.93
27 3.76 0.25 23.85 66.15 6.78
28 3.54 0.24 23.09 66.91 6.64
29 3.32 0.22 22.37 67.63 6.50
30 3.10 0.20 21.70 68.30 6.38
31 2.87 0.18 21.06 68.94 6.27
32 2.63 0.16 20.46 69.54 6.17
33 2.38 0.14 19.89 70.11 6.08
34 2.14 0.13 17.90 72.10 6.00
--
Perry Mick
perrym@teleport.com
Duckt N7XR
http://www.mickaircraft.com/duckt.htm
Great work Perry. Can't wait to see those blades. Sooner or later we are
going to blow those silly piston guys into the weeds :-)
Paul Lamar
Peter Cowan/Lexi Cameron wrote:
Are these narrow chord props significantly more efficient than the 6" blades
I see on a Hatzell sitting here or are there other reasons for going this
route?
Peter.
I think Perry sized these for 150 HP. It is not the final design yet.
I am voting for 250 HP so the blades are likely to get wider as
the committee negotiates further :-)
Paul Lamar
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