In Depth: The Propeller
overview research materials and methods performance use
The Challenge:

Test the propellers' performance in a full scale wind tunnel. Compare the results to those of the Wrights.

The Wrights recorded two static thrust measurements for the 1903 propellers, one for the 1904 propellers, and one for the 1911 propeller. These data points were the targets for the tests. When the data was plotted out against the Wrights', the team would easily see the result of their efforts.

The Wright Story: Background
Education Feature: Designing a test in the sand...
resources
Download the Evolution of Wright Flyer Propellers between 1903 and 1912 paper (.pdf file-350K).
The Wright Experience at Work: Performance

The tests were run in collaboration with Old Dominion University who own and operate the NASA-Langley Full Scale Wind tunnel in Hampton, Virginia. Two sets of tests were run: one for the 1911 bent-end propeller, and one for both the 1903 and 1904 propellers.

test club mounted on the pylon

Video - 500K
THE SETUP: The propellers were tested using an electric motor mounted atop a pylon in the tunnel. The motor's performance was measured (using a flat bladed "club"—an object of known resistance, and the motor's rpm) as a basis for the measurements of the propellers.
prop test

Video - 500K
THE TEST: With atmospheric conditions recorded, the propellers were turned at increasing speeds, both with and without the air moving through the tunnel. Measurements were taken for speed, torque, thrust, and efficiency.
ODU team
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THE RESULTS: The data from the tests were analyzed by the team's collaborators at Old Dominion University, led by Dr. Robert Ash. The team could not have been more pleased with the outcomes:
  STATIC THRUST COMPARISONS
Wright Brothers Wright Experience
1903 67 lbs thrust at 350 rpm 64 lbs thrust at 350 rpm
1904 160 lbs thrust at 377 rpm
(pair of propellers)
82.66 lbs thrust at 377.8 rpm (single propeller)
The 1903 and 1904 propellers static thrust performances showed "very good to excellent agreement" with the Wright's own tests. The 1911 propellers efficiency was measured at 81.5%-an amazing result, as the best wooden propellers of today are capable of 84-85%. The complete results of the tests were published in papers by Old Dominion University and the Wright Experience. You are welcome to download the summary paper Evolution of Wright Flyer Propellers between 1903 and 1912(.pdf file-350K).

©2001, The Wright Experience™

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