
Computed Performance Predictions of Wright 1900 Aircraft Replica

Glenn
Research
Center

Engineers make mathematical predictions of the performance of any
new aircraft
as part of the
design process.
These predictions use the best data and mathematical techniques
which are available to the engineer. As the Wright brothers were
designing their
first aircraft,
the basic principles of
aerodynamics
were being discovered. The brothers made mathematical predictions of the performance
of their aircraft. And when their actual performance did not agree
with their prediction on the
1901 aircraft,
they built their own
wind tunnel
to refine their predictions and to discover the solution to other
performance problems.
For our full scale
replica
of the Wright 1900 aircraft, we have also made mathematical predictions
of the aircraft performance. NASA engineers in the twenty first century
have many new tools available to make these predictions; tools which
were not available to the Wright brothers. The newest tool is the use of
computers to predict aircraft performance. Computers can solve
equations
which model the flow of air around an object. The models can be made very
simple by neglecting certain effects, or they can include all the complexity
of flowing gases. Simple models run fast on small computers and complex
models take a long time on a big computer. Simple models give first
approximations to the final answer and complex models can give very accurate
answers.
You can
interactively predict
the performance of our replica by using a specialized version of our simple
FoilSim
program. This program computes an ideal flow around a single airfoil.
A more
accurate prediction
of performance has been computed by
Eric McFarland of NASA Glenn Research Center. His program computes the
interaction of the top and bottom wings, the canard, and the ground. Here
is a sample of his computed results:
This computation was performed for a wind velocity of fifteen miles per hour, and the
aircraft flying five feet above the ground. The computed pressure is color coded and
you can determine the value of the pressure by comparing to the color bar.
With this computation, we see that most of the pressure changes take place
near the leading edge of the airfoil. The pressure on the upper surface of
each wing is lower than the pressure on the bottom surface. Notice that
the pressure on the top wing is slightly different than the pressure on
the bottom wing because the flow around each wing interacts with the other.
Navigation..
 ReLiving the Wright Way
 Beginner's Guide to Aeronautics
 NASA Home Page
 http://www.nasa.gov
