Transcript Poster

Lift and Drag versus altitude for a passenger airplane wing
Abstract
This presentation is to explore the
relationship of lift and drag with respect
to the altitude of an airplane wing. In
order to conduct such experiment, we
used a CFD software called Caedium to
simulate.
Historical Data
This is the graph of pressure and temperature
with respect to the altitude. By plotting the Air
pressure versus the air density, we found that
they are almost linearly dependent.
Therefore, we can just simply change pressure
to cover for the change of density. Note that
the scaling of the right y-axis is Kpa but the
scaling of the left axis is K. Therefore, the
degree of change is hugely different for
temperature and pressure.
The general cross-section shape of an airplane wing.
higher velocity on top of the wing which results in a lower
pressure.
A lower velocity on the bottom of the wing which results in
a higher pressure.
This difference in pressure results in a net upward force
known as a lift.
Velocity
In the figure above we see the general cross-sections shape of an airplane wing. The
brighter color stands for the higher velocity. As air flows from left to right we see they
higher velocity on top of the wing and a lower velocity on the bottom of the wing.
Force
According to the
Bernoulli equations
Therefore, due to the
difference of velocity
on the top and bottom,
the pressure will be
produced so is the
force. In the vertical,
the net force is lift.
The figures show arrow map of the forces exerted on the surface of the wing. The
higher the cones are represent greater force acting on that section of the wing.
Conclusion
The Drag Force increases as the altitude gets lower and similarly, the Lift Force increases as the altitude
decreases.
For the altitudes between 6000 meters and 16000 meters we see a change in temperature of approximately 32.5 degrees Celsius while the change in pressure surmounts to be 37000 Pa.
Thus the lift force and the drag force are negligible when it comes to determining how high an airplane should fly.
Other factors such as turbulence, the viscosity of the air, frictional force and heat transfer that affect the flight
path.
It is common for flight experts to change the path of flight based of wind conditions and weather variations.