
Velocity Effects
Answers


 Go to the Foilsim
Software Program and set initial conditions as follows: Airspeed(velocity)
= 50 km/h, Altitude = 5000 m, Angle = 1 deg , Thickness = 12.5, Camber
= 12.5, Area = 5 sq. m.
What is the Lift?
595 Newtons
 Change the velocity(airspeed)
as shown in the following table and record the associated lift for each
velocity to complete the table.
Velocity(km/h)
 Airspeed

Lift(Newtons)

50

595

100

2,378

150

5,351

200

9,513

250

14,860

300

21,400

400

38,050

TABLE 1
 Construct a graph
of Velocity's effect on Lift with an Independent Variable(X) of Velocity
and a Dependent Variable(Y) of Lift. Label each axis correctly to include
units. Print out graph from Foilsim Program...
 What is the shape
of the curve formed by this relationship? Parabolic
Shape
 Write the equation
for this relationship! y = cx^{2}__Where
y = lift, and x = airspeed_and c = a constant
 What is the value
of the constant in this equation for this set of conditions?
C = .23784
Newtons/kph^{2}
 Interpolate the
lift for a velocity of 350 kph. What is the lift? 29,130
Newtons
 Extrapolate the
lift for a velocity of 500 kph. What is the lift?
59,460 Newtons
 Based on the relationship
between lift and velocity, how would you increase the lift on a wing?
Increase the Velocity
 Set the initial
conditions provided in Problem 1 above and assume: g = 9.8 m./sec.^{2
}at this elevation; total weight of airplane, cargo, and fuel =
5000 kg.; weight of airplane = 3000 kg. ; weight of cargo and fuel =
2000 kg. Use the equation for lift that you generated in Problem 5 to
answer these questions:
 What
is the lift in Newtons required to maintain altitude in these
conditions?
49,000
Newtons
 What is the
velocity that is required to maintain this lift?
454
kph
 One hour later
all cargo is parachuted off the airplane and 200 kg. of fuel remains.
 What
is the lift in Newtons now required to maintain altitude?
31,360
Newtons
 What is the
velocity that is now required to generate the lift?
363
kph
