The final factor that affects lift is the density of the fluid. The more dense it is, the more lift is provided by the fluid. If you imagine air molecules approaching and moving around the wing, and consider the fact that if you have no fluid, you have no lift, you can understand this. It is the molecules that make up the fluid that provide the lift. More molecules means more pressure which allows more lift (and also produces more drag).
To sum up, there are four things that affect lift:
- the shape and area of the wing
- the angle of attack
- the speed of the airplane
- the density of the air
The image at the left depicts the flowfield around the Space Shuttle Launch Vehicle traveling at Mach 2.46 and at an altitude of 66,000 feet. The surface of the vehicle is colored by the pressure coefficient (the red areas represent higher pressure). The gray contours represent the density of the surrounding air (the lighter gray shows higher air pressure).
Density
The more dense a fluid, the more _____ is provided.
lift
