Fluid mechanics Flashcards
What is fluid mechanics concerned with?
The movement of liquids and gasses.
What does a drag force do?
Slows the object as it moves in the opposite direction to the object.
What is meant by surface drag?
The friction between the surface of an object and the fluid environment.
How can an athlete reduce surface drag?
Wear specialised smooth clothing or shave hair from their skin.
What is form drag?
The impact of the fluid environment on an object.
How can an athlete reduce form drag?
Streamlining and slipstreaming.
What is streamlining?
Shaping a body so it can move as effectively and quickly through a fluid as possible.
What is slipstreaming?
Moving behind another moving object to minimise turbulent air and form drag.
How does the velocity of the object affect the drag it receives.
The greater the velocity = greater drag because of greater air resistance.
How does the cross-sectional area of the object affect the drag it receives?
The larger the cross sectional area = the more drag (much like a sail on a pirate ship)
How does the shape and surface of an object affect the drag it will receive?
More aerodynamic shape and smoother surface = less drag.
What is a lift force?
A force that causes a body to move perpendicular to the directional of travel.
What is the Bernoulli principle?
Air molecules exert less pressure the faster they travel.
What is meant by the angle of attack?
The tilt of the projectile, relative to the direction of motion.
How is the Bernoulli principle used in discus?
Underneath the discus, air travel at lower speeds because of the angle of attack, causing a higher pressure below it and a lower pressure above it. This pushes the discus up
How is the Bernoulli principle used in F1 racing?
The angle of attack of the spoiler on the back of the cars causes downforce on the rear end of the car. This allows for the car to have more friction with the ground, making cornering more effective.
