drag Flashcards
drag
force created by the dynamic action of a fluid that acts in the direction of the force stream fluid flow
-resistance force as an object passes through it
total drag
=skin drag + form dragm+ wave drag
skin drag aka surface drag
1) velocity of fluid passing over object
2) velocity of object moving through fluid
3) smoothness of object
skin drag
influences:
-smoothness/roughness (hair)
-velocity of object
-velocity of fluid
form drag
influenced by:
-relative velocity
-size of surface area perpendicular of there fluid flow
stream lining
-seen in cars
-taper front and back- improves pressure difference
wave drag
-front edge meets water
influenced by:
-up and down motion
-relative velocity of fluid
-relative velocity of object
-surface area coming in contact
lift force
Bernoulli’s principle
-downward and upward force
-perpendicular to fluid flow
influences:
-angle of attack (airplane speeds up, tilt)
-coefficient of lift
-velocity
-area
-fluid density
-lift/drag ratio
Magnus effect
-spin
-top and back spin
-side spin
*backspin lift force due to spin