3650 fluid dynamics

Question 1

gas

Answer 1

molecular proximity defined by container

Question 2

states of substances

Answer 2

gas liquids solids but all fluids and beyond solid are plasmas

Question 3

dynamic forces

Answer 3

lift and drag

Question 4

static forces and what they depend on

Answer 4

pressure and buoyancy - position, size, structure

Question 5

pressure

Answer 5

acting down on the substance

Question 6

weight

Answer 6

mg, pulling the substance down

Question 7

drag (2)

Answer 7

resistive force that results from DISORDERLY collisions with fluid molecules
opposing the action

Question 8

lift

Answer 8

pushing object up

Question 9

buoyancy (2)

Answer 9

supportive force produced by displacement of ORDERLY fluid molecules
- initially would not have if we dont have it in order until the fluids rearrange itself
pushing object up

Question 10

density and buoyancy

Answer 10

less dense -buoyant

Question 11

sum of Fy

Answer 11

-RU-w+RB

Question 12

RU and RB depends on

Answer 12

volume

Question 13

w depends on

Answer 13

mass

Question 14

density

Answer 14

mass/volume

Question 15

if the object has more volume

Answer 15

more buoyant

Question 16

object density =1

Answer 16

stay in the middle

Question 17

object density <1

Answer 17

float

Question 18

object density >1

Answer 18

sink

Question 19

drag increases with (4)

Answer 19

object cross section
fluid density
object velocity
fluid flow parameters

Question 20

laminar vs turbulent flow

Answer 20

straight undisturbed layers vs tiny disturbed whirpools

Question 21

with drag in the front

Answer 21

laminar flow tears up to create turbulent flows - disorganized

Question 22

laminar flow range (I)

Answer 22

smooth surface/low velocity - attract fluid molecules to it (surface layer) because of collisions of molecules equals high surface drag

Question 23

partially turbulent flow range (I)

Answer 23

pair of separation points with more velocity - some form drag
turbulent low pressure wake in the back
decreased surface drag
decreased support of fluid force from behind

Question 24

Partially turbulent flow range (II)

Answer 24

high velocity - more formed drag
little surface dry
decreased boundary
earilier separation point of boundry layer

Question 25

with rougher surface

Answer 25

more surface drag, full turbulent flow follows keeping the support behind

Question 26

if normal velocity puts it at the top end of 2, better to make surface

Answer 26

rougher - to make the fluid more viscous so the boundry layer becomes fuller

Question 27

magnus effect

Answer 27

on top you have lower velocity and high pressure
below you have high velocity and low pressure - pushing it down
boundary layer of air spinning with ball’s surface - surface drag
surface thrust - pulls molecucles higher

Question 28

gear effect

Answer 28

the ball keeps on bending - spin of the ball

Question 29

lift

Answer 29

supportive force produced by relative pressure on opposite sides of an object

Question 30

an object with a bump on its back

Answer 30

low pressure/high velocity on top and high pressure/low velocity on the bottom so it gets lifted - packet of air ends up at the same time