Bruce's Fluid Dynamics Final Prep Flashcards Preview

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Flashcards in Bruce's Fluid Dynamics Final Prep Deck (52)
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1

Pressure definition ?

the force per unit area applied in a direction perpendicular to the surface of an object

2

Hydrostatic pressure

(AKA: Stagnation Pressure) The pressure at any given point of a non-moving fluid

3

what do we measure with our manometers ?

Static Pressure

4

Hydrostatic Pressure - Static Pressure =

Dynamic Pressure

5

‘Where the velocity of the fluid is high

the (static) pressure is low’

6

Static Pressure + dynamic pressure =

Total Pressure

7

Bernoulli's Priciple =

P+1/2pv^2 = Po
P=static pressure
p=density of the fluid
v=flow velocity
Po=total pressure

8

Velocity is directly related to ?

=Flow
and inversely related to cross sectional area.

9

Boundary layers are slower in ?

the edge

10

Boundary layers are faster in ?

the middle

11

3 types of fluid flow in pipes ?

• laminar
• turbulent
• transient

12

Laminar Flow =

happens when dealing with small pipes and low flow velocities

13

Turbulent Flow =

- vortices, eddies and wakes make the flow unpredictable
- happens in general at high flow rates and with larger pipes

14

Transitional Flow =

mixture of laminar and turbulent flow, with turbulence in the center of the pipe, and laminar flow near the edges

15

Transient flow range =

2300 < 4000

16

Laminar Flow range =

RE < 2300

17

Turbulent flow range =

RE > 4000

18

Reynolds number (Formula) =

Re =
(velocity)(radius)(density)
_____________________
Viscocity

19

Poiseuille's law on blood circulation in the body is dependent on what?

Laminar flow

20

In turbulent flow the flow rate is proportional to the

square root of the pressure gradient

21

atheroma = turbulent flow

is an accumulation of degenerative material in the tunica intima (inner layer) of artery walls.

22

Rapid changes in vessel diameter may lead to what?

Turbulent flow

23

As the blood leaves the arterial cannula, it is ____ flow?

Turbulent

24

Poiseuille’s Law:

Delta P =8u L Q / pi r^4

Delta P = pressure loss
L = length of pipe
u = dynamic viscosity
Q = volumetric flow rate
r = radius
d = diameter
pi = mathematical constant Pi

25

As length increases. .

-Resistance Increases
-Flow decreases
for a given pressure

26

As radius increases. .

-Resistance decreases
-Flow increases
for a given pressure

27

which oxygenator circuit has a lower resistance ?
series or parallel?

parallel

28

Two variable that we manipulate that alter blood viscosity:

1-Temperature
2-Hematocrit

29

Viscosity definition ?

a measure of the resistance of a fluid which is being deformed by either shear or tensile stress

30

water is "thin", having a ?

lower viscosity