Hydrodynamic II

Question 1

what is the relationship between velocity and cross sectional area?

Answer 1

inversely proportional

Question 2

In a cylinder, where does liquid flow the fastest?

Answer 2

In the center (innere Zylinder) where r = 0

Question 3

Equation for driving force, FD in a cylinder

Answer 3

F = π r2 ΔP (P = pressure)

Question 4

Apart from the driving force FD, there is also a frictional force FF applied on the cylinder

Answer 4

Notes

Question 5

velocity for any position (r) in the tube : FORMEL

Answer 5

NOTES

Question 6

center of a large tube (larger R) the flow is faster than in the center of a small tube

Answer 6

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Question 7

Hagen-Poiseuille equation + UNITS

Answer 7

Notes

Question 8

decreased radius

Answer 8

for the same flow Jv, ∆P (blood pressure) must be increased

Question 9

higher Hematocrit (RBC levels)

Answer 9

Blood becomes more viscous

Question 10

Moens-Korteveg equation

Pluse speed Vp

Answer 10

NOtes

Question 11

The critical Re depends on the angle α of the branching (Re is higher for a high angle).

Answer 11

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Question 12

Some questions to test your understanding
: what is the meaning of the Hagen-Poiseuille equation ?
-at which power depends the flow on the radius of the tube ?
-on which other parameters depends the flow J ?
-untypical properties of blood flow?
(viscosity and Hämatokrit, Moens-Korteveg, Farhaeus-Lindquist-effect)

Answer 12

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Question 13

Flagellar propulsion onwards not done

Answer 13

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