Introduction to Biomedical Engineering I · The fluid is nonviscous In a nonviscous fluid, internal friction is neglected. An object moving through the fluid experiences no viscous

Lecture 3

ETY494 – Introduction to Biomedical Engineering (2019 Spring Semester)

MATERIALS SCIENCE AND TECHNOLOGY DEPARTMENTUNIVERSITY OF CRETE

BME

Examples of BME

Evolution of the modern health care system

Notable figures in BME

Ethics and Morality

Career as BME

2https://www.imoney.sg/articles/career-tips/

3https://newvitruvian.com/explore/questions-vector-silhouette/

4

5https://blog.docsapp.in/the-right-amount-water-intake-and-urine-output/

6https://www.amazon.com/Mad-Science-Party-Balloons-Periodic/dp/B06XPTVTG7

7https://www.landolakes.com/recipe/16800/blue-ribbon-apple-pie/

21%

1%

78%

What does the pie represent?

N2

O2

Ar, CO2, etc

8https://www.newsbeast.gr/geuseis/arthro/2370017/panakota-me-siropi-vissino

9

10http://citadel.sjfc.edu/students/kes00898/e-port/phases%20of%20water%20page%20for%20unit.html

H2O

A fluid is a collection of molecules that are randomly arranged and held together by weak cohesive forces and by forces exerted by the walls of a container

Will deform under applied pressure A fluid can flow and take the shape of its

container Both liquids and gases are fluids. Mechanics of a fluid

Fluid Statics – fluids at rest Fluid Dynamics – fluids in motion

11

AIRPLANE FORMULA 1

12

http://scholarspoon.com/brain-drain-a-global-phenomenon/https://www.express.co.uk/news/world/613444/Michael-Schumacher-latest-F1-health-coma-Ferrari-Mercedes

https://www.youtube.com/watch?v=HsgZM2TXXy4

http://www.f1insight.co.uk/2013/04/how-diffuser-exhaust-rear-wing-create-downforce-grip-f1.html

13http://juniorcertscience.weebly.com/3a4-pressure.html

UNIT OF PRESSURE1 Pascal =1 N/m2

Suppose you are standing directly behind someone who steps back and accidentally stomps on your foot with the heel of one shoe. Would you be better off if that person were:

14

(A)1.90m85kg

Casual shoes

(B)1.65m50 kg

High heels shoes

https://www.abc.net.au/news/2017-11-13/why-do-we-wear-high-heeled-shoes/9135936

DIVING CLIMBING MOUNTAIN

15

http://www.hispotion.com/3-tips-start-climb-mountains-46841/mountain-climbing-wallpaper-2https://www.padi.com/courses/advanced-open-water

16https://courses.lumenlearning.com/physics/chapter/11-4-variation-of-pressure-with-depth-in-a-fluid/

17

If the liquid is open to the atmosphere and P0 is the pressure at the surface of the liquid, then P0 is atmospheric pressure.

P0 =1.00 atm = 1.013 x 105 Pa

Mass=density x Volume =ρV=ρAh

Raymond A. Serway, John W. Jewett - Physics for Scientists and Engineers, Volume 1, Technology Update-Brooks Cole (2015)

Implies that the pressure is the same at all points having the same depth, independent of the shape of the container.

A change in the pressure applied to a fluid istransmitted undiminished to every point ofthe fluid and to the walls of the container.

18https://www.christianitytoday.com/history/people/evangelistsandapologists/blaise-pascal.html

19

Hydraulic press

20

http://insightreplay.com/tech-sports-computational-fluid-dynamics/ https://www.carthrottle.com/post/nrgg7j6/

https://www.livescience.com/47446-fluid-dynamics.html https://giphy.com/gifs/paint-mixing-4POEoOBubrNIY

https://media.giphy.com/media/13L8EZXqkZM6xq/giphy.gif

STEADY OR LAMINAR

Each particle of the fluid follows a smooth path such that the paths of different particles never cross each other

In steady flow, every fluid particle

Arriving at a given point in space has the same velocity

21

https://www.wardsauto.com/technology/slippery-slope-production-cars-making-jaw-dropping-aerodynamic-gains

Raymond A. Serway, John W. Jewett - Physics for Scientists and Engineers, Volume 1, Technology Update-Brooks Cole (2015)

TURBULENT

Above a certain critical speed, fluid flow becomes turbulent

Turbulent flow is irregular flow characterized by small whirlpool-like regions

22Raymond A. Serway, John W. Jewett - Physics for Scientists and Engineers, Volume 1, Technology Update-Brooks Cole (2015)

23https://www.reddit.com/r/BeAmazed/comments/99csze/laminar_flow/

24www.imdb.com

Determines whether the fluid flow is laminar or turbulent

Non-dimensional velocity

laminar - when Re < 2300

transient - when 2300 < Re < 4000

turbulent - when Re > 4000

25https://study.com/academy/lesson/reynolds-number-definition-equation.html

26

https://www.mecaflux.com/en/regime_ecoulement.htm

https://slideplayer.com/slide/11622534/

YELLOW COLOR BLUE COLOR

27

https://graf1x.com/shades-of-yellow-color-palette-chart/ https://graf1x.com/shades-of-blue-color-palette/

28https://www.youtube.com/watch?v=05ECRklOak4

29https://www.saddlespace.org/whittakerm/science/cms_page/view/7795121

The resistance of a fluid to flow The measure of the internal friction of a fluid This internal friction, or viscous force, is

associated with the resistance that two adjacent layers of fluid have to moving relative to each other

Viscosity causes part of the fluid’s kinetic energy to be transformed to internal energy

Applies only in fluids The higher a fluid’s viscosity, the slower it flows

30

32

https://wiki.anton-paar.com/en/basic-of-viscometry/

NEWTONIAN FLUID

A Newtonian fluid's viscosityremains constant, no matter theamount of shear applied for aconstant temperature. Thesefluids have a linear relationshipbetween viscosity and shearstress (Fluids for which theviscosity is independent ofpressure)

Example Water Mineral oil Gasoline Alcohol

NON-NEWTONIAN FLUID

Opposite Example

Ketchup

Paints

Blood

Toothpaste

Shampoo

33

34https://www.youtube.com/watch?v=IyvFpuFeDYc

The fluid is nonviscous In a nonviscous fluid, internal friction is neglected. An

object moving through the fluid experiences no viscous force

The flow is steady In steady (laminar) flow, all particles passing through a

point have the same velocity The fluid is incompressible

The density of an incompressible fluid is constant The flow is irrotational

In irrotational flow, the fluid has no angular momentum about any point. If a small paddle wheel placed anywhere in the fluid does not rotate about the wheel’s center of mass, the flow is irrotational

35Raymond A. Serway, John W. Jewett - Physics for Scientists and Engineers, Volume 1, Technology Update-Brooks Cole (2015)

36

ρ1A1v1 = ρ2A2v2

A1v1 = A2v2 =constant

ρ is the (unchanging) density of the ideal fluid

https://www.pinterest.com.au/pin/820147782114362163/

velocity

37https://lawnlove.com/blog/lawn-watering-economics/

38http://hyperphysics.phy-astr.gsu.edu/hbase/pber.html

States that the sum of all forms of energy influid flowing along an enclosed path is thesame at any two points in that path

Assumptions

Flow is steady

Density is constant (incompressible)

Friction losses are negligible

39

𝑃 +1

2∙ ρ ∙ 𝑣2 + 𝜌 ∙ 𝑔 ∙ ℎ = 𝑐𝑜𝑛𝑠𝑡𝑎𝑛𝑡

40https://www.youtube.com/watch?v=UJ3-Zm1wbIQ

When fluid is at rest, v1=v2=0

41

42https://www.youtube.com/watch?v=046-DygKrhc

43https://en.wikipedia.org/wiki/Torricelli%27s_law

A venturi creates a constriction within a pipe (classically an hourglass shape) that varies the flow characteristics of a fluid (either liquid or gas) travelling through the tube. As the fluid velocity in the throat is increased there is a consequential drop in pressure

44https://steemit.com/steemstem/@theborges/flow-measurement-venturi-tube

45https://www.youtube.com/watch?v=WvFNqEPNPOc

By attaching manometers to three sections of the tube, the pressure drop can be measured and the flow rate through the throat calculated. This is termed a VenturiMeter

46

http://instrumentationbasicss.blogspot.com/2017/10/basics-of-venturi-tube.html

From Ancient Greek athḗra (ἀθήρα), meaning 'gruel‘ sklerosis (σκλήρωσις), meaning 'hardening‘

Atherosclerosis is a type of arteriosclerosis. Plaque (fatty deposits) clogs your arteries Made up of cholesterol, fatty substances, cellular

waste products, calcium and fibrin (a clotting material in the blood)

Causes arteries to narrow Less flexible Reduces blood flow Lessens the amount of oxygen and other nutrients

reaching the body

47https://www.heart.org/en/health-topics/cholesterol/about-cholesterol/atherosclerosis

48https://www.youtube.com/watch?v=y6QJceOAVY0

49https://www.cvphysiology.com/Hemodynamics/H007

LAMINAR BLOOD FLOW TURBULENT BLOOD FLOW

Constriction of the vessel, or obstruction of the vessel lumen, disrupts laminar flow and leads to turbulent blood flow

Blood flow velocity increases small eddies lead to flow in

directions other than parallel Such current eddies lead to

turbulence Turbulent blood flow is noisy

and can be heard by using a stethoscope placed over the artery

50

Blood flows in layers As the layers extend toward

the vessel interior, their velocity increases

laminar blood flow is silent

https://www.physiologyweb.com/figures/physiology_illustration_Gxr9bSdjRij69DSavoTbjWtiQ44Pw3aM_laminar_versus_turbulent_flow_in_blood_vessels.html

51http://hyperphysics.phy-astr.gsu.edu/hbase/ppois2.html

How do we measure blood pressure?

52https://omronhealthcare.com/products/5-series-upper-arm-blood-pressure-monitor-bp742n/?bvstate=pg:4/ct:r

https://www.indiamart.com/proddetail/manual-blood-pressure-machine-16038117873.html

Laminar and turbulent flow provide the physical basis for the auscultation method of blood pressure measurement

Using a pressure cuff placed over the upper arm (to cause vessel constriction) and a stethoscope placed over the brachial artery

Listen for the noise of turbulent flow when the vessel is constricted)

The sounds heard by this method are referred to as the Korotkoff's sounds.

53https://www.physiologyweb.com/figures/physiology_graph_kOmgHIRVcRNo0zfrBCKzz1dZcNyZkjeC_measurement_of_hydrostatic_blood_pressure.html

https://www.saga.co.uk/magazine/health-wellbeing/conditions/cardiovascular/how-to-monitor-blood-pressure

54https://www.youtube.com/watch?v=UTJvWLi2uCM

SLIPSTREAM

55

https://www.formula1.com/

https://hackernoon.com/the-good-the-bad-and-the-ugly-crypto-2018-ba784bdd2a47

56https://www.youtube.com/watch?v=xdWFulVLOqg

57https://www.youtube.com/watch?v=BQ1xHbr9JIQ

Is blood a Newtonian or non-Newtonian fluid?

What increases blood viscosity? How to prove Bernouli’s equation? How to prove Toricceli’s equation? Can atherosclerosis be cured? Why do oxygen masks drop in planes?

58