Transcript Viscosity - Center for Polymer Studies

Viscosity
for students of Physics
Isaac Newton studied
viscosity
Tom Ramsey
Mentor High School
Mentor OH 44060
[email protected]
Viscosity: Connecting with Chemistry and Biology
Does air resistance increase as v or v2???
Air resistance produced by collisions of gas molecules
Air Resistance Increases with Temp
Proportional to v for slow speeds
Proportional to v2 for higher speeds
Because of turbulence
Reynolds number provides dividing line
Visc.smd
Viscosity/friction in a fluid
Decreases with increasing Temp
Produced by decreasing
intermolecular forces
Non-Newtonian Fluids
Viscosity_liquid.smd
3 oils/5 temp
Applications
Bernoulli’s equation
Non-newtonian fluids
Pouiselle’s Equation:
Q ~ r4
Alt. Models:fractals,
percolation
Dr. Jean Leonard Marie
Poiseuille Checks his heart
Introduction
Provides a connection between math,chemistry
Biology and Physics
Provides students a chance to look at
alternate scientific models.
Provides a molecular explanation as an alternate
To the usual continous model
Intended Audience
AP,Honors, Regular Physics
Builds on what students have learned
In other classes
Adjustments/Adaptations
None required-all levels of Physics
can handle
Placement in Curriculum
After kinematics and dynamics
Some concepts such as Pressure were
learned in Chem
Goals and Objectives
Determine the relationship between
temp and viscosity for both gases and
liquids
Compare different models for viscosity
understand the usefulness of Reynold’s number
As a criterion for distinguishing turbulent and nonturbulent flow.
Give reports on the application of viscosity to other fields such
As Biology, Chemistry and Engineering
Time Line
Day 1: Air Resistance(Wet Lab)
Coffee Filter Lab
•F a v or F a v2 ????
•Cedar Point/Six Flags
•Cold Air+Warm Air
Day 2: Macro Micro(Computer)
Visc.smd
•F a v (Stokes)
•F=DP/Dt * A
h versus m,T
Day 3: Kinetic Karnival Video:
“Viscosity”
Lab:Marbles in Oil(Wet)
Non-NewtonianFluids (Corn
Starch,Slime etc).
h versus T for liquid
Day 4: liquid.smd(Computer)
H increases with temp in gas(collisions
increase)but decreases in liquid(
intermolecular forces)
Demo: KMn04 in warm H2O(wet)
Day 5 Bernoulli’s Equation
Continuity Equation
Endless numbers of examples
From groundhogs, to baseballs to
airplane wings
Day 6 Poiseulle’s Equation /Heart
Q ~ r4
Relate the velocity profile of a fluid in a
pipe to Poiseulle’s Equation
Day 7 bernoulli_xtal.smd
Airfoil crystal
Using SMD students build a crystal in
the shape of an airfoil
Day 8: Student Reports
5 minute seminar
Examples from other
sciences/enginering
Resources
1 computer per 2/3 students
Smd program with viscosity files
for liquid and gases.
Standard lab equipment(hot plates,
graduates, coffee filters,metersticks
for wet labs)
Bibliography
Websites:
Transtronics:Viscosity Basics
Fluid Dyanmics Online Textbook
Vicosity of Lava Flows
Wolfram Research(Mathematica) Navier Stokes Equation
Mathematica model of Galileo's Experiment
BU software/curricular material
References:
Physics by Douglas Giancoli 3rd
Schaum’s Outline Series:
Fluid Dynamics
Solving Problems in Fluid Mechanics
Vol2 by JF Douglas 1967
Life’s Devices by Steven Vogel
Princeton University Press
ISBN0691024189