Introduction to stress and surface tension

CHEE 3363 Spring 2014 Handout 03

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Learning objectives for lecture

1. "

2. "

3. "

4. "

5.

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δA

δFn

δFt

δF

Normal stress:

Tangential or shear stress

stress tensor T

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Stress is a tensor"

"

z

δFx

δFy

δFz

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z

τxy

τxz

σxx

δAx δAx

Calculation of force on a surface

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δl

δα

δx

δy

δFx

δv

Force

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"

- "

"

"

"

- Units:!

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t w

μF = 25 lbf."

= 3 ft/s.

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W V h =

L = w ×

10-5 lbf-s/ft2."

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W Lθ

μ V h "

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SGL D =

μ m

"V m.

h

p0

Force Fx

Force F

F

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Surface tension!

"

!

"

"

"

θ < 90°θ > 90°

θ

z∆h

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