1. Review of ChE 231 - Fluid Mechanics
Source Models
Review of ChE Fluid Mechanics
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2. Overview Sources Flow of Escaping Liquids In Class Example Steady Flow
Unsteady Flow
Flow through Pipes
In Class Example
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3. Source Models
We have been talking about hazardous materials being released in the work environment. Most of these releases are through spills or leaks of liquids or vapors.
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4. Places Where Leaks Can Occur
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5. Leaks can be either liquid or vapor depending on location
Today we will talk about liquids
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6. Steady Flow of Liquid through Hole
PG is very high so you can ignore pressure due to height of liquid
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7. Steady Flow of Liquid through Hole
Derive relationship on the board
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8. Overview Sources Flow of Escaping Liquids In Class Example Steady Flow
Unsteady Flow
Flow through Pipes
In Class Example
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9. Unsteady flow of liquid through a hole
Now consider the case when PG is not so high to keep a steady flow and we need to account for height
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10. Unsteady flow of liquid through a hole
Now derive relationship on Board
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11. Overview Sources Flow of Escaping Liquids In Class Example Steady Flow
Unsteady Flow
Flow through Pipes
In Class Example
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12. Liquid flow through pipes
In many cases a pipe is sheared and we need to calculate the flow through a pipe
For flow through a pipe the mechanical energy balance becomes (incompressible fluids)
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13. Liquid flow through pipes
L is length of pipe, d is diameter needs to be same units
f is Fanning friction factor
Found graphically or by equation
Eq Laminar flow
Eq Colebrook Eq – turbulent flow
Eq for ‘fully developed” turbulent flow
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14. Liquid flow through pipes
To account for elbows, fittings, etc use Table 4-2
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15. Liquid flowing through a pipes
Example 4-3 demonstrates use
Often iterative solution
Guess a value for the friction factor, f
Determine average velocity from MEB
Determine Reynolds number, Re
Compute f from Colebrook equation, Eq. 4-25
Iterate until value of f converges
Check Re to assure in fully developed turbulent region (I.e. Colebrook equation is valid)
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