For all you geeks out there:

[Nick]

I've been facinated by the physics behind pipe smoking recently. Here are some tidbits of what I've come accross and what I'm looking for:

(Yes, I know I have way too much free time - NOT true btw. I mean I know I'm a state employee, but seriously. Hehehehe)

Puff volume: 50 cc
puff duration: 1.2 sec
rate: 11 puffs/min
flow rate: 2430 cc/min
particle size in pipe smoke: 0.6 – 0.7 micron
static burn rate: 47 mg/min
fire holding capacity: 175 seconds
puff resistance before lighting: 2 mm H2O (Resp. <1)
puff resistance during smoking: 10 - 20mm H2O

Observation: With the laws of thermodynamics in mind, the greater the surface area that the hot smoke is exposed to, the cooler the smoke will be. Therefore, the more open the draw, the cooler the smoke.

Question: Does an open draw create more velocity in the smoke? I.e. does the smoke spend less time in the draught passage with an open draw than with a closed draw?

Question: If the above is true, does that mean that an open draw can create a hotter smoke? Where does the equilibrium lie?

Q: What is the heat absorbtion of briar?
Q:Vulcanite?
Q: Lucite?

Q: does the volume of smoke coming through the pipe effect the amount of heat disapated. I.e. Does a larger the larger “pipe” contain more heat? What I tend to do is pack a pipe my pipes so that the draw is roughly uniform – more open draw=tighter pack.

The Laws of Thermodynamics
Alternative statements that are mathematically equivalent can be given for each law.
• Zeroth law: Thermodynamic equilibrium. When two systems are put in contact with each other, energy and/or matter will be exchanged between them unless they are in thermodynamic equilibrium. Two systems are in thermodynamic equilibrium with each other if they stay the same after being put in contact. The zeroth law is stated as
If A and B are in thermodynamic equilibrium, and B and C are in thermodynamic equilibrium, then A and C are also in thermodynamic equilibrium.
While this is a fundamental concept of thermodynamics, the need to state it explicitly as a law was not perceived until the first third of the 20th century, long after the first three laws were already widely in use, hence the zero numbering. There is still some discussion about its status.
Thermodynamic equilibrium includes thermal equilibrium (associated to heat exchange and parameterized by temperature), mechanical equilibrium (associated to work exchange and parameterized generalized forces such as pressure), and chemical equilibrium (associated to matter exchange and parameterized by chemical potential).
• 1st Law: Conservation of energy. This is a fundamental principle of mechanics, and more generally of physics. In thermodynamics, it is used to give a precise definition of heat. It is stated as follows:
The work exchanged in an adiabatic process depends only on the initial and the final state and not on the details of the process.
or
The heat flowing into a system equals the increase in internal energy of the system minus the work done by the system.

Q=(delta)E+W
Q= heat, E=energy, W= work
• 2nd Law: A far reaching and powerful law, it can be stated many ways, the most popular of which is:
It is impossible to obtain a process such that the unique effect is the subtraction of a positive heat from a reservoir and the production of a positive work.
Specifically,
A system operating in contact with a thermal reservoir cannot produce positive work in its surroundings (Lord Kelvin)
or
A system operating in a cycle cannot produce a positive heat flow from a colder body to a hotter body (Clausius)
The entropy of a closed macroscopic system never decreases (see Maxwell's demon), however a microscopic system may exhibit fluctuations of entropy opposite to that dictated by the second law (see Fluctuation Theorem).
• 3rd Law: This law explains why it is so hard to cool something to absolute zero:
All processes cease as temperature approaches zero.
As temperature goes to 0, the entropy of a system approaches a constant
These laws have been humorously summarised as Ginsberg's theorem: (1) you can't win, (2) you can't break even, and (3) you can't get out of the game.
Or, alternatively: (1) you can't get anything without working for it, (2) the most you can accomplish by working is to break even, and (3) you can only break even at absolute zero.
Or: (1) you can't get out more than you put in (2) even the best-designed machine eventally loses energy and stops (3) you can't get to absolute zero.

[Nick]

update:
flow rate: 2430 cc/min = .6420 GPM
puff resistance before lighting:2 mm H2O (Resp<1) = .1471 mm HG = .0002 atm
puff resistance during smoking: 10 – 20 mm H2O = 1.103 mm Hg = .0026 atm (15 used for conversions)

1atm = 760 mm Hg
1atm = 33.9 ft H2O

33.9 ft H2O = 1033cm H2O

760 mm Hg = 10330 mm H2O

2430 cc/min in a 3.175mm(1/8”) tube = what velocity? 16.78 fps = 201.36 In/sec
5 inch tube = .025 sec
6 = .03 sec
7 = .035 sec
2430 cc/min in a 4 mm (.15748”) tube = what velocity? 10.574 fps = 126.88 in/sec
5 inch tube = .039 sec
6 = .047 sec
7 = .055 sec
2430 cc/min in a 4.7625mm(3/16”) tube = what velocity? 7.549 fps = 90.558
5 inch tube = .055 sec
6 = .066 sec
7 = .077 sec