ATOC 4720: class 16 Entropy Entropy Generalized statement of the Second Law of thermodynamic...
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Transcript of ATOC 4720: class 16 Entropy Entropy Generalized statement of the Second Law of thermodynamic...
ATOC 4720: class 16ATOC 4720: class 16
Entropy Entropy Generalized statement of the Second Generalized statement of the Second
Law of thermodynamicLaw of thermodynamic Atmospheric aerosolAtmospheric aerosol Effects on atmospheric phenomenaEffects on atmospheric phenomena
Carnot cycle: 4 stepsCarnot cycle: 4 steps
Begins at A
Q1
Q2
Heat is transferred from warmer (H) to colder (c) body
Efficiency:
Hot to cold:Heat can not by itself transfer from cold to hot
EntropyEntropy
The ratio Stays the same no matter
Which isotherm is chosen in passing from one adiabat to anotoher. Therefore,
Is a measureof the difference between the two adiabats; It is called the difference in Entropy (S).
We define:
As the increase in entropy S.Unit mass:
The first law of thermodynamics:
We can derive that:
Transformations in which the entropy remains constant (and therefore potential Temperature remains constant) are called Isentropic.
T-entropy (S) diagram T-entropy (S) diagram
Work done
Generalized statement of the second Generalized statement of the second law of thermodynamicslaw of thermodynamics
Up to now: ideal reversible, equilibrium
1. There exists a function of state for a body called entropy s;
2. S may change (due to thermal conduction) Or as internal change
3.
4. For reversible process
For nonreversible:
Reversible:
Nonreversible:
3. Aerosols3. Aerosols
Total concentrationTotal concentration
Size spectraSize spectra