Title: Weakly nonlocal continuum physics
1Weakly nonlocal continuum physics the role of
the Second Law Peter Ván HAS, RIPNP,
Department of Theoretical Physics
- Introduction
- Second Law
- Weak nonlocality
- Liu procedure
- Classical irreversible thermodynamics
- Ginzburg-Landau equation
- Discussion
2Nonequilibrium thermodynamics
science of temperature
Thermodynamics science of macroscopic
energy changes
general framework of any Thermodynamics
(?) macroscopic continuum theories
- General framework
- Second Law
- fundamental balances
- objectivity - frame indifference
reversibility special limit
3Thermo-Dynamic theory
Evolution equation
1 Statics (equilibrium properties)
2 Dynamics
41 2 closed system
S is a Ljapunov function of the equilibrium of
the dynamic law
Constructive application
force
current
5Classical evolution equations balances
constitutive assumptions
Fourier heat conduction
Dgt0
Not so classical evolution equations balances
(?) constitutive assumptions
Ginzburg-Landau equation relaxation
nonlocality
lgt0, kgt0
6Nonlocalities
Restrictions from the Second Law. change of the
entropy current change of the entropy
Change of the constitutive space
7Basic state, constitutive state and constitutive
functions
Heat conduction Irreversible Thermodynamics
1)
- basic state
- (wanted field T(e))
Fourier heat conduction
But
Guyer-Krumhansl
Cattaneo-Vernote
???
8Fluid mechanics
2)
Local state Euler equation
Nonlocal extension - Navier-Stokes equation
But
Korteweg fluid
9Internal variable
3)
A) Local state - relaxation
B) Nonlocal extension - Ginzburg-Landau
e.g.
10Irreversible thermodynamics traditional
approach
- basic state
- constitutive state
- constitutive functions
J
Solution!
currents and forces
Heat conduction ae
11Second Law
basic balances
- basic state
- constitutive state
- constitutive functions
Second law
(universality)
Constitutive theory balances are constraints
Method Liu procedure
12Liu procedure
LEMMA (FARKAS, 1896) Let Ai ? 0 be independent
vectors in a finite dimensional vector space V, i
1...n, and S p ?V pAi 0, i
1...n. The following statements are equivalent
for a b ? V (i) pB 0, for all p ? S. (ii)
There are non-negative real numbers ?1,..., ?n
such that
Vocabulary elements of V independent
variables, V the space of independent
variables, Inequalities in S
constraints, ?i Lagrange-Farkas multipliers.
13Usage
A1
B
14Proof S is not empty. In fact, for all k, i
?1,..., n there is a such that pkAk 1 and
pkAi 0 if i ? k. Evidently pk?S for all
k. (ii) ? (i)
if p? S. (i) ? (ii) Let S0 y?V
y Ai 0, i 1...n. Clearly Ø? S0 ? S. If y?
S0 then -y is also in S0, therefore yB 0 and
-yB 0 together. Therefore for all y? S0 it is
true that yB 0. As a consequence B is in the
set generated by Ai, that is, there are real
numbers ?1,..., ?n such that B .
These numbers are non- negative, because with
the previously defined pk? S, is
valid for all k. QED
15Vocabulary Final equality Liu
equations Final inequality residual
(dissipation) inequality.
16Usage
17Irreversible thermodynamics beyond traditional
approach
- basic state
- constitutive state
- constitutive functions
Liu and Müller validity in every time and
space points, derivatives of C are independent
18A) Liu equations
solution
B) Dissipation inequality
Spec Heat conduction ae
A)
B)
19What is explained The origin of Clausius-Duhem
inequality - form of the entropy current -
what depends on what Conditions of
applicability!! - the key is the constitutive
space
Logical reduction the number of independent
physical assumptions! Mathematician ok
but Physicist no need of such thinking, I
am satisfied well and used to my analogies no
need of thermodynamics in general Engineer con
sequences?? Philosopher
Popper, Lakatos excellent, in this way we can
refute
20Weakly nonlocal internal variables
Ginzburg-Landau (variational)
- Variational (!)
- Second Law?
-
21Ginzburg-Landau (thermodynamic, relocalized)
constitutive state space
constitutive functions
local state
Liu procedure (Farkass lemma)
?
22current multiplier
isotropy
23Ginzburg-Landau (thermodynamic, non relocalizable)
state space
constitutive functions
Liu procedure (Farkass lemma)
24- Discussion
- Applications
- heat conduction, one component fluid
(Schrödinger-Madelung, ), two component fluids
(sand), complex Ginzburg-Landau, , weakly
non-local statistical physics, - ? Cahn-Hilliard, Korteweg-de Vries, mechanics
(hyperstress), - Dynamic stability, Ljapunov function???
- Universality independent on the micro-modell
- Constructivity Liu force-current systems
- Variational principles an explanation
- Second Law
25References Discrete, stability T. Matolcsi
Ordinary thermodynamics, Publishing House of the
Hungarian Academy of Sciences, Budapest,
2005. Liu procedure Liu, I-Shih, Method of
Lagrange Multipliers for Exploitation of the
Entropy Principle, Archive of Rational Mechanics
and Analysis, 1972, 46, p131-148. Weakly
nonlocal Ván, P., Exploiting the Second Law in
weakly nonlocal continuum physics, Periodica
Polytechnica, Ser. Mechanical Engineering, 2005,
49/1, p79-94, (cond-mat/0210402/ver3). Ván, P.
and Fülöp, T., Weakly nonlocal fluid mechanics -
the Schrödinger equation, Proceedings of the
Royal Society, London A, 2006, 462, p541-557,
(quant-ph/0304062). Ván, P., Weakly nonlocal
continuum theories of granular media
restrictions from the Second Law, International
Journal of Solids and Structures, 2004, 41/21,
p5921-5927, (cond-mat/0310520).
26Thank you for your attention!