nanofluids by quantum mechanics thomas prevenslik discovery bay, hong kong 1
DESCRIPTION
HC Mixing Rules HC extended Maxwell’s rules for electrical to thermal conductivity of macroscopic particles. Applicable to nanoparticles. k eff = Effective k f = Fluid k P = NP = Volume fraction 3TRANSCRIPT
Nanofluids by
Quantum Mechanics
Thomas Prevenslik
Discovery Bay, Hong Kong
1
Background
Nanoparticles (NPs) are thought to increase the thermal conductivity of common solvents.
Transient Hot Wire Method (THWM) tests show enhancements far greater than given by Hamilton &
Crosser (HC) mixing rules.
T. Prevenslik, “Nanofluids by QED Induced Heat Transfer,” IASME/WSEAS 6th Int. Conf. Heat
Transfer, HTE-08, 20-22 August, Rhodes, 2008 2
HC Mixing Rules HC extended
Maxwell’s rules for electrical to thermal conductivity of macroscopic particles. Applicable to nanoparticles.
k
PffP
PfP
f
eff
kkk2kkk2k
kk
keff = Effective
kf = Fluid
kP = NP
= Volume fraction 3
Purpose
4
Show THWM test data may be explained by QED induced heat transfer with the conductivity itself given
by HC mixing rules
HC mixing rules are valid
Thermal conductivity does not increase
QED induced Heat TransferClassically, heat or EM energy is conserved
by an increase in temperature.
But at the nanoscale, QM forbids heat to be conserved by an increase in temperature
because specific heat vanishes.
QED allows heat to be conserved by frequency up-conversion of kT energy to the EM
frequency of the NP which escapes by the emission of nonthermal EM radiation
5
QM Restrictions
cf Dn2 r hfEP
QM induces the creation of photons of wavelength by supplying EM energy to a box
with walls separated upon /2. For a spherical NP of diameter D having refractive index nr > 1:
6
QM restricts the heat content of atoms depending on temperature and EM confinement given by
the Einstein-Hopf relation
NPs have Zero Heat Content
0.00001
0.0001
0.001
0.01
0.1
1 10 100 1000
Wavelength - - microns
Pla
nck
Ene
rgy
- E -
eV
1
kThcexp
hc
E
7NPs
0.0258 eV
QED radiation in NPs
• • • Specific Heat Vanishes
No Temperature change
EMEmission = 2Dnr
Molecular CollisionsNanofluids
Laser/Solar/Supernovae Photons
Residual kT EnergyTribochemistry Thin Films
Joule Heat
NP
8 ASME Micro/Nanoscale Heat / Mass Transfer Int. Conf., Dec. 18-21, 2009 — Shanghai, China
Collisional Heating
9
mkTPpD
32Q 2
C
0.0010.01
0.11
10
1001000
0 20 40 60 80 100
NP Diameter - D - nm
p = 1
p = 0.001
QED
Indu
ced
Hea
t Q
c - n
W..
Collisional Heating
1
10
100
1000
0 20 40 60 80 100
NP Diameter - D - nm
QE
D P
hoto
n E
nerg
y - E
P - eV
1.E+05
1.E+06
1.E+07
1.E+08
1.E+09
1.E+10
1.E+11
1.E+12
QE
D P
hoto
n R
ate
- dN
P /
dt -
s -1
EP
dNP / dtp = 1
dNP / dtp = 0.001
dtdN
EQ PPC
10
QM Heat SinkHeat into NP in the FIR
(10 micron penetration)
Heat out of NP beyond the VUV (1-10 meters penetration)
LTE avoidedNP acts as a QM Heat Sink
VUV penetration >> FIRHeat transfer Penetration
11
AnalysisSTAk SS
NNQ STAkNQQ SSN
VD6N 3
STAkQ Seff
STAQ
DV6kk SN3effS
QQV6 C
12
AS
S
Q
QED Effect on HC Mixing Rules
13
3PffP
PffP
f
S
D1
kkk2kkk2k2k
kk
1
1.1
1.2
1.3
1.4
1.5
0 0.02 0.04 0.06 0.08 0.1
NP Volume Fraction
Rat
io -
k S /
k f
HC
D3>0
D3=0
Conclusions
HC mixing rules give correct effective conductivity of nanofluids.
Disparity with THWM results may be explained with QED induced heating.
Classical heat transfer in NPs requires modification for zero specific heat.
14
Extensions Einstein’s Static Universe
Redshift in cosmic dust means Universe is not expanding and dark energy does not exist.
TribochemistryRubbing of surfaces produces NPs that produce VUV to enhance chemical reactions
Gecko walking on walls and ceilingsSpatulae under on hair tips act as NPs to produce electrostatic attraction
Unification of Static ElectricityRubbing of surfaces produces NPs that charge the surroundings.
Nanocatalysts and Chemiluminescence Gold NPs added to chemical reactants in solution enhance chemical reactions
X-rays from peeling Scotch TapeNPs that form as adhesive tears accumulates charge that at breakdown produces x-rays
Casimir forceBB thermal radiation in gap between parallel plates produces attraction
Etc… 16ASME Micro/Nanoscale Heat / Mass Transfer Int. Conf., Dec. 18-21, 2009 — Shanghai, China