nanofluids by quantum mechanics thomas prevenslik discovery bay, hong kong 1

16
Nanofluids by Quantum Mechanics Thomas Prevenslik Discovery Bay, Hong Kong 1

Upload: asher-allen

Post on 06-Jan-2018

216 views

Category:

Documents


1 download

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 3

TRANSCRIPT

Page 1: Nanofluids by Quantum Mechanics Thomas Prevenslik Discovery Bay, Hong Kong 1

Nanofluids by

Quantum Mechanics

Thomas Prevenslik

Discovery Bay, Hong Kong

1

Page 2: 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

Page 3: Nanofluids by Quantum Mechanics Thomas Prevenslik Discovery Bay, Hong Kong 1

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

Page 4: Nanofluids by Quantum Mechanics Thomas Prevenslik Discovery Bay, Hong Kong 1

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

Page 5: Nanofluids by Quantum Mechanics Thomas Prevenslik Discovery Bay, Hong Kong 1

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

Page 6: Nanofluids by Quantum Mechanics Thomas Prevenslik Discovery Bay, Hong Kong 1

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

Page 7: Nanofluids by Quantum Mechanics Thomas Prevenslik Discovery Bay, Hong Kong 1

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

Page 8: Nanofluids by Quantum Mechanics Thomas Prevenslik Discovery Bay, Hong Kong 1

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

Page 9: Nanofluids by Quantum Mechanics Thomas Prevenslik Discovery Bay, Hong Kong 1

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..

Page 10: Nanofluids by Quantum Mechanics Thomas Prevenslik Discovery Bay, Hong Kong 1

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

Page 11: Nanofluids by Quantum Mechanics Thomas Prevenslik Discovery Bay, Hong Kong 1

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

Page 12: Nanofluids by Quantum Mechanics Thomas Prevenslik Discovery Bay, Hong Kong 1

AnalysisSTAk SS

NNQ STAkNQQ SSN

VD6N 3

STAkQ Seff

STAQ

DV6kk SN3effS

QQV6 C

12

AS

S

Q

Page 13: Nanofluids by Quantum Mechanics Thomas Prevenslik Discovery Bay, Hong Kong 1

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

Page 14: Nanofluids by Quantum Mechanics Thomas Prevenslik Discovery Bay, Hong Kong 1

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

Page 15: Nanofluids by Quantum Mechanics Thomas Prevenslik Discovery Bay, Hong Kong 1

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

Page 16: Nanofluids by Quantum Mechanics Thomas Prevenslik Discovery Bay, Hong Kong 1

Questions & Papers

Email: [email protected]

http://www.nanoqed.org

16