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Numerical simulation of forced convection in a duct subjected to microwave heating

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Abstract

In this paper, forced convection in a rectangular duct subjected to microwave heating is investigated. Three types of non-Newtonian liquids flowing through the duct are considered, specifically, apple sauce, skim milk, and tomato sauce. A finite difference time domain method is used to solve Maxwell’s equations simulating the electromagnetic field. The three-dimensional temperature field is determined by solving the coupled momentum, energy, and Maxwell’s equations. Numerical results show that the heating pattern strongly depends on the dielectric properties of the fluid in the duct and the geometry of the microwave heating system.

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Abbreviations

A :

area (m2)

C p :

specific heat capacity (J/(kg K))

c :

phase velocity of the electromagnetic propagation wave (m/s)

E :

electric field intensity (V/m)

f :

frequency of the incident wave (Hz)

h :

effective heat transfer coefficient (W/(m2 K))

H :

magnetic field intensity (A/m)

L :

standard deviation of temperature (°C)

k :

thermal conductivity (W/(m K))

m :

fluid consistency coefficient, (Pa sn)

n :

flow behavior index

N t :

number of time steps

p :

pressure (Pa)

q :

electromagnetic heat generation intensity (W/m3)

Q :

volume flow rate (m3/s)

T :

temperature (°C)

t :

time (s)

tan δ:

loss tangent

w :

velocity component in the z direction (m/s)

W :

width of the cavity (m)

ZTE :

wave impedance (Ω)

η:

apparent viscosity (Pa s)

ε:

electric permittivity (F/m)

ɛ′:

dielectric constant

ɛ′′:

effective loss factor

λ g :

wave length in the cavity (m)

μ:

magnetic permeability (H/m)

ρ:

density (kg/m3)

σ:

electric conductivity (S/m)

τ:

instantaneous value

∞:

ambient condition

0:

free space, air

inc:

incident plane

in:

inlet

x, y, z :

coordinate system of the applicator

X, Y, Z :

coordinate system of the microwave cavity

References

  1. Dibben DC, Metaxas AC (1995) Time domain finite element analysis of multimode microwave applicators loaded with low and high loss materials. In: Proceedings of the international conference on microwave and high frequency heating, vol 1–3, no. 4

  2. De Pourcq M (1985) Field and power density calculation in closed microwave system by three-dimensional finite difference. IEEE Proc 132(11):361–368

    Google Scholar 

  3. Jia X, Jolly P (1992) Simulation of microwave field and power distribution in a cavity by a three dimensional finite element method. J Microw Power Electromagn Energy 27(1):11–22

    Google Scholar 

  4. Anantheswaran RC, Liu L (1994) Effect of viscosity and salt concentration on microwave heating of model non-Newtonian liquid foods in a cylindrical container. J Microw Power Electromagn Energy 29(2):119–126

    Google Scholar 

  5. Zhang Q, Jackson TH, Ungan A (2000) Numerical modeling of microwave induced natural convection. Int J Heat Mass Transf 43:2141–2154

    Article  MATH  Google Scholar 

  6. Webb JP, Maile GL, Ferrari RL (1983) Finite element implementation of three dimensional electromagnetic problems. IEEE Proc 78:196–200

    Google Scholar 

  7. Ayappa KG, Davis HT, Davis EA, Gordon J (1992) Two-dimensional finite element analysis of microwave heating. AIChE J 38:1577–1592

    Article  Google Scholar 

  8. Liu F, Turner I, Bialkowski M (1994) A finite-difference time-domain simulation of power density distribution in a dielectric loaded microwave cavity. J Microw Power Electromagn Energy 29(3):138–147

    Google Scholar 

  9. Zhao H, Turner IW (1996) An analysis of the finite-difference time-domain method for modeling the microwave heating of dielectric materials within a three-dimensional cavity system. J Microw Power Electromagn Energy 31(4):199–214

    Google Scholar 

  10. Zhang H, Taub AK, Doona IA (2001) Electromagnetics, heat transfer and thermokinetics in microwave sterilization. AIChE J 47:1957–1968

    Article  Google Scholar 

  11. Zhang H, Datta AK (2000) Coupled electromagnetic and thermal modeling of microwave oven heating of foods. J Microw Power Electromagn Energy 35(2):71–85

    PubMed  Google Scholar 

  12. Patankar SV (1980) Numerical heat transfer and fluid flow. Hemisphere, New York

    MATH  Google Scholar 

  13. Cheng DK (1992) Field and wave electromagnetics, 2nd edn. Addison-Wesley, New York

    Google Scholar 

  14. Mur G (1981) Absorbing boundary conditions for the finite difference approximation of the time domain electromagnetic field equations. IEEE Trans Electromag Compat EC-23:377–382

    Google Scholar 

  15. Yee KS (1966) Numerical solution of initial boundary value problem involving Maxwell’s equations in isotropic media. IEEE Trans Antennas Propagation 14:302–307

    Article  Google Scholar 

  16. Kunz KS, Luebbers R (1993) The finite difference time domain method for electromagnetics. CRC, Boca Raton

    Google Scholar 

  17. Zhang Q (1998) Numerical simulation of heating of a containerized liquid in a single-mode microwave cavity. MS thesis, Indiana University-Purdue University at Indianapolis

Download references

Acknowledgements

The authors acknowledge with gratitude a USDA grant that provided support for this work and the assistance of the Food Rheology Laboratory at North Carolina State University. The calibrations of the fluid consistency coefficients and the flow behavior indexes for the non-Newtonian liquids considered in this study by Ms. S. Ramsey are greatly appreciated.

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Correspondence to A. V. Kuznetsov.

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Zhu, J., Kuznetsov, A.V. & Sandeep, K.P. Numerical simulation of forced convection in a duct subjected to microwave heating. Heat Mass Transfer 43, 255–264 (2007). https://doi.org/10.1007/s00231-006-0105-y

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  • DOI: https://doi.org/10.1007/s00231-006-0105-y

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