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The hybrid method, a new method for accurate heat transfer predictions in channels with axially variable heat flux

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Abstract

A new computation method is presented for the accurate determination of temperature fields and heat transfer characteristics for steady forced convection flow in coolant channels with an arbitrary prescribed wall heat flux. The essential feature of this method is that the fluid region is discretized in the section normal to the flow direction. Energy balances set up for each of the elements yield a system of linear first order differential equations with as a sole independent variable an axial distance parameter. This system of equations is solved analytically using a matrix method. The method is illustrated for the case of laminar flow in flat and circular ducts.

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Abbreviations

a :

thermal diffusivity, λ c/ρc p.

[A]:

symmetric tridiagonal matrix of dimensionless transport coefficients, eqs. (19–21)

c p :

specific heat

D :

dimensionless transport coefficient, eq. (16)

d e :

equivalent hydraulic diameter

d e·t :

equivalent thermal diameter

G i :

elementary mass flow rate in an element i

G t :

total mass flow rate

GR i :

reduced elementary mass flow rate, eq. (15)

H :

fluid enthalpy

ΔH :

total fluid enthalpy rise over length of channel

HR i :

dimensionless fluid enthalpy, eq. (10)

L :

heated channel length

N :

number of fluid elements in discretization procedure

Nu :

local Nusselt number, αd e/λ, dimensionless

Pe :

Peclet number, d e u b/a, dimensionless

Q :

heat flow per unit of length

QR i :

dimensionless heat generation term, eq. (17)

q′ :

heat generation per unit of length

q″ :

local heat flux

s i·j :

lateral extent of boundary between adjacent fluid elements i and j

T :

temperature

u :

axial velocity

[VE]:

eigenvector matrix

x :

axial distance coordinate

X :

dimensionless axial distance x/L

y :

wall distance

y 0 :

distance between wall and symmetry line

Δy i :

width of grid element

α :

heat transfer coefficient, eq. (47)

β i·j :

local transport coefficient, eq. (4)

γ i :

eigenvalue, dimensionless

λ :

thermal conductivity of fluid

ρ :

fluid density

av:

averaged over heated channel length

b:

bulk

c:

channel centre, or adiabatic wall

i :

number of fluid element

in:

inlet

w:

wall

x :

axial position

References

  1. Graetz, L., Ann. Phys. Chem. 25 (1885) 337.

    Google Scholar 

  2. Sellars, J. R., M. Tribus and J. S. Klein, Trans. Amer. Soc. Mech. Engrs. 78 (1956) 441.

    Google Scholar 

  3. Siegel, R., E. M. Sparrow and T. M. Hallman, Appl. Sci. Res. A7 (1957) 386.

    MathSciNet  Google Scholar 

  4. Sparrow, E. M., T. M. Hallman and R. Siegel, Appl. Sci. Res. A7 (1957) 37.

    MathSciNet  Google Scholar 

  5. Hsu, C. J., AIChE J. 11 (1965) 690.

    Article  Google Scholar 

  6. Hatton, A. P. and A. Quarmby, Int. J. Heat Mass Transfer 6 (1963) 903.

    Article  Google Scholar 

  7. Lundberg, R. E., P. A. McCuen and W. C. Reynolds, Int. J. Heat Mass Transfer 6 (1963) 495.

    Article  Google Scholar 

  8. Hasegawa, S. and Y. Fujita, Int. J. Heat Mass Transfer 11 (1968) 943.

    Article  Google Scholar 

  9. Chen, J. C. and W. S. Yu, Int. J. Heat Mass Transfer 13 (1970) 667.

    Article  Google Scholar 

  10. Hasegawa, S. and Y. Fujita, 4th Int. Heat Transfer Conf., Paris, (1970) FC 3.4, 1.

  11. Bankston, C. A. and D. M. McEligot, Nucl. Sci. Eng. 37 (1969) 157.

    Google Scholar 

  12. Nijsing, R., Heat Exchange and Heat Exchangers with Liquid Metals, in Lecture Series Nr. 57 on Heat Exchangers, AGARD, Paris 1972.

  13. Kays, W. M., Trans. ASME 77 (1955) 1265.

    Google Scholar 

  14. Grigull, U. and H. Tratz, Int. J. Heat Mass Transfer 8 (1965) 669.

    Article  MATH  Google Scholar 

  15. Buleev, N. I., L. D. El Tsova and C. P. Biryuka, High Temp. 4 (1966) 510.

    Google Scholar 

  16. Nijsing, R. and W. Eifler, Nucl. Eng. Design 4 (1966) 253.

    Article  Google Scholar 

  17. Nijsing, R. and W. Eifler, Thermal Design Aspects of Fuel Rod Bundles with Emphasis on Intersubchannel Mixing, Deutsches Atomforum, Bonn (1971) 126–129.

    Google Scholar 

  18. Nijsing, R. and W. Eifler, A Computation Method for the Steady State Thermohydraulic Analysis of Fuel Rod Assemblies with Single Phase Cooling, to be published.

  19. Nijsing, R. and W. Eifler, Nucl. Eng. Design 23 (1972) 331.

    Article  Google Scholar 

  20. Schneider, P. J., Trans. ASME 79 (1957) 765.

    Google Scholar 

  21. Hsu, C. J., Appl. Sci. Res. 17 (1967) 359.

    Article  MATH  Google Scholar 

  22. Hsu, C. J., Chem. Engng. Sci. 23 (1968) 457.

    Article  Google Scholar 

  23. Hennecke, W., Wärme- und Stoffübertragung 1 (1968) 177.

    Google Scholar 

  24. Hsu, C. J., Int. J. Heat Mass Transfer 13 (1970) 1907.

    Article  MATH  Google Scholar 

  25. Hsu, C. J., AIChE J. 17 (1971) 732.

    Article  Google Scholar 

  26. Zurmühl, R., Matrizen, Springer, Göttingen, p. 144.

  27. Wilkinson, J. H., The Algebraic Eigenvalue Problem, Clarendon Press, Oxford (1965).

    Google Scholar 

  28. Ralston, A. and H. S. Wilf, (ed.), Mathematical Methods for Digital Computers, Wiley & Sons, Inc., New York (1966).

    Google Scholar 

  29. Wilkinson, J. H., Numer. Math. 4 (1962) 354.

    Article  MATH  MathSciNet  Google Scholar 

  30. Rutishouser, H., and H. R. Schwarz, Numer. Math. 5 (1963) 273.

    Article  MathSciNet  Google Scholar 

  31. Galligani, I., A Comparison of Methods for Computing the Eigenvalues and Eigenvectors of a Matrix, EUR 4055 e (1968).

  32. Lancaster, P., Theory of Matrices, Academic Press, New York (1969) p. 96.

    Google Scholar 

  33. Leveque, A., Ann. Mines, Paris — Mém. Sér. 12, 13 (1928) 283.

    Google Scholar 

  34. Kramers, H. and P. J. Kreyger, Chem. Eng. Science 6 (1956) 42.

    Article  Google Scholar 

  35. Bird, R. B., W. E. Stewart and E. N. Lightfoot, Transport Phenomena, John Wiley & Sons, Inc., New York (1960) 363.

    Google Scholar 

  36. Worsøe-Schmidt, P. M., Int. J. Heat Mass Transfer 10 (1967) 541.

    Article  Google Scholar 

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Nijsing, R., Eifler, W. The hybrid method, a new method for accurate heat transfer predictions in channels with axially variable heat flux. Appl. Sci. Res. 28, 401–418 (1973). https://doi.org/10.1007/BF00413080

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