Abstract
Measurements have been made by the comparison method for the effective thermal conductivity of dispersed materials which consist of substances with different thermal conductivities. The applicability of existing predicting formulae is discussed in detail as comparing their predicted values with the present data. A new predicting formula is proposed through analyzing the experimental data, the numerical results, and also the data obtained with the electrolytic-bath. It is found that the proposed formula has a wider range of applicability than that of previously reported ones.
Zusammenfassung
Die effektive Wärmeleitfähigkeit disperser Systeme, die aus Materialien mit verschiedenen Wärmeleitfähigkeiten bestehen, wurde mit einer Vergleichsmethode experimentell bestimmt. Vorhandene Formeln wurden im Detail erörtert und ihre Werte mit den Meßwerten verglichen. Eine neue Gleichung wird vorgeschlagen durch Analyse der experimentellen Daten, der numerischen Werte und auch der mit dem elektrolytischen Bad erhaltenen Ergebnisse. Diese neue Gleichung hat einen größeren Anwendungsbereich als die bisherigen.
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Abbreviations
- a, b, c:
-
side lengths of parallelopiped particle along main axes (a⩾ b⩾ c)
- d:
-
diameter of test specimen
- K:
-
shape factor defined by Eq. (14)
- L:
-
length defined by Eq.(13)
- n:
-
experimental constant
- t:
-
thickness of test specimen
- λ:
-
thermal conductivity
- ϕ:
-
volumetric fraction of discontinuous phase
- ψ:
-
sphericity defined by Eq. (8)
- c:
-
continuous phase
- d:
-
discontinuous phase
- e:
-
effective value
- *:
-
non-dimensional value
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Yamada, E., Ota, T. Effective thermal conductivity of dispersed materials. Wärme- und Stoffübertragung 13, 27–37 (1980). https://doi.org/10.1007/BF00997630
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DOI: https://doi.org/10.1007/BF00997630