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Heat transfer to wires and cylinders in high‐temperature surroundings
Author(s) -
Sayegh N. N.,
Gauvin W. H.
Publication year - 1981
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450590216
Subject(s) - nusselt number , heat transfer , reynolds number , thermodynamics , mechanics , argon , plasma , range (aeronautics) , materials science , film temperature , limiting , atmospheric temperature range , turbulence , physics , mechanical engineering , atomic physics , composite material , engineering , quantum mechanics
Abstract This paper presents an extension to the case of wires and thin cylinders of a theoretical analysis previously reported by the authors to account for the effects of large temperature differences and large variations of the fluid property on the heat transfer process to a sphere exposed to a gas at very high temperatures. Two concepts were used in this theoretical derivation: (i) the use of a limiting Nusselt number at Re = 0, as derived from the energy equation, and (ii) the use of a reference film temperature for the evaluation of the Reynolds number different from that used for the Nusselt number. The predictions of this analysis are shown to be in excellent agreement with published experimental data in the Re range 0.01 to 40, when the ratio of the wire to the free stream temperature exceeds 0.4. This range of operating conditions is frequently encountered in industrial plasma processing and in certain high‐temperature chemical engineering operations. Measurements in argon and chlorine plasma tailflames with temperature differences exceeding 2000 K are described.