Thermal conductivity by a pulse-heating method: Theory and experimental apparatus
Anno: 1990
Autori: Righini F., Bussolino GC., Rosso A., Roberts R.B.
Affiliazione autori: CNR Istituto di Metrologia
Abstract: A new dynamic technique for the measurement of thermal conductivity at high temperatures has been developed at the IMGC. The specimen is brought to high temperatures with a current pulse; during cooling the heat content is dissipated by radiation and by conduction. The differential equation describing this process contains terms related to the heat capacity, the hemispherical total emittance, and the thermal conductivity of the material. If the first two properties are determined using the same specimen during subsecond pulse heating experiments, thermal conductivity may be evaluated by accurate measurements of the round-shaped temperature profiles established on the specimen during cooling. High-speed scanning pyrometry makes possible accurate measurements of temperatures and of temperature derivatives (with respect to space and time), which enables the differential equation describing the power balance at each point of the specimen to be transformed into a linear equation of the unknown thermal conductivity. A large overdetermined system of linear equations is solved by least-squares techniques to obtain thermal conductivity as a function of temperature. The theory underlying the technique is outlined, the experimental apparatus is described, and details of the measurement technique are given.
DOI: 10.1007/BF01184333
Giornale/Rivista: INTERNATIONAL JOURNAL OF THERMOPHYSICS
Volume: 11 (4) Da Pagina: 629 A: 641
Parole chiavi: dynamic measurements; high temperature; scanning pyrometry; thermal conductivityDOI: 10.1007/BF01184333Citazioni: 21dati da “WEB OF SCIENCE” (of Thomson Reuters) aggiornati al: 2024-04-21Riferimenti tratti da Isi Web of Knowledge: (solo abbonati) Link per visualizzare la scheda su IsiWeb: Clicca quiLink per visualizzare la citazioni su IsiWeb: Clicca qui