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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-421-2

International Heat Transfer Conference 15
August, 10-15, 2014, Kyoto, Japan

Natural Convection around a Pulsating Line Heat Source

Get access (open in a dialog) DOI: 10.1615/IHTC15.ncv.009258
pages 5231-5244

Abstract

Laminar free convection and heat transfer due to a pulsating line heat source are studied experimentally and numerically. The results are also compared with the predictions of an analytical model. A long platinum wire, which is submerged in a large pool of water, is subjected to a periodic Joule heating. The frequency response of the wire is studied in the range 0.01 Hz ???? f ???? 1000 Hz. A very good agreement between experimental and numerical results, particularly at moderate frequencies (0.5-100 Hz), is observed; both of them are also roughly consistent with the predictions of analytical model. Moreover, the time evolution of the fluid temperature and also the vertical component of the velocity at different positions above the wire are analyzed. The results show that the temperature in the fluid oscillates with the same frequency as the input heat. However, the amplitude of the oscillations decreases with both the frequency and the distance from the wire. This attenuation is proportional to f -1/3 (instead of f -1/2 in the case of a pure diffusion mechanism) in the region immediately adjacent to the wire.