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ISSN Online: 2377-424X

ISBN Print: 0-85295-345-3

International Heat Transfer Conference 10
August, 14-18, 1994, Brighton, UK

THE ROLE OF THICKNESS AND THERMAL EFFUSIVITY IN POOL BOILING CHF IN HIGHLY-WETTING LIQUIDS

Get access (open in a dialog) DOI: 10.1615/IHTC10.4780
pages 183-188

Résumé

Experimental studies have shown that the geometric and thermophysical properties of the heater significantly influence the critical heat flux (CHF). While the thermal activity parameter δ√(ρcpλ) has been found to correlate this variation very effectively, no physical explanation for its success is as yet available. A conceptual CHF model, emphasizing both the role of transient radial conduction within the heater and the relationship between the heater surface temperature and CHF, is proposed to account for this dependence. A finite element analysis is used to investigate the effect of heater and substrate thermal properties on the temperature distribution at CHF. The numerical results show that the thermal activity parameter is associated with radial transient conduction in the heater and that the presence of a substrate will augment the critical heat flux on thin heaters with low thermal activity values.