A new approach in the modeling of the critical heat flux and enhancement techniques

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Abstract

Understanding of the boiling crisis mechanism is still incomplete; starting from experimental observations of the dry spots during boiling crisis, a new approach to bridge this gap is proposed. The thermal instabilities occurring at the triple contact lines where evaporation is intense are focused on. The “dry-out” phenomenon is local; it depends on the local conditions at a very tiny evaporating meniscus adjacent to the heating surface. The enhancing role of EHD for CHF is studied through a stability analysis of the meniscus subjected to an electrical-field. The equations describing the evaporating system are modified to account for the effect of electrical forces. We have found that the electrical-field delays thermocapillary instability. Our analysis revealed that the onset of instability is very sensitive to the interface deformation.

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