Liquid-liquid heat exchangers that operate in marine environments are susceptible to biofouling, which decreases the overall heat exchange between hot and cold liquids by increasing the conduction resistance. Recently, micro/nanostructured oil-impregnated surfaces have been shown to significantly reduce biofouling. However, their potential as a heat exchanger material has not been studied.
View Article and Find Full Text PDFPhase-change condensation is commonplace in nature and industry. Since the 1930s, it is well understood that vapor condenses in filmwise mode on clean metallic surfaces whereas it condenses by forming discrete droplets on surfaces coated with a promoter material. In both filmwise and dropwise modes, the condensate is removed when gravity overcomes pinning forces.
View Article and Find Full Text PDFDue to recent advances in nanofabrication, phase-change condensation heat transfer has seen a renaissance. Compared to conventional heat transfer surfaces, nanostructured surfaces impregnated with chemically matched lubrication films (hereinafter referred to as "nanostructured lubricated surfaces") have been demonstrated to improve vapor-side phase-change condensation heat transfer by facilitating droplet nucleation, growth, and departure. While the presence of nanoscale roughness improves performance longevity by stabilizing the lubrication film capillary forces, such enhancement is short-lived due to the eventual loss of lubrication oil by the departing droplets.
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