Eventos Anais de eventos
ENCIT 2018
Brazilian Congress of Thermal Sciences and Engineering
POROUS AND NON-POROUS MICROSTRUCTURED SURFACES FOR BOILING HEAT TRANSFER APPLICATIONS
Submission Author:
Leonardo Manetti , MS
Co-Authors:
Leonardo Manetti, Igor Seicho Kiyomura, Elaine Maria Cardoso
Presenter: Leonardo Manetti
doi://10.26678/ABCM.ENCIT2018.CIT18-0719
Abstract
In the last decades, the need for more efficient and compact heat exchangers, especially in microelectronics, and products with high thermal load has been motivating the research on new technics for increasing the boiling heat transfer. The heating surface can be modified by using random micro- or nano-size cavities, porous structure, or protrusions that enlarge the effective area for heat transfer. In this context, we analyze modified heating surfaces consisting of micro-fin array surfaces or metal foams of nickel (Ni), copper (Cu) or stainless steel (SS). All surfaces were submitted to metallographic (stereoscopic and scanning electron microscopy), DI-water droplet dynamic, wettability and thermal image analyses to obtain the wall-temperature profile. It was possible to find out details about the surfaces morphology such as porous size, porous per inches (PPI), and porosity. Furthermore, the DI-water droplet dynamic showed that the stainless steel porous surface has a superhydrophilic behavior; the others surfaces tested, even the open cell metal foams, showed a non-wetting behavior. The infrared thermography analysis showed that the DI-water droplets on Cu foam surface and SS foam surface heat faster than that on the plain surface; however, in the Ni foam surface, the droplet is slowly heated. The thermal behavior is a function of the wettability and absorption behavior of the surfaces (capillary wicking behavior).
Keywords
heating surface, porous, foam, micro-fin surface, pool boiling
