This paper reviews advanced heat transfer devices utilizing advanced manufacturing technologies, including well-established thermal management applications. Several factors have recently contributed to developing novel heat transfer devices. One of the potential technologies revolutionizing the field of energy conversion is additive manufacturing (AM), colloquially known as three-dimensional (3D) printing. This technology permits engineers to develop a product with a high level of freeform features both internally and externally within a complex 3D geometry. Among different AM approaches, selective laser melting (SLM) is a well-used technique for developing products with a lower cost-to-complexity ratio and quicker time production compared to other manufacturing processes. The integration of SLM technology into heat exchangers (HXs) and heat sinks (HSs) has a strong potential, especially to fabricate customized and complex freeform shapes. The aim of this research is to review the advancement in design complexities of different industrial heat transfer devices incorporating metal SLM fabrication. The review is not meant to put a ceiling on the AM process, but to enable engineers to have an overview of the capabilities of SLM technology in the field of thermal management applications. This review presents the opportunities and challenges related to the application of SLM technology in connection to novel HXs and HSs, as well as heat pipes (HPs). The latter are passive heat transfer devices utilized in many thermal control applications, especially related to electronics cooling and energy applications.

The utilization of selective laser melting technology on heat transfer devices for thermal energy conversion applications: A review

https://eps.utk.edu/faculty/perfect/Papers/Perfect%20et%20al.%20(2014).pdf

Neutron imaging of hydrogen-rich fluids in geomaterials and engineered porous media: A review

Characterization of capillary performance of composite wicks for two-phase heat transfer devices

Experimental investigation on capillary force of composite wick structure by IR thermal imaging camera

Metal 3D-printed wick structures for heat pipe application: Capillary performance analysis

A new hybrid bi-modal wick structure was designed and fabricated in this study with the objective to simultaneously enhance performance in capillary pumping, permeability and evaporative heat transfer. Utilizing substrates with large pores and sintered powders, a highly integrated bi-modal wick structure was created with small pores lining the walls of the large pores. This unique structure can be tailored to a number of different configurations, including uniform, radial and axially varied pore morphologies. Tests of heat pipes containing the bi-modal wick structure in various configurations revealed increases in effective thermal conductivity by as much as 400% as compared to baseline heat pipes containing monolithic wick materials such as copper mesh.

Design and fabrication of hybrid bi-modal wick structure for heat pipe application

This study examines the enhancement of heat pipe thermal performance through the employment of composite wicks Wicks were fabricated from a biporous structure comprised of fine nickel metal powders sintered onto layers of coarse pore copper mesh Wick structures were designed to explore the effects of both enhanced evaporation heat transfer at the liquid/vapor interface and the extension of the capillary limit A number of composite wick heat pipe configurations were fabricated and tested to assess performance improvements in comparison to conventional designs Horizontal, gravity-assisted, and against-gravity tests were conducted to determine whether these designs were orientation-dependent At various heat inputs, some configurations achieved thermal performance levels greater than three times higher than those of conventional heat pipes During against-gravity tests, virtually all composite designs exhibited improved performance over the conventional heat pipe at all heat inputs These results clearly

Development of Composite Wicks for Heat Pipe Performance Enhancement

A new nickel-based porous structure, exhibiting a bi-modal pore size distribution, has been developed through the combination of nickel foam (INCOFOAM) with sintered nickel filamentary powder (T255). Sintering was carried out in the 900–980 °C temperature range in a vacuum environment. These bi-modal nickel samples were examined for their microstructure, hydraulic behaviour including capillary head and permeability, specific surface area (SAA), and overall porosity. The incorporation of a layer of sintered nickel filamentary powder (T255) onto the nickel foam was shown to increase both the specific surface area and capillary pumping pressure of the foam, while simultaneously maintaining high porosity and liquid permeability. Both the sintering temperature and the degree of nickel powder coverage were determined to be critical factors contributing to the properties of these bi-modal nickel porous structures.

George Franchi

Papers

Design and fabrication of hybrid bi-modal wick structure for heat pipe application

Development of Composite Wicks for Heat Pipe Performance Enhancement

Characterization of porous bi-modal Ni structures