Session: Research Posters

Paper Number: 116409

116409 - Influence of Geometry and Mass on the Heat Transfer Properties of a Casted Heat Sink 

In recent years, manufacturing technologies have advanced, and producing parts with complex geometries is now possible. For example, a proper cooling system must be designed when casting is used in production.  The ability to produce conformal channels has contributed to developing and manufacturing components capable of transferring and dissipating heat more efficiently and effectively. An excellent example of a complex component to be manufactured is the heat sinks used in electric vehicles. Nevertheless, in this area of activity, in addition to optimizing thermal dissipation, it is also critical to reduce the mass of components, which will reduce the mass of the vehicle as well as increase its performance. Geometry and the mass of these heat sinks play an essential role in determining their heat transfer properties. In this context, this study aims to investigate the effects of geometry and mass on the heat transfer properties of a heat sink. The aluminum heat sink under study is composed of a base supporting seven fins. Different geometries and mass of this part were tested. Specifically, the surface finish and roughness of the piece's base, as well as the thickness of its fin support base, were varied, changing the mass of the component. To determine the heat transfer performance of the heat sink, heat flux measurements were conducted using a heat flow sensor. The experiments consist of uniform heating of an aluminum plate by a mica heater, with an accuracy of ± 1 °C. To measure the heat transfer rate, an OMEGA HFS-4 thin film heat flux sensor is mounted at the center of the target surface. The heat sink is placed over the sensor, and several thermocouples are connected to both the heated plate and the heat sink to control the temperature.  The thermocouples and the heat flux sensor are connected to a NI 9213 data acquisition system and the data processing is performed using LabVIEW based software. A closed test chamber was used to avoid external air flow interferences.  The tests were conducted at 50 °C and 90 °C. As a result of reducing the roughness in the contact area by 48% (changing Ra from 0.96 to 0.46 m), the heat transfer coefficient was increased by 52% and 68 % at 90 and 50 °C, respectively. Furthermore, for a similar surface finish, a decrease of 8 % in mass will increase the heat transfer coefficient from 26 to 36 W/m².K at 50 °C, and 44 to 55 W/m².K at 90 °C.

 

Presenting Author: Delfim Soares CMEMS-UMinho - Center for Microelectromechanical Systems, University of Minho

Presenting Author Biography: Assistant Professor at the Department of Mechanical Engineering at the University of Minho since 1998, in the disciplinary area of Materials and Mechanics of Materials. Degree in Metallurgical Engineering from the Faculty of Engineering of the University of Porto (1987) and Doctorate in Mechanical Engineering, area of knowledge of Materials and Mechanics of Materials, from the University of Minho in 1998. The R&D activity is developed within the scope of CMEMS - Center for MicroElectroMechanical Systems, integrating national and international research projects in the areas of Materials Science and Technology, Materials in micro/nano electromechanical systems, design and processing technologies for functional materials and computational modeling from UMinho, from other universities, and the Iberian Nanotechnology Institute (INL). Research activities carried out in the development of new materials, manufacturing technologies and waste treatments. Performs works of metallurgical and thermomechanical characterization of the different materials. The research activity carried out resulted in more than 80 scientific publications as an author / co-author in books, magazines and international conferences.

Authors:

Paulina Capela DEM, University of Minho
Flávia Barbosa MEtRICs – Mechanical Engineering and Resource Sustainability Center
Inês V. Gomes CMEMS-UMinho - Center for Microelectromechanical Systems, University of Minho
Filipe Prior Prifer - Fundição, S.A.
Hélder Puga CMEMS-UMinho - Center for Microelectromechanical Systems, University of Minho
Delfim Soares CMEMS-UMinho - Center for Microelectromechanical Systems, University of Minho
José Carlos Teixeira MEtRICs – Mechanical Engineering and Resource Sustainability Center