Discipline: Technology and Engineering
Subcategory: Civil/Mechanical/Manufacturing Engineering
Alexandra Aucoin - Nicholls State University
Co-Author(s): Stephen Akwaboa, Southern University, LA; Patrick F. Mensah, Southern University, LA
As technology advances and electronic chips become more compact, thermal power and heat fluxes from the chip’s surface have increased drastically, presenting a daunting challenge in the removal of the heat generated in the chips and maintaining chip temperature below 85 oC. Conventional cooling techniques are increasingly becoming inadequate in dealing with these high cooling demands. Current cooling technologies indicate that microchannel-base forced convention and phase-change cooling techniques are capable of achieving very high heat removal rates. Heat transfer performance of an unpatterned and finned horizontal aluminum surface simulating a typical electronic chip in a pool of Novec 7100 is studied. Using ANSYS Design Modeler, the plane aluminum heat sink measuring 10mm x 13mm x 3mm was modeled. The Rensselear Polytechnic Institute (RPI) model, in ANSYS Fluent, is used to model nucleate boiling on surfaces immersed in Novec 7100. The RPI model partitions the wall heat flux into convective heat flux, quenching heat flux and evaporative heat flux. The model is able to predict the wall temperature and the partitioning of the wall heat flux with superb accuracy. The results show that the convective heat flux is predominant at low wall superheat (T < 7 K). As wall superheat increases, the evaporative heat flux increases monotonically. The quenching heat flux, however, increases up to a maximum and then begins to decrease, lending credence to the existence of critical heat flux (CHF). The CHF for the unpatterned surface is about 13 W/cm2, while that for the finned is about 40 W/cm2 for saturation pool boiling. The results show that the presence of fins increased the CHF considerably, signifying higher heat transfer in the heat sink. The work further shows that Novec 7100 has superior thermal properties and holds great promise as a coolant for high-tech electronic devices for thermal management. In the future, we hope to perform additional parametric studies with subcooling, explore 3D printing possibilities, and test different fin geometries, such as circular fins, keeping the wetted surface area of the fins constant. References: [1] Pal A, Joshi YK, Beitelmal MH, Patel CD and Wenger TM. Design and performance evaluation of a compact thermosyphon. IEEE Transactions on Components and Packaging Technologies. 2002; 25(4): 601-607. [2] Maydanik YF, Vershinin SV, Korukov MA and Ochterbeck JM. Miniature loop heat pipes-a promising means for electronics cooling. IEEE Transactions on Components and Packaging Technologies. 2005; 28(2):290-296 [3] Jiang L, Mikkelsen J, Koo JM, Huber D, Yao S, Zhang L, et al. Closed-loop electroosmotic microchannel cooling system for VLSI circuits. IEEE Transactions on Components and Packaging Technologies. 2002; 25(3):347-355. [4] Wei Y and Joshi YK. Stacked microchannel heat sinks for liquid cooling of microelectronic components. Journal of Electronic Packaging. 2004; 126:60-66. [5] Garimella SV, Singhal V and Liu D. on-chip thermal management with microchannel heat sinks and integrated micropumps. Proceedings of the IEEE. 2006; 94(8):1534-1548. [6] Bintoro JS, Akbarzadeh A and Mochizuki M. A closed-loop electronics cooling by implementing single phase impinging jet and mini channels heat exchanger. Applied Thermal Engineering. 2005; 25:2740-2753. [7] Simons RE. Application of thermoelectric coolers for module cooling enhancement. Electronics Cooling. 2000; 6(2):18-24. [8] Kim YJ, Joshi YK and Fedorov AG. An absorption miniature heat pump system for electronics cooling. International Journal of Refrigeration. 2008; 31(1):23-33. [9] Kandasamy R, Wang XQ and Mujumdar AS. Transient cooling of electronics using phase change material (PCM)-based heat sinks. Applied Thermal Engineering. 2008; 28:1047-1057.
Abstract for DC Poster Presentation.docxFunder Acknowledgement(s): Special thanks to Dr. Arden L. Moore, assistant professor in the Department of Mechanical Engineering and Science, LA Tech, Ruston, LA, for allowing us to compare his experimental data with our computational analysis. This work was supported by the National Science Foundation through cooperative agreement OIA-1541079 and the Louisiana Board of Regents.
Faculty Advisor: Stephen Akwaboa, stephen_akwaboa@subr.edu
Role: As a student in the CIMM REU 2017 program, I computationally modeled the finned and unfinned electronic chips as well as collected data through a computer program called ANSYS.