Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
OPTIMIZATION OF LASER MICROMILLING PROCESS PARAMETERS FOR TEXTURING OF NUCLEATION SITES
Submission Author:
Gabriel Serafin Couto Vieira , SC
Co-Authors:
Gabriel Serafin Couto Vieira, Milton Pereira, Marcia Mantelli
Presenter: Gabriel Serafin Couto Vieira
doi://10.26678/ABCM.COBEM2021.COB2021-2052
Abstract
Many technologies rely on the precise handling of small volumes of fluid to work, with even microscale geometric enhancements to surface capable of yielding significant results. Surface enhancements in phase change applications are examples of interaction between liquids and surfaces. As such, they can be heavily influenced by the presence or absence of appropriate-sized cavities. The use of enhanced surfaces in thermosyphons is accepted to speed up bubble nucleation. Depending on the inner conditions of thermosyphon, a delay in bubble nucleation may lead to unwanted energy accumulation and even occasional geysering of the working fluid (i.e., GBP, the Geyser Boiling Phenomenon). While laser texturing is applicable in solutions where precision is crucial, the risk of burr formation can be a deterrent. Although these burrs are also microscopic, they may negatively influence the bubble nucleation and active nucleation site viability. As such, laser texturing can become a much more viable option for heat transfer enhancement if these challenges are solved. This work aims to investigate which strategies are appropriated for nanosecond pulsed laser micromachining to create burr-free nucleation sites. First, the conditions inside a thermosyphon will be calculated on basis of experiments surrounding the investigation of the GBP. Afterward, the optimal nucleation sites for these conditions will also be calculated. Parameter combinations such as power, pulse length, and the number of pulses over the same area which lead to these optimized nucleation sites will be investigated. This work will also present options to either avoid burr formation. Lastly, a brief discussion on the viability and the possible applications will be presented.
Keywords
Laser micromachining, burr free structures, optimized parameters, nucleation sites
