Experimental study and modelling of nucleate boiling heat transfer intensification through surface texturing

• Grant number: 22/06392-7
• Support Opportunities: Generation Project Research Grant
• Duration: May 01, 2023 - April 30, 2028
• Field of knowledge: Engineering - Mechanical Engineering - Thermal Engineering
• Principal Investigator: Debora Carneiro Moreira
• Grantee: Debora Carneiro Moreira
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated researchers: Armando Ítalo Sette Antonialli ; Carlos Eiji Hirata Ventura ; Satish Gopalrao Kandlikar
• Associated scholarship(s): 24/05488-6 - NUCLEATE BOILING OVER FLAT SMOOTH SURFACES: INFLUENCE OF OPERATIONAL PARAMETERS AND SUBSTRATE MATERIAL, BP.IC; 23/12381-0 - Investigation of bubble dynamics in nucleate boiling, BP.MS; 23/05683-0 - Experimental study and modelling of nucleate boiling heat transfer intensification through surface texturing, BP.GR

Abstract

Phase-change processes are of great relevance in numerous industrial and technological applications, particularly some energy systems are intimately related to processes like boiling, condensation and frost formation, due to their high heat transfer capability. Thus, phase change heat transfer has been largely investigated in the context of thermal management solutions, successfully reducing energy consumption of data center, despite the steep rise in their workload, highlighting the strategic character of boiling heat transfer for the reduction of green-house gas emissions and to contain the Global Warming. In spite of numerous efforts in understanding and enhancing boiling heat transfer, most works in heat transfer augmentation are essentially empirical and lack of deep discussion, while the comprehension of the interaction between wall properties and boiling phenomena remains a challenging task, requiring further investigation. In this context, the present research proposal aims to theoretically and experimentally investigate fundamental aspects of nucleate boiling, studying the dynamics of bubbles nucleating in single and multiple artificial nucleation sites and assessing the interactions between multiple bubbles through optical visualization using a high-speed camera. The correlation between the heat transfer behavior and the high-speed images of the boiling process, will enable the modelling of nucleate boiling phenomena and the proposition of textured optimized surfaces for boiling heat transfer. The modified surfaces will be fabricated through machining processes, and besides boiling heat transfer characteristics the test sections will be characterized for their static and dynamic contact angles, roughness, morphology and geometry, using a contact angle analyzer and a confocal microscope before and after boiling runs. Further investigation on the boiling mechanisms will be carried out with multiple optical techniques. Four master students enrolled in the Graduate Program in Mechanical Engineering from UFSCar will work in this project, and part of their theses will be developed in the Thermal Analysis, Microfluidics and Fuel Cells Laboratory at RIT, under the supervision of Dr. Satish Kandlikar. (AU)