Work

Experimental investigation on the effect of oxidation on subcooled boiling under highly subcooled conditions

Year: 2025

Type: article

Abstract: Surface oxidation is an inherent phenomenon in boiling that fundamentally alters the heating surface through changes in chemical composition, roughness, and wettability, thereby significantly affecting heat transfer performance. This study experimentally investigates the effects of surface oxidation on both nucleate boiling and microbubble emission boiling (MEB) under highly subcooled conditions. The results indicate that while oxidation increases surface roughness and enhances wettability, thereby increasing the critical heat flux (CHF), the progressive accumulation of insulating oxide layers (Cu₂O/CuO) introduces considerable thermal resistance, ultimately decreasing the heat transfer coefficient over repeated boiling cycles. In nucleate boiling with high heat flux, the maximum bubble diameter and interval time exhibit minimal variation across multiple cycles, suggesting that heat transfer deterioration is primarily due to oxide-induced thermal resistance rather than changes in bubble dynamics. In MEB, surface oxidation reduces bubble oscillation frequency and decreases the spatial-temporal uniformity of oscillations. Acoustic measurements further show that the sound pressure level and amplitude of the high-frequency peak increase with oxidation in nucleate boiling. In MEB, oxidation shifts the dominant frequency peaks toward lower frequencies. Although surface oxidation has minimal impact on the correlation between SPL and heat flux in MEB, it significantly alters the relationship between SPL and wall superheat. This study provides insight into the effects of repeated boiling cycles on subcooled boiling, emphasizing the importance of considering surface conditions when designing and optimizing boiling heat transfer applications under highly subcooled conditions.

Source: International Journal of Heat and Mass Transfer

DOI: 10.1016/j.ijheatmasstransfer.2025.127953

Authors: Hongchi Yao, Ye Tao, Jing Luo, Hongtao Liu, Wenquan Wang, Jiguo Tang

Institutions: Sichuan University, State Key Laboratory of Hydraulics and Mountain River Engineering

Language: English

Topic: Heat Transfer and Boiling Studies

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,220

Funders: National Natural Science Foundation of China, Natural Science Foundation of Sichuan Province, Sichuan Province Science and Technology Support Program