TY - JOUR

T1 - Bubble characteristics on surface boiling: experiments and implementation of numerical models

AU - Levin, A. A.

AU - Khan, P. V.

AU - Safarov, A. S.

AU - Chernov, A. A.

N1 - This work was supported by a grant from the Russian Science Foundation (project No. 22-19-00092-П).

PY - 2026/7

Y1 - 2026/7

N2 - Boiling heat transfer under highly unsteady thermal conditions is critical for many advanced energy systems, yet the predictive capability of existing models remains limited due to a lack of experimental data under rapid heating. This work presents new experimental data on nucleate boiling of subcooled water at surface temperature rise rates from 500 to 20,000 K/s, initial liquid temperatures from 30 to 110 °C, mass flow rate 0.1 kg/s, and an absolute pressure of 0.29 MPa. A total of 97,091 high-speed video frames were processed, yielding 917,198 individual bubbles with their characteristics. The RPI model of near-wall heat transfer was used for numerical simulation of unsteady heat transfer at nucleate boiling. The results demonstrate that while the incipience of boiling under dynamic conditions can be described by classical steady-state correlations, the subsequent bubble dynamics are governed by the transient thermal state of the superheated layer and correlate strongly with the Fo number, necessitating dynamic models for accurate prediction of heat transfer. The study conclusively demonstrates that the missing element in current models is the dynamic evolution of the superheated layer thickness, which must be determined numerically.

AB - Boiling heat transfer under highly unsteady thermal conditions is critical for many advanced energy systems, yet the predictive capability of existing models remains limited due to a lack of experimental data under rapid heating. This work presents new experimental data on nucleate boiling of subcooled water at surface temperature rise rates from 500 to 20,000 K/s, initial liquid temperatures from 30 to 110 °C, mass flow rate 0.1 kg/s, and an absolute pressure of 0.29 MPa. A total of 97,091 high-speed video frames were processed, yielding 917,198 individual bubbles with their characteristics. The RPI model of near-wall heat transfer was used for numerical simulation of unsteady heat transfer at nucleate boiling. The results demonstrate that while the incipience of boiling under dynamic conditions can be described by classical steady-state correlations, the subsequent bubble dynamics are governed by the transient thermal state of the superheated layer and correlate strongly with the Fo number, necessitating dynamic models for accurate prediction of heat transfer. The study conclusively demonstrates that the missing element in current models is the dynamic evolution of the superheated layer thickness, which must be determined numerically.

KW - Nucleate boiling

KW - Numerical computation

KW - Thermal physics experiments

KW - Transient heat transfer

UR - https://www.scopus.com/pages/publications/105040506578

UR - https://www.mendeley.com/catalogue/6949eb5d-23a0-3f18-b566-6b568d40c67b/

U2 - 10.1016/j.applthermaleng.2026.131610

DO - 10.1016/j.applthermaleng.2026.131610

M3 - Article

VL - 301

JO - Applied Thermal Engineering

JF - Applied Thermal Engineering

SN - 1359-4311

M1 - 131610

ER -