The Boiling Phenomena and their Proper Identification and Discrimination Methodology.

Area of Science:

• Thermodynamics and Heat Transfer
• Fluid Mechanics
• Phase Change Phenomena

Background:

• The traditional Nukiyama pool-boiling curve (heat flux versus temperature difference) is insufficient for accurately identifying boiling phenomena.
• Heating and cooling phases can mimic boiling behavior, leading to misidentification of actual boiling processes.
• A lack of established methods for discriminating between various boiling methodologies exists in open literature.

Purpose of the Study:

• To develop a reliable condition for identifying the existence of boiling behavior during heating or quenching.
• To establish a protocol for accurately discriminating between different boiling regimes.
• To address the limitations of existing methods for boiling phenomena analysis.

Main Methods:

• Development of a new condition, represented as (1/St), to describe the existence of boiling.
• Validation of the developed condition using diverse boiling processes.
• Establishment of a protocol based on the slope of the heat transfer coefficient versus temperature difference (h versus ΔT) curve, rather than the traditional boiling curve.

Main Results:

• The developed condition (1/St) has been successfully validated across various boiling processes.
• The proposed protocol, utilizing the slope of the h versus ΔT curve, effectively identifies proper boiling regimes.
• The new methodology provides a more accurate discrimination of boiling behavior compared to the Nukiyama curve.

Conclusions:

• The traditional Nukiyama curve is not a definitive indicator of boiling phenomena.
• The newly developed condition and protocol offer a robust method for identifying and discriminating boiling regimes.
• This research provides a valuable tool for accurate analysis of phase change processes in various applications.