Derivations of Correlation and Model of Transition Boiling Heat Transfer: Liquid-Solid Contact Model for Transition Boiling Heat Transfer in High Wall Superheat

The transition boiling heat transfer was examined through derivations of correlation and model. The correlation of liquid-solid contact fraction in transition boiling was derived by focusing on the dimensionless wall temperature, Θ = (T_w−T_CHF) / (T_MHF−T_CHF); the following correlation was obtained from experimental results for water, R-113 and LN₂: Γ = 1.000 − 0.9120Θ − 0.1343Θ², where q_tb = q_CHFΓ+q_MHF(1−Γ). In the present model, considering a pseudo liquid-solid contact right after detachment of a bubble from liquid-vapor interface resulted from Rayleigh-Taylor instability, transient heat conduction was analyzed in it three dimensionally. Liquid-solid contact time and area were given by the present correlation of the fractions of liquid-solid contact: τ_contact = 0.3Γ_t, A_wet = 15 × 15 Γ_a, Γ = Γ_t Γ_a = 1.000 − 0.9120Θ − 0.1343Θ², where Θ = (T_w−T_CHF)/(T_MHF−T_CHF). The prediction by the present model was in agreement with the present experimental data for water.