Microscales of saturated pool film boiling

• Published in: International journal of heat and mass transfer 2003-09, Vol.46 (20), p.3809-3814
• Main Authors: Arpacı, Vedat S., Lee, Hyo Seok
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Heat capacities of liquids; Liquid-vapor transitions; Physics; Specific phase transitions; Thermal properties of condensed matter; Thermal properties of liquids: heat capacity, thermal expansion
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/S0017-9310(03)00198-4

Two thermal Kolmogorov scales for pool film boiling η θ B ∼ να 2 2 B 1/4, η θ C ∼ α 2 3 B 1/4, are introduced. Here ν, k and ρ respectively denote the vapor kinematic viscosity, thermal conductivity and density, α 2= k/ ρc p2 and c p2 = h fg /Δ T (a two-phase thermal diffusivity and specific heat) suggested for notational convenience, and B the rate of buoyant production of turbulent vapor energy. In terms of these scales, the pool film boiling heat transfer is shown to be ℓ η θ B ∼Nu∼Ra 2 1/3, ℓ η θ C ∼Nu∼ Ra 2Pr 2 1/3, where ℓ is an integral scale, Ra 2 and Pr 2 are the Rayleigh and Prandtl numbers based on α 2. The microscale foundation of the earlier correlations of the turbulent pool film boiling data of all fluids except for liquid metals is demonstrated in terms of η θ B. An original correlation in terms of η θ C Nu=0.17(Ra 2Pr 2) 1/3, is proposed for turbulent pool film boiling data of liquid metals.