Abstract

On crisis of transition from nucleate to film boiling

L.G. Badratinova

Dinamika Sploshnoi Sredy, No. 1, 1996, pp. 1-31.

Language russian [russian]

It is shown that the formula by Kutateladze for the critical heat flux of nucleate boiling can be obtained under the assumption that the boiling crisis occurs when the Reynolds number for vapor outflow from the wall reaches a critical value. The Reynolds number is constructed with the help of vapor outflow velocity V1 = q / ρ1 L, vapor viscosity ν1 and a characteristic thickness of a viscous sublayer in a two-phase motion existing close to the wall Δ = ρ1½ ν1 [( ρ - ρ1) g σ ] (q and L are the heat flux at the wall and the latent heat of vaporization, ρ and ρ1 - the liquid and vapor densities, g is the gravity acceleration and σ is the surface tension coefficient). The formula for Δ is obtained from a study of model problems on stability of a thin equilibrium vapor (or gas) layer located between the heated substrate (kept at a constant heat flux) and the liquid phase.