Linear stability of liquid films with interfacial phase change

Heat transfer — A review of 1973 literature

The fundamentals of condensation heat transfer for a pure vapor are reviewed. Calculational methods for the heat transfer coefficient and the pressure drop are presented for a wide variety of surface geometries and flow configurations, including shell-side condensation, in-tube condensation and direct-contact condensation. Enhancement techniques, including the fundamentals of dropwise condensation, are briefly described.

Fundamentals of Condensation

Laminar film wise condensation in the presence of waves with finite amplitudes on a vertical plate in gravity field has been investigated and solved by an approximate method.

Theoretical study of film wise condensation considering wave initiation

A small perturbation theory is developed for the breakdown of a thin evaporating liquid film draining down a heated tube subject to a non-negligible surface shear stress. 1The film is always so thin that entrainment is negligible. The usual traveling wave is here not adequate, and a time-independent surface perturbation which is exponential in the flow and periodic in the cross-stream direction is assumed. The appropriate Orr-Summerfeld equation and boundary conditions are then derived. Comparison with experimental data, using a large effective contact angle, obtained from the lower bound of the eigenvalue spectrum, gives good agreement for the critical Reynolds number.

Breakdown of a heated liquid initial breakdown of a heated liquid film in cocurrent two-component annular flow: i. small perturbation model

The linear stability theory is used to study stability characteristics of laminar condensate film flow down an arbitrarily inclined wall. A critical Reynolds number exists above which disturbances will be amplified. The magnitude of the critical Reynolds number is in all practical situations so small that a laminar gravity-induced condensate film can be expected to be unstable. Several stabilizing effects are acting on the film flow; at an inclined wall these effects are due to surface tension, gravity and condensation mass transfer.

E. Marschall

Papers

Stability characteristics of condensate films