Linearized Stability Analysis of Film Condensation

Abstract

A modified Yih analysis is used to investigate the stability of laminar film condensation on a vertical wall. The analysis presented leads to closed-form expressions for the wave amplification rate, the wave velocity, the neutral stability curve, and the critical Reynolds number. It is found that the condensation mass transfer rate has a dual role in the instability-inducing mechanism. Results indicate that surface tension, viscosity, and the overall effect of condensation mass transfer tend to stabilize while gravity tends to destabilize the flow. The critical distance predictions are an order of magnitude larger than the predictions from previous theories.