ABSTRACT
For efficient design and performance of condensers in traditional and modern applications a need exists for tools and techniques that facilitate attainment and accurate predictions of steady annular/stratified internal condensing flows. This chapter develops predictive tools for wavy-interface situations involving turbulent vapor/laminar condensate flows in a vertical tube. The flow is quasi-steady, that is, steady mean flow fields experience wave-induced fluctuations. The flows are sufficiently fast that the entire flow is “parabolic”, that is, conditions at any point are influenced only by conditions upstream. The chapter discusses situations where the vapor flow is slow and “elliptic.” It presents a 1-D approach for identifying good interfacial shear models for wavy-interface annular film condensation in vertical tubes. The 1-D approach provides reasonable estimates for the unknown interface location and interfacial shear which enhance the convergence of 2-D models. The chapter proposes a novel 2-D computational scheme for condensing flows specifying mean interfacial shear using “good” 1-D models.
