A model for droplet entrainment in heated annular flow

Studying the influence of refrigerant type on thermal efficiency of annular two-phase flows; mass transfer viewpoint

“…Regarding this assumption, entrainment rate depends on the volume of liquid removed from the wave crest, wave length, number of waves in the control volume and the wave velocity. The above statement can be simply formulated as [16]: (1) where, E, ∀ l , ρ l , N w , A co and t w are entrainment rate, liquid volume removed from each wave crest, liquid density, number of waves, interfacial area and the period of entrainment phenomenon respectively.…”

“…3(a). As demonstrated there, the surface tension force is assumed to exert just on the wave front because the wave usually flatten in the rear to experience the least possible surface tension force [16].…”

“…ρ co and u co are the homogeneous density and velocity of vapor core. Interfacial shear stress is computed in the work of Holowach and Hochreiter [16], applying liquid density and velocity instead of those of vapor core. In the present study, applying interfacial shear stress in the form of Eq.…”

“…The curvature of the wave of sinusoidal form can be calculated using the following relation [23]: K crest, avg =|−(k 2 ε)sin(kx)|/[1+((k)cos(kx)) 2 ] 3/2 (18) It is assumed for simplicity that the area on which the surface tension force acts is a semi-circle of diameter (λ/2−2x * ). This assumption is based on the wave deformation [16]. (19) The surface tension force acts tangentially to the wave profile, and since in this study the sinusoidal profile is assumed for the wave, the angle, θ shown in Fig.…”

Estimation of the radioactive aerosols capture in accidental sequences of nuclear power plants

“…Holowach [Holowach, 2002] proposes an expression for the wave amplitude that is dependent on fluid properties and interfacial shear. This methodology comes from Ishii and Grolmes [Ishii, 1975], which assumes that the motion of the wave crest with respect to the liquid film can be expressed by a shear flow model.…”