Numerical analysis of wave effect on steam–air condensation on a vertical surface

Highlights: • A single phase multi-species transport condensation model is applied in the simulation. • Solitary and sinusoidal waves with different types and amplitudes are selected. • Combined effects of wavy film and non-condensable gas on steam condensation are investigated. • The mechanism of the wave effect on local condensation rate under different parameters are analyzed. Steam condensation with non-condensable gas is an unavoidable problem for passive containment cooling system (PCCS) in many third generation reactors. The effects of the air mass fraction in steam–air flow and condensing wall subcooling on the steam condensation at the different gas velocities under the different types and amplitudes of solitary or sinusoidal wave walls are numerical analyzed, in the cases that the wavy film is regarded as wavy solid wall. The 41% rise of average condensation flux (ACF) of steam–air flow can be obtained in the channel with large-amplitude solitary wave wall than that of flat wall while the less variation of ACF happens in the mode with sinusoidal wave wall. The sudden expansion and contraction of flow section along the wavy wall as well as vortex generation in the channel influence local condensation flux greatly. All these results are helpful for thermal analysis of condensation in the PCCS.