Interfacial characteristics of steam jet condensation in crossflow of water in a vertical pipe

An experimental study is performed to investigate the interfacial characteristics of steam jet condensation in crossflow of water in a vertical pipe. A high-speed camera is applied to capture the raw images of the condensing jet in the flow visualization test section. According to both the gray and gray-gradient profiles of the original images, an interfacial identification method is proposed to reveal the interfacial characteristics, including the jet plume shape, jet centerline trajectory and jet penetration length. Based on the expansion features of the two phase interface, the condensation regimes are classified into five categories, including double expansion-contraction, expansion-contraction, cylinder, contraction and hemisphere shapes. The steam mass flux, scaled by critical steam mass flux at ambient pressure, is found to be irrelevant to the transitional lines among the hemisphere, conical and expansion-contraction shapes in the condensation regime map. The jet momentum ratio as a dominant factor is introduced to correlate the jet centerline trajectory, and the predicted results are within ±20% of the experimental data. The dimensionless jet penetration length decreases with increase of ambient pressure, and is found to be in the range of 0.58–6.49 in present experiments. A correlation for prediction of the dimensionless jet penetration length is established, and the discrepancies between the predicted results and experiments are within ±15%.