PIV measurements of waves and turbulence in stratified horizontal two-phase pipe flow

摘要: Abstract Stratified two-phase pipe flow of air and water is studied in a horizontal transparent 50 mm inner diameter with the goal obtaining detailed velocity measurements wave characteristics flowing liquid layer. The field below moving interface was measured by combining planar PIV profile capturing technique. Depending on rates water, layer can be laminar, transitional or turbulent, smooth wavy. Conditional averaging based phase applied order to decompose into three components: time-averaged velocity, wave-induced fluctuations turbulence-induced fluctuations. Detailed statistics phase-averaged fields were obtained for laminar turbulent wavy cases. waves are shown asymmetric, gravitational capillary forces similar magnitude. linear theory provides good approximation profiles. In region close interface, however, nonlinearity caused deviation. cases, deviation also observed wall, due existence an oscillatory boundary separation motion only partly successful wide range wavelengths heights occurring all