Investigation of flow and temperature patterns in direct contact condensation using PIV, PLIF and CFD

In this study, experiments have been performed for the steam injected centrally at the bottom of a vertical rectangular water vessel. Instantaneous velocity and temperature field near the plume as well as in the downstream have been measured in a vertical plane through the central axis. For this purpose, Particle Image Velocimetry (PIV) and Planar Laser Induced Fluorescence (PLIF) have been employed. The velocity profile of the region above the condensation region was found to be self-similar with a small downward velocity near the wall due to recirculation. The instantaneous (20-ns integration time) thermal images obtained from PLIF had a spatial resolution of 100 μm with a field of view of 100×100 mm. The time averaged velocity and temperature profiles are computed from an ensemble of 100 velocity/temperature images. The present work is also concerned with CFD simulation by employing k-ε and large eddy simulation (LES) turbulence models. All the measurements and simulations were carried out by varying nozzle upstream pressure in the range of 0.3–0.35 MPa (corresponding nozzle velocities were in the range of 286–304 m/s) with the nozzle diameter of 1 mm.