A Study Of Turbulent Penetrative Thermal Convection Using Stereoscopic Particle Image Velocimetry PDF Download

Present dissertation describes the turbulent convection in horizontal layers of air and water separated by an evaporative shear-free water surface during natural convection. A detailed analysis of the hydrodynamic turbulent structure on water and air sides is presented in this study. The major portion of the research comprised of experimental investigation in addition to simulation of simultaneous airside and waterside velocity fields. The experimental measurements were made using non-intrusive state-of-the-art techniques, namely particle image velocimetry (PIV) and laser induced fluorescence (LIF) for instantaneous measurements of velocity and temperature fields, respectively. The numerical study shows organized bulk vortical motions on air and water sides. The results also show that for unstable thermal stratification the magnitude of the airside velocities is an order of magnitude higher than the waterside velocities. The experimental results show that the water and air flow fields undergo three-dimensional flow interactions which form complex flow patterns. A detailed spectral analysis has been performed to investigate the temporal and spatial scales of turbulent motions induced during natural convection. The wavenumber and frequency spectra showed the existence of two distinct power law regimes. In low wavenumber (100 rad/m