STRUCTURE OF MIXED DENSITY-STRATIFIED TURBULENT-FLOW BETWEEN HORIZONTAL PARALLEL PLATES

In the turbulent boundary layer flow developed between parallel flat plates, density-stratified flow is generated by a heating wall. In such a mixed density-stratified turbulent flow, velocity and temperature were measured simultaneously. The flow structure and turbulent transport mechanism were investigated. The difference of developing processes in the stable and unstable regions resulted in the unsymmetrical profiles of velocity, temperature and turbulent quantities. From measurements of coupling probability density distribution, it was comfirmed that the thermal plume generated intermittently in the unstable region affected the turbulent structure in the stable region. The phenomenon of counter-gradient turbulent diffusion of heat was observed at the interface.