The program outlined continues successful earlier NSF supported research in transport process in two phase flow. The general objectives are to understand how turbulent transport of molecular species is related to Lagrangian statistics, to understand the turbulent transport of particles, droplets and bubbles that have a density different from the fluid in which they are suspended, to understand how the turbulent transport of mass at a solid/liquid or a gas/liquid boundary is related to fluid mechanical factors close to the interface, and to understand non-linear waves caused by air flow over a liquid surface. Five projects are proposed: (1) Computer studies that relate the Lagrangian and Eulerian descriptions of turbulent transport, and that provide information on the role of molecular diffusivity in diminishing turbulent transport; (2) Optical studies on the turbulent transport of drops, particles and bubbles; (3) Influence of waves on gas absorption in stratified flows; (4) Finite amplitude waves in gas-liquid stratified flows; (5) Turbulent mass transfer at a solid- liquid boundary. Important aspects of this work are that combined laboratory and supercomputer experiments will be conducted and that newly developed optical techniques will be used to study Lagrangian turbulence characteristics of particles, drops and bubbles and finally, one of the most immediate consequences to be derived from this study will be the application leading to development of improved design equations for gas/liquid flow in pipelines. The system chosen to study gas absorption is of practical importance in many process problems. However, it is also of interest to geophysicists, since the transfer across the surface of environmental waters is an important phase of the geophysical and natural biochemical cycles of numerous substances. This explains the widespread interest in it by chemists, geophysicists, civil engineers, mechanical engineers, and environmentalists.
