Dominant flow features of twin jets and plumes in crossflow

A brief survey of the recent studies of “twin jets in crossflow” (TJICF) by the present authors is carried out. A particular emphasis is put on the new velocity-field analysis based on kinematic decomposition techniques. In addition, some new results dealing with mixing and dispersion of twin buoyant plumes from different stack arrangements are also presented. The configuration of the TJICF consists of a pair of identical jet nozzles and jet-flow conditions at the nozzle exits and the jets are issuing normally into a crossflow/crosswind. The paper deals predominantly with the nozzle arrangements placed flush with the ground plane. The flow phenomenon represents just the problem of interaction and mixing between two adjacent non-buoyant jets or buoyant plumes governed by large-scale vortical structures and background turbulence. Similarities and differences between the dominant mean-flow vortical features, vorticity and circulation associated with three basic nozzle arrangements (tandem, side-by-side and oblique arrangements) are examined, and the comparison with the single jet case is also carried out. Some dispersion aspects reflected in the concentration measurements of twin buoyant stack plumes are also discussed.