DIRECT NUMERICAL SIMULATION OF AIR HEATED CYLINDER WAKE IN TRANSITIONAL STATE. PART I: CYLINDER HEATING EFFECT ON STRONG TURBULENCE ANISOTROPY (STA), AND DETERMINATION OF STA SUPPRESSION

摘要

A variation of strong turbulence anisotropy (STA) with cylinder heating, and, as a result, STA suppression, are here first elucidated in the air heated wake in the transitional state at Reynolds number Re = 300 and Richardson number Ri = 0.3. Simultaneously, new facts for variations of velocities u, v, and w, i.e., the upward, horizontal, and spanwise directions, and wake motion by cylinder heating are first elucidated. Here STA is defined such that, in velocities u, v, and w, laminar velocities arise in at least one directions but turbulence arises in the remainder of directions.