Mišrios konvekcijos skaitiniai tyrimai vertikaliame plok#x0161;čiame kanale pereinamojo tekėjimo zonoje esant vienkryptėms tėkmėms 1. Tėkmės struktūros analizė.

Results of the numerical modelling of mixed convection in a vertical flat channel in case of a transitional region for aiding flows are presented. Unsteady numerical two-dimentional simulations were performed using the FLUENT 6.1 code. Investigations were performed in airflow of 0.2 MPa absolute pressure for Reynolds number 2016 and Grashof number 3.9x108 (in quasisteady state). Numerical results revealed three characteristic zones of the flow along the channel. In the first zone, the parabolic velocity profile was transformed into an M-shaped profile. This was a stable zone. For the flow parameter indicated above it existed up to x/de = 8. The region of x/de = 8 -- 10 was a region of the reversal flow in the core of the channel (zone with recirculation). Next to that zone we had a zone with an unstable vortex flow. In this zone, a typical wall temperature and Nusseldt number pulsations were noted. The results of heat transfer modeling were compared with the experimental data and showed a good agreement (difference between numerical and experimental data was no more than 4%) in the region of the stable laminar flow and a sufficient agreement (with the difference no more than 12%) in the recirculation zone. [ABSTRACT FROM AUTHOR]