EFFECT OF WALL HEATING ON THE CHARACTERISTICS OF NEAR-WALL REVERSE FLOW EVENTS OCCURRING IN A TURBULENT DUCT

Direct numerical simulation is used to study the effect of wall heating on the characteristics of a near-wall reverse flow during a turbulent stream of various coolants in a duct. A temperature field is considered both in a passive scalar approximation and in a low Mach number approximation. Qualitative and quantitative results are obtained that characterize the probability of occurrence of a near-wall reverse flow in all the cases considered at a Reynolds number  \(\mathrm{Re}= 3150\)  based on mean flow velocity and duct half-height. It is revealed that, in the cases considered, the wall heating causes a two- or a threefold increase in the probability of near-wall reverse flow formation .