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A flow over hot water film in horizontal channel (Poiseuille–Benard flow) is studied experimentally and by means of CFD. Averaged temperature and concentration fields were measured in central transverse plane using RTD and capacitive humidity probe for different Ri = Gr/Re2. A similarity of thermal and concentration field is discussed and the influence of thermal and humidity field by radiative heat transfer is investigated since it has a considerable effect. Same cases are modeled by CFD in commercial code Star-CCM+. Simulated thermal and concentration fields shows similar character as those from measurements when radiative heat transfer mode is considered.

An experimental study was conducted to investigate the thermal field of low-speed flow of moistair in a horizontal rectangular duct, uniformly heated from below (Poiseuille–Benard flow). Averaged temperature fields were measured in vertical mid-plane using thermocouples. The buoyancy-induced secondary flow is interacting with forced Poiseuille flow which leads to complex flow behaviour with flow reversal along the top surface. Two types of bottom boundary conditions were examined: aluminium plate (only heat transfer) and water film (simultaneous heat and mass transfer) heated to the same temperature. Presence of mass transfer causes stronger transient behaviour above the bottom surface and enhancing of heat transfer, but the overall character of the thermal field remains the same as in case of heat transfer only.

The article deals with the analysis of CFD results of the turbulent synthetic jet. The numerical simulation of Large Eddy Simulation (LES) using commercial solver ANSYS CFX has been performed. The unsteady flow field is studied from the point of view of identification of the moving vortex ring, which has been identified both on the snapshots of flow field using swirling-strength criterion and using the Dynamic Mode Decomposition (DMD) of five periods. It is shown that travelling vortex ring vanishes due to interaction with vortex structures in the synthesised turbulent jet. DMD modes with multiple of the basic frequency of synthetic jet, which are connected with travelling vortex structure, have largest DMD amplitudes.