2017 年 12 巻 2 号 p. JTST0017
Three-dimensional thermosolutal natural convection and entropy generation within an inclined enclosure is investigated in the current study. A numerical method based on the finite volume method and a full multigrid technique is implemented to solve the governing equations. Effects of various parameters, namely, the aspect ratio ( Az ), buoyancy ratio (N) and inclination angle (γ) on the flow patterns, heat and mass transfer rates as well as entropy generation are predicted and discussed. A comparison of 2D and 3D models at normal situation γ=0° is conducted when N varied in the transition range -2≤N≤-0.6 demonstrating that the 2D assumption can be adopted for the 3D flows when -0.5≤N≤0. The numerical outcome of the present study shows that, the thermal and solutal isosurfaces exhibit a central stratification that significantly strengthens as Az is augmented. It is also found that decreasing the aspect ratio value Az leads to weakening the total entropy generation and reducing the 3D effects exhibited within the cavity. Especial attention is attributed to analyze the periodic flow pattern that appears for Ra=104, Az =2 and γ=75°. In terms of irreversibility criterion at the oscillatory regime, total entropy generation ( Stot ) and Bejan number (Be) are seen to oscillate with the same frequency but in opposing phases and with different amplitudes.
