SORPTION OF RHENIUM: RESEARCH, METHODS, AND SCIENTIFIC APPROACHES

Аннотация

In this paper, the heat transfer processes using butterfly-shaped cavities placed in the wall of a rectangular air duct were numerically analyzed. The CFD (Computational Fluid Dynamics)-based ANSYS Fluent program was used. The models were built in 3D under the condition of hot air flow, the Nusselt number, heat transfer coefficient and pressure losses were studied. The geometry of the cavity was placed perpendicular to the flow. The results were compared with a smooth-walled duct and the efficiency was evaluated. Keywords: Heat transfer, butterfly cavity, CFD, ANSYS Fluent, Nusselt number, air duct, pressure loss 1. Introduction Increasing the energy efficiency of air ducts in ventilation, air conditioning, and industrial heat exchange systems is an important task. Compared with simple smooth-surfaced ducts, deformed (e.g., grooved) surfaces increase the turbulence of the flow and enhance heat transfer. In recent years, butterfly- shaped grooves have attracted attention, as they increase heat transfer efficiency, but can also increase pressure loss. In this paper, the effect of a butterfly-shaped groove in a rectangular air duct on heat transfer processes is numerically analyzed. 2. Methodology 2.1 Geometry and dimple shape The dimensions of the rectangular air duct were taken as 200 mm × 100 mm × 800 mm. Butterfly-shaped indentations were made in the middle of the duct wall, one every 5 mm. 2.2 Creating CFD Model The 3D geometry was drawn in ANSYS Fluent using Comsol Multiphysics 6.2 and imported. The mesh structure was chosen to be denser in areas with large gradients. The final model contains over 1.2 million elements. 162 ACADEMIC RESEARCH IN MODERN SCIENCE International scientific-online conference Figure 1. a) 3D view of a butterfly shape; b) Meshed state of a rectangular air duct. 2.3 Boundary conditions - Inlet: air temperature – 60°C, velocity – 2 m/s - Outlet: atmospheric pressure (0 Pa) - On the walls: constant temperature – 30°C 2.4 Equations The main heat transfer parameters were calculated as follows: 𝒉𝑳 𝑵 = 𝒖 𝒌 𝑁𝑢 ɳ= 𝑁𝑢0 1 𝛥𝑃 ( ) 3 𝛥𝑃0 3. Results and Discussion 3.1 Nusselt Number Variation The butterfly-shaped grooves increased the heat transfer by 35–42% compared to the smooth channel. The graph below shows a comparison of the average Nusselt number for the smooth-walled channel and the butterfly- 163 ACADEMIC RESEARCH IN MODERN SCIENCE International scientific-online conference shaped grooved channel. Figure 2. Variation of Nusselt number with channel length. 4. Conclusion The results of the study showed that butterfly-shaped cavities significantly improve the heat transfer process. Compared with a smooth channel, the overall efficiency increases at the expense of a higher Nusselt number and acceptable pressure loss. This geometric approach has shown promise for application in air heating, ventilation and other heat exchange systems. Future plans: In the future, it is planned to study various combinations of cavity shape, location and size. In particular, studies will be conducted on the use of optimization algorithms (e.g. genetic algorithm) to further improve heat transfer efficiency, as well as verification of CFD results through experimental tests.