NUMERICAL SIMULATION ON FLOW AND HEAT TRANSFER CHARACTERISTICS IN A RECTANGULAR CHANNEL WITH KAGOME TRUSS CORES: THE INFLUENCE OF STRUT CROSS-SECTION ELLIPTICITY

The traditional Kagome trusses have circular cross-section ligaments. In this study, a Kagome truss with elliptical cross-sectional ligaments instead of circular cross-sectional ligaments is proposed. Additionally, a scheme for transforming the circular cross-sectional ligament into an elliptical ligament, which maintains the same cross-sectional area as the circular cross-sectional ligament, is proposed. Four Kagome truss structures with different cross-sectional ligaments are designed. Model-4 is a Kagome truss with traditional circular cross-sectional ligaments, whereas model-1, model-2, and model-3 are Kagome trusses of elliptical cross-sectional ligaments, with the major-to-minor axes ratio gradually decreasing from model-1 to model-3. Furthermore, the pressure drop and heat transfer performance of different models at different flow velocities are analyzed. A dimensionless number ? characterizing the overall heat transfer performance is introduced to evaluate the overall performance. The results reveal that model-1, with a major-to-minor axes ratio of 4, achieved the most minor pressure drop at all velocities, and model-2 has the best heat transfer performance at high velocities. The average overall heat transfer performances of model-1, model-2, and model-3 are 5.9%, 16.3%, and 13.3% higher than that of model-4, respectively, thereby demonstrating the significance of elliptical optimization. The best overall heat transfer performance is exhibited when the major-to-minor axes ratio of the ellipse is 2.04.