Comparative evaluation of the thermal performance of a new sustainable energy system implemented with flat plates

This study focuses on enhancing the efficiency of heat exchangers by introducing new rib configurations periodically mounted on the inner walls of a channel. The objective is to optimize heat transfer while minimizing pressure losses simultaneously. Three rib shapes: trapezoidal, pentagonal, and triangular were studied, each installed at regular intervals with the same height. To further improve thermal performance, an optimization approach based on varying rib height was proposed, resulting in three innovative configurations. In the first configuration (Case 1), rib height increases linearly along the main flow direction; in the second (Case 2), it decreases linearly; and in the third (Case 3), it first decreases and then increases. Numerical simulations were conducted using the Navier-Stokes equations to model turbulent flow and heat transfer in a rectangular duct. The impact of several parameters, such as Reynolds number (5,000 ≤ Re ≤ 18,000), relative rib height (1 ≤ e ≤ 1.8), and rib arrangement, was analyzed. The results show that triangular ribs, particularly in the optimized configurations, provide superior thermal performance with an acceptable trade-off in pressure drop.