A shell and tube heat exchanger is analyzed numerically to determine the effect of the baffle angle on the heat transfer coefficient and the pressure drop. Heat exchangers that use shells and tubes benefit greatly from baffles because they allow for more effective heat transfer with less pressure drops. CATIA and ANSYS—Workbench Flow Simulation software is used to construct heat exchangers with baffle angles of 0, 10, 20, 30 and 40°, and fluid dynamic simulations are also performed. The greatest heat transfer occurred at a baffle angle of 40°, assuming a constant heat transfer coefficient between the baffle and shell. It has been shown that a 40° baffle angle produces the least amount of pressure drop. Our heat exchanger features a combination of rotational and helical baffle patterns, which greatly improves its heat transfer coefficient per unit pressure drop. © 2023 Elsevier B.V., All rights reserved.