Effect of curvature diameter on secondary flow generation for square channel spiral coil sub-cooled condenser

This paper oriented towards spiral coil sub-cooled condenser (SCSCC) which is used for the automotive air conditioning system. Therefore, the effect of curvature diameter has been carefully measured by CFD as it reduces/intensify the centrifugal force. This centrifugal force is responsible for Dean vortices and leads to the generation of secondary flow inside the refrigerant. By taking advantage of this secondary flow, the performance of the SCSCC can be improved. CFD analysis comprises curvature diameter from 13mm to 110mm, which varied the Dean number from 7577 to 2605. The author tried to evaluate the complicated phenomena that occurred within the SCSCC. However, the turbulent kinetic energy which is one of the critical factors of heat transfer coefficient illustrates 0.009m²/s² and 0.006m²/s² for large and small Dean number, respectively, toward the outer side of the channel. Under the present CFD condition, the secondary flow velocity was largest when using the curvature diameter of 18 mm, which was the medium condition.