On the Hydrothermal Behavior of Fluid Flow and Heat Transfer in a Helical Double-Tube Heat Exchanger with Curved Swirl Generator; Impacts of Length and Position

The hydrothermal behavior in a helical double-tube heat exchanger is numerically estimated. A new type of swirl generator with two sections, including; outer curved blades and semi-conical section holes the inner section, employed. Two geometrical factors, containing length (L1) position (S), are used for investigation. calculations were performed by commercial FVM code, ANSYS FLUENT 18.2. numerical outcomes show that shorter leads to better behavior. Accordingly, model L1 = 100 mm at m˙ 0.008 kg/s achieves maximum thermal performance about 17.65, 53.85, 100% enhancement compared models 200, 300 mm, without generator. Among different studied positions generator, transfer coefficient average Nusselt number entire mass flow rates belong case S 0.3π mm. Moreover, higher than cases 0.1π 0.5π 11.11, 53.84, 100%, respectively.