Investigation of Fluid-Induced Vibration and Heat Transfer of Helical Elastic Coiled Tube

The study of fluid-induced vibration of helical elastic coiled tubes to enhance heat transfer is very important for engineering practice and energy saving. Fluid-induced vibration and enhanced heat transfer of a helical elastic coiled tube heat exchanger were analyzed based on its finite element model, by using a two-way fluid-solid coupling method. Vibration response of the helical elastic coiled tubes, heat transfer coefficient per unit volume, and Nusselt number in vibration and nonvibration were studied at different entrance velocities and winding numbers. The results illustrate that there are a lot of vortexes in the heat exchanger and around the helical elastic coiled tubes. In the range of the entrance velocity 0.3-0.7 m /s, the vibration frequency is constant, whereas the vibration amplitude increases, and the tube vibration enhances the heat transfer of the helical elastic coiled tubes by 0.38%, 0.89%, 1.93%, and 13.65%, respectively. As the winding number increases from 5 to 9, it has a greater effect on the vibration amplitude, and the tube vibration enhances the heat transfer of the helical elastic coiled tubes by 1.93%, 3.39%, and 3.59%, respectively.