Numerical study of periodical wall vibration effects on the heat transfer and fluid flow of internal turbulent flow

The applications of vibration and oscillation in heat transfer process have attracted much attention for their positive impacts on heat transfer enhancement. In this research, the flow behaviors and heat transfer in stationary and periodically cosine vibrating tubes were numerically investigated in detail. The effects of wall vibration with the amplitude ranging from 1 to 5 mm and the low frequency ranging from 1 to 10 Hz on the fluid flow resistance and heat transfer enhancement were studied for various Reynolds numbers from 5971 to 13933. The numerical results demonstrated that the heat transfer performance in the vibrating tube could be significantly enhanced by the wall vibration. The averaged Nusselt numbers with the periodical wall vibration can be as high as 2.854 times of that for static tube. However, the friction factor f of fluid flow with wall vibration is also increased by 83.3% as compared with the case for static tube. By completely evaluating j/f(1/3)-factor, all vibrating tubes exhibited better overall heat transfer efficiency than that of static tube. The j/f(1/3)-factor is increased with the increase of vibration amplitude and frequency, and the maximum enhancement ratio of 176.9% can be achieved in this study. Besides, a correlation of the heat transfer enhancement ratio for vibrating tube was also derived based on the simulation results with a maximum error of 14.77%.