Axial Stiffness Analysis of Twisted Tubes

In this study, finite element analysis was performed to calculate the axial stiffness of twisted tubes. Experiments were carried out to verify the calculation. Effects of the twist ratio, lead and thickness on the axial stiffness are investigated. It is found that with increasing the twist ratio or decreasing the lead, the axial stiffness of the twisted tube is decreased. A so-called stiffness reduction coefficient for the twisted tubes is given based on the numerical results. With the stiffness reduction coefficient, the twisted tube heat exchangers could be more accurately designed.