Dynamic stability analysis of a cylindrical shell subjected to swirling annular flow under thermal loads

• The viscous effect of fluid destabilizes the annular flow-shell system.
• The rotation of fluid lowers the critical axial flow speed.
• A combined action of the fluid forces and thermal loads degrades the stability of shells.

Considering thermal loads, a dynamic stability analysis is presented for a flexible cylindrical shell conveying a viscous, incompressible, swirling fluid in the annulus between the inner shell and the outer shell in this paper. The inviscid fluid-dynamic forces associated with shell motions are treated in the frame of the potential flow theory. And the steady viscous forces are derived by using fully developed turbulent theory. The thermal loads are determined by the thermo-elastic theory. Shell motions are described by Flügge's thin shell equations, which are modified to incorporate the prestresses relating to the steady viscous forces. The theoretical analysis is conducted by the zero-level contour method and the Galerkin's method. This study shows that, for annular flow, the effect of viscosity renders the system more unstable. Fluid rotation strongly degrades the stability of the shell. The influences of a combined action of the viscous annular flow having two velocity components and the thermal loads on the stability of shells are discussed in detail. Also, the critical temperature rise is found.