EFFECT OF TUBE-TO-TUBE TIES ON FLUIDELASTIC INSTABILITY OF TUBE ARRAYS EXPOSED TO CROSS-FLOW

Tube-to-tube ties and their arrangement within the tube array are show n to affect the onset of fluidelastic instability. The influence of ti e arrangement for a single tube row and for an in-line tribe array is obtained by numerical simulation using S. S. Chen's unsteady flow theo ry. Maps of dimensionless critical velocities for groups of tubes cons isting of two, three, four, and five tubes tied to each other are deve loped for several design configurations. It is shown that the stabilit y limits can be raised by appropriate choice of tube group and tie loc ation.