2001 Volume 44 Issue 4 Pages 712-720
Experimental validation of the design criteria for preventing the failure of a thermometer well by vortex-induced vibration is presented, clarifying the effects of Reynolds number and structure damping. An existing avoidance criterion for the vortex-induced vibration in the flow direction, which is given in terms of the reduced velocity Vr as Vr<1.0, has been developed based on the experimental data mainly in the sub-critical range. The applicability of this criterion in the super-critical range is examined in this paper based on the results of experiments performed in the Reynolds number region from 7.8×104 up to 1.1×106 at Vr=1.0. On the other hand, an existing suppression criterion of vortex-induced vibration in the flow direction is given in terms of the reduced damping Cn as Cn>1.2 (or 2.5) under the condition of Vr<3.3 in design guidelines. This criterion, however, has been proposed based on very limited available data The appropriateness of the suppression criterion is also examined in this paper based on the results of experiments in realistic thermometer well conditions, i.e. cantilever cylinders with varied structure damping in a pipe water flow. As a result, it becomes clear that Vr<1.0 is applicable in the super-critical range up to 1.1×106 and that the criteria of Vr<3.3 and Cn>1.2 are reasonably applicable to a cantilever cylinder in a pipe water flow.