| Popis: |
In modern industrial high-output, high-efficiency engines, long turbine blades can require the use of a mid-span or partial-span damping ring for damping vibrations. However, the inclusion of a mid-span damping shroud, or “snubber,” can have negative effects on the aerodynamic performance of the gas turbine stage and engine. Therefore, a method of coupling two independent computational fluid dynamics and finite element structure software tools under an optimization environment was applied to minimize the drag force caused by the snubber, while maximizing the structural life of the blade. Following the earlier two-parameter (the shroud width and taper ratio) shroud geometry study by the authors, this study extends to the five-parameter geometry model to approach a higher performance design with controllable computational time as well. For the optimized turbine blade shroud in this case, 14.5% reduction of the maximum material stress and 22.6% decrease in the drag force from original snubber design has been accomplished. |
