Study on Unsteady Sealing Characteristics Research of High-Turbine Axial Rim Seal at Different Coolant Flow Rate
The characteristic of turbine axial rim seal will impact turbine efficiency significantly.The unsteady sealing characteristics of high-turbine axial rim seal at different coolant flow rate was investigated via accurate numerical simulation method which was verified by experiment.The numerical results show that there was increasement on sealing effectiveness accompanied with the improvement of coolant flow rates,but the sealing effectiveness increase ratio decrease significantly with coolant flow rates further increase.The"separation-fusion"phenomenon will occur in the gas intrusion area accompanied with the rotation of blade.The coolant flow rate will change the unsteady static pressure circumferential distribution of turbine hub at radial rim seal observably.The coolant flow rates will change the uniformity of flow at radial rim seal significantly.The gas intrusion vortex(GIV)and mixing induced vortex(MIV)were formed by the interaction between the gas intrusion and the sealing flow in turbine axial rim seal clearance.The radial position,size,intensity and circumferential position of GIV and MIV was affected by coolant flow rate seriously.The radial position and size of MIV Coolant flow rates affected the sealing effectiveness distribution in the axial rim seal cavity via change the radial position and size of MIV.Coolant flow rates affected circumferential nonuniformity of flow and the process of unsteady gas intrusion via change the intensity and circumferential position of GIV.
turbine axial rim sealcoolant flow ratessealing effectivenessunsteady gas intrusiongas intrusion vortexmixing induced vortex
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