Effects of Rust Deposition at the Axial Seal Pin Between Two Blades

Open Access
Author:
Breneman, Duane L
Graduate Program:
Mechanical Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
None
Committee Members:
  • Karen Ann Thole, Thesis Advisor
Keywords:
  • seal pin
  • leakage flow
  • secondary flow
  • rust particle deposition
  • gas turbine
  • rotating orifice
Abstract:
Rust deposits in the gap associated with the axial seal pin between two turbine blades can inhibit the vibration dampening of the pin, which can ultimately result in premature failure of components. This study investigated mechanisms leading to rust deposition in the axial seal pin between two blades. An initial particle characterization study revealed that one of the dominating effects on rust deposition is centrifugal forces. Rotation compacts rust particles significantly, doubling their bulk density when spun at engine representative forces. Static and rotating test facilities were developed to flow compressed air and particles through full-scale engine hardware and test coupons representative of the axial seal pin geometry. Rust was injected at ambient temperatures and engine-realistic pressure ratios. Reductions in flow were measured to be as high as 74%. In static tests, increasing the pressure ratio increased flow blockage for a given rust amount, whereas in rotating tests, flow blockage was independent of pressure ratio. The amount of blockage was highly sensitive to the geometry of associated area near the axial seal pin particularly under rotating conditions.