Numerical Analysis of Finger Seal with Grooves on Lifting Pads

Abstract

Numerical research on lifting and sealing performance of a whole ring finger seal with grooved pad structures is presented in this paper. Different groove structures on the bottom of a lifting pad, such as one and two straight grooves, or two herringbone grooves with different gradients, etc., will be simulated. For discussing interaction between the rotor and finger seal, the vibration trajectory of the rotor is taken into account in the numerical computation. Numerical simulation results indicate that the complete ring model is more suitable than an individual finger model to simulate the fluid–solid interactions of the finger seal. Deformation of the finger seal is changed by vibration of the rotor, and it should adapt the clearance in a uniform way according to the rotor position. The grooved pad structures have effects on the leakage flows and the lifting force on the finger. Analytical data revealed that the self-adaptive performance of the finger seal to rotor vibration is subsistent. The self-adaptive performance will be helpful to make the finger seal processes lower wear and with smaller leakage in a rotor–seal system.