Investigation of static and rotordynamic characteristics of the segmented annular seals based on the differential quadrature method

Abstract

Theoretically, a solution model for the static and rotordynamic characteristics of a segmented annular seal based on the local differential quadrature (LDQ) method was established. The impacts of node density and the number of local support domain nodes on the accuracy of the algorithm were analyzed. A test rig for the leakage of segmented annular seals was designed and built. The leakage results measured on the test rig were compared with the theoretical analysis results to demonstrate the accuracy of the local differential quadrature method. The influence of structural and operating parameters on the seal static and rotordynamic characteristics was analyzed Based on the work carried out above. The research results indicate that when the number of local support domain nodes is equal to 3, the static and rotordynamic characteristics of the segmented annular seal can be obtained accurately based on the solution model. As the rotational speed increases, the segmented annular seal’s lift force, leakage, stiffness coefficient, and damping coefficient increase. As the pressure ratio increases, the lift force and leakage of the segmented annular seal significantly increase while the stiffness and damping coefficients decrease. As the depth and width of the pocket increase, the lift force, stiffness coefficient, and damping coefficient of the segmented annular seal first increase and then decrease. As the length of the pocket increases, the lift force, stiffness coefficient, and damping coefficient of the segmented annular seal increase. The influence of the pocket depth, width, and length on the leakage is minimal.