Theory versus experiment for the rotordynamic characteristics of a smooth annular gas seal at eccentric positions Academic Article uri icon


  • The paper discusses experimental results for the rotordynamic coefficients of a smooth gas seal of eccentricity ratios out to 0.5. These results fall under these factors; 1) effects of speed, 2) inlet pressure, 3) pressure ratio, 4) fluid prerotation and 5) eccentricity. Experimental results are compared to predictions for static and dynamic characteristics based on an analysis by Yang. In general, the theoretical results reasonably predict the experimental results. However, theory over predicts direct stiffness, fails to indicate the decrease in Kxx, and incorrectly predicts the direction of change in Kxx. In addition, direct damping is substantially underpredicted for low preswirl values and low supply pressures, but the predictions improve as either of these parameters increase.

author list (cited authors)

  • Alexander, C. R., Childs, D. W., & Yang, Z.

publication date

  • December 1994