Discussion: “Fluid Dynamic Excitation of Centrifugal Compressor Rotor Vibrations” (Thompson, W. E., 1978, ASME J. Fluids Eng., 100, pp. 73–78)

Abstract

The author has mentioned two very important points in this paper viz. (a) Calculation of impeller passage flow by streamline curvature technique and (b) use of Damping Factor to obtain converged results. These two numerical problems give enormous amount of grief to the users as he has rightly pointed out. The author has overcome these problems by 1) using smoothed spline fit for curvature calculations and 2) uncoupling the estimated new location of streamlines from the continuity considerations. Unfortunately the details of these are not available in the paper and since the computer programme evolved is proprietary to Turbo Research Inc. this useful information will not aid researchers in the field. The writer's experience with regard to the streamline curvature techniques and spline fits is highlighted in the following paragraphs. Four programs based on 1) Novak [29] 2) Oldham [30] and 'By W. E. Thompson published in the March 1978 issue of the ASME