A Contribution to the Study of the Design of an Industrial Centrifugal Compressor

Abstract

The present work has had as a starting point an already existing high hub/tip ratio industrial centrifugal compressor design. An effort was undertaken to design a first new machine using theoretical methods, keeping, however, the overall geometrical dimensions, issued from the experience of the industry. The new design was manufactured and tested. The test results were found to be rather good, compared with the current industrial experience. Additionally, a second new design was undertaken which had as aim to diminish the axial part length, leaving untouched the hub/tip ratio. If this effort was successful, it would mean that the length of the shaft for a multistage arrangement could be diminished and, thus the need for such a high hub/tip ratio, resulting from the shaft diameter. It was found, actually, possible to reduced the axial length of the inducer by a factor of two, approximately. The second new design was manufactured and the resulting machine, when tested, was found to have the same performances as the first new design. A rather interesting point of the whole design procedure was the fact that a boundary layer calculation method was used in the blade-to-blade surface, which could take into account the influence of the Coriolis force and blade curvature on turbulence. The impact of this influence on the whole design was found to be decisive. The calculation procedure, the two designs and the overall test rests are described in the present work.