Performance of a Radial-inlet Impeller Designed on the Basis of Two-dimensional-flow Theory for an Infinite Number of Blades PDF Download

Author: I. A. Johnsen
Publisher:
ISBN:
Category : Compressors
Languages : en
Pages : 19

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Book Description
A radial-inlet impeller based on two-dimensional-flow theory has been investigated in a research program to establish correlation between flow theory and impeller performance. The simplifying assumptions of an infinite number of blades and an incompressible fluid were made for this impeller design. The blade shape was determined by imposing a predetermined vortex distribution that was chosen to relieve the loading in the critical regions of the impeller passage. The performance of the impeller was experimentally obtained in a variable-component test unit in conjunction with a vaneless diffuser of NACA design. An analysis of flow characteristics in the compressor, using static-pressure experimental data and the assumption of an infinite number of blades, indicated that the peak impeller efficiency was high and that the low over-all efficiency could be largely attributed to losses in the vaneless diffuser. The entrance section of the impeller and the passage in the region of the impeller-blade tip operated ineffectively even at the point of peak over-all efficiency. The entrance loss, whcih became very large at high flow, was the principal factor determining the form of the compressor-performance curve. The method developed for determining compressor performance from static-pressure measurements is limited to radial-inlet-type impellers in which flow is essentially two dimensional.