Abstract:
The report opens with a brief survey of various blade profiles and their two-dimensional cascade performance characteristics. The requirements of the different stages of an axial compressor are then discussed. This is followed by the design details of a suitable test compressor embodying in each stage the blade profile most suited to the duty that stage has to perform. The test results for this compressor are given and discussed at some length. It is concluded that a compressor with suitable blade profiles in each stage has considerable advantages over one in which the same profile is used throughout. These advantages are : (a) The compressor will have a good surge line. (b) Its part-load efficiency will be high. (c) It will have a wide characteristic at constant speed. (d) It may have a high efficiency at high flow. (e) It will have a higher peak efficiency than some designs. (f) It should be more reliable. A possible disadvantage is that it may have a lower surge pressure ratio at the design speed than a compressor with high load blade sections throughout.
