Optimized design of axial flow compressors with respect to the field of operation

Following a methodology that has been recently proposed by the author, the optimization of multistage axial flow compressor design is presented by assuming as objective not only the maximum efficiency in a single operating point but also the best behaviour in an assigned range of mass flow rate or rotational speed. The optimizing technique controls a 'through-flow' model which accounts for blade losses, development of end-wall boundary layers and secondary vorticities. The optimization refers to the meridional channel geometry, blade inlet angles and deflections in fixed and moving rows of each stage. Constraints on stage loading were also established to formulate the objective function, in order to find the best compromise between the flow turning and the velocity levels for the achievement of the imposed value of total head with the maximum efficiency. The violation of such limits could also occur during the variation in operating conditions, so that the results of the optimization will depend also on the extent of the operating range.