Methodology and Experience of Primary Design of a Transonic Axial Compressor

Abstract

The work presents the main provisions underlying the program for axial compressors calculation anddesign. The calculation of head losses and grids deflection capacity is based on the formulas of A. Komarov. Themodel contains empirical coefficients, values of which are selected during verification of the program based onthe tests results of multistage compressors and compressor stages. The main equations and algorithm for pressuresand velocities calculation under the radial equilibrium condition are presented. The use of computer programsbased on these models in the design of a 4-stage gas turbine engine compressor of moderate power with a totalpressure ratio of 3.2 and a given velocity is shown. For the first compressor stage, two variants with differentflow coefficients were compared. Variant #1 is designed with the classic recommendation to approach the samemechanical gas energy at the exit of the stage along the radius. Variant #2 is designed for a smaller flowcoefficient, but in order to ensure radial equilibrium, it was necessary to introduce a significant unevenness ofmechanical energy supply along the radius. Due to the lower kinetic energy, variant 2 has a 1.9% higher stageefficiency. Despite the fact that the loss coefficients of the blade devices are lower for variant #1. The questionremains as to how much the unavoidable mixing losses of variant #2 will reduce its efficiency in the process ofgas mechanical energy equalizing.