Document Type : Original Article
Professor and head, Mechanical Power Engineering Dept, Zagazig University.
Research engineer, Egypt Air co.
A computer package is developed to furnish a preliminary design for the multistage axial flow compressors normally found in aero-engines and industrial gas turbines. The inputs to this code is the requested pressure ratio, mass flow rate, rotational speed, isentropic efficiency as well as the inlet total pressure and temperature. The outputs of this package are the number of stages, annulus dimensions at inlet and outlet, and two dimensional mean flow characteristics. Such 2-d results are next used . to obtain the 3-d variation from hub-to-tip sections of the blades using different methods. Such analyses provide the velocity triangles over different sections of the blades at the inlet and outlet to successive stages. Consequently, a layout of the whole compressor as well as the degree of blade twists over its height for both stator and rotor blade rows are calculated. To assure the structural integrity of the compressor blades, mechanical design is also employed for calculating both centrifugal tensile and gas bending stresses. Moreover, the initially assumed efficiency is recalculated using available cascade data.