Abstract
The focus of this dissertation is the design of a mixed flow compressor stage with a pressure ratio of 3:1 running at 100 000 RPM with an air mass flow rate of 0,31 kg/s. The mixed flow compressor requirements were determined experimentally from a radial flow compressor on a laboratory based gas turbine engine. The radial flow compressor in the turbine engine was tested to determine the baseline requirements of the mixed flow compressor. The radial flow compressor was also numerically modelled to establish and verify the mixed flow compressor design methodology, as the mixed flow compressor falls under the family of radial flow compressors – except that the mixed flow compressor exit configuration and length differ from that of the radial flow compressor. The design methodology of the mixed flow compressor was also verified by the modeling illustrated in their mixed flow compressor design work, which covers both the design and testing. In this study, the Brayton cycle analysis was conducted using GASTURB software. The GASTURB cycle analysis used the engine parameters obtained from bench tests of the turbojet engine. This was used to generate and estimate the thrust, and the specific fuel consumption of the engine. The GASTURB software was also used to estimate the compressor performance prediction map. The type of compressor in which this requirement will be suitable was verified to be the mixed flow compressor, especially from the specific speed and diameter analysis using the bench test results. The major simulation tool or software package used for designing and predicting the impeller geometry is the NREC Concepts software package that includes COMPAL, which is the mean-line design program, AXCENT, which is the blade definition program for radial turbo machinery including three dimensional geometry generation and Pushbutton CFD, which is used to carry out three dimensional computational fluid dynamics (CFD) analysis. From this analysis and design approach, the mixed flow compressor preliminary design was obtained. In this study, the mixed flow compressor...
M.Phil.