Influence of selected parameters on micro gas turbine compressor design

The design a micro gas turbine engine is a process that requires analysis of a number of parameters. The initial stage requires consideration of more than 40 parameters [3]. The whole analysis can be made with analytical tools. However, these kinds of tools are limited to preliminary designs. After 1D-calculations and the establishment of the first CAD model, it is recommended to identify the sensitivity of the design. With a modern numerical environment such as ANSYS CFX, it is possible to predict a trend that gives the designer a 3D feedback about the initial design behaviour. For presented centrifugal compressor case, the selected parameters are vaneless diffuser space, design angle and number of stator blades. For qualitative evaluation – important results that influence design are mass flow rate, total pressure and isentropic efficiency. These results are important to turbojet engine performance and efficiency. All chosen parameters respond to given criteria. Validation and verification is still required due numerical errors that are included in CFD modelling. The advantage of 3D prediction is the possibility to eliminate gross errors before parts are sent into production.