SENSITIVITY ANALYSIS BASED ON MORRIS SCREENING METHOD FOR BLADE DESIGN OF A CENTRIFUGAL COMPRESSOR

Resumo

Sensitivity Analysis is an important tool for works that have a several number of input
variables which can influence the final results when the goal is enhancement of any machine or
system. For centrifugal compressors, the efficiency depends on the behavior of several phenomena
such as shock waves and recirculation, which these effects are dependent of the geometry parameters
as thickness, angle and shape. In order to find the influence of the thickness and distance between
main blade and splitter on total isentropic efficiency, an Elementary Effects analysis associated to a
robust CFD model using ANSYS CFX was performed, considering a 4:1 compressor known by
NASA CC3. The results indicate that the thicknesses at medium spanwise position are more important
than those at border. Furthermore, the leading-edge parameters are also more influent than those in
trailing-edge. Finally, four variables are found as no significant effect and other five can be used for
future analysis as optimizations reducing computational cost. The work also shows that the variation
on efficiency is closely connected with the changes in most influent parameters due to its geometric
changes in specifically regions which are immersed in the source of losses cited previously.