Improving the Performance and Work-Absorbing Capacity of the Axial-Flow Compressor by Using Tandem Blades

The compressor blade is responsible for increasing the flow pressure. By adding a blade behind the main blade, the compressor performance can be improved by increasing the pressure ratio and reducing the weight. The tandem improves the performance and increases the compressor absorption coefficient by increasing the pressure ratio, preventing flow separation and controlling the boundary layer. This has led compressor designers to seek the reduction in weight, and increase in the pressure ratio as well as efficiency by employing a tandem. The geometry of the compressor blade and stage along with its tandem has been obtained from previous valid sources and has been drawn in three dimensions and numerically analyzed. Then various parameters for the blade and tandem are examined separately and the pressure and velocity vectors are plotted to illustrate the control of the vortices, and the improvement of compressor performance. Finally, the characteristic curve of the compressor and the pressure ratio for this particular tandem are plotted. Calculations show that by using the tandem and removing the excess vortex after the main blade, a 28.5% increase in total pressure, a 15% decrease in relative Mach number and a 1.5% decrease in entropy is seen