NumericalInvestigation on the Effect of Number of Blades on the Performance of a Turbocharger Compressor

In the present work, the effect of number of blades of a turbocharger is investigated numerically. First, the geometry of impeller and volute of Garrett T25 turbo compressor is acquired using 3D scanning. Then the acquired geometry is modeled in Ansys software. The flow is acquired for a compressor with default number of blades (6 blades) first, and the number of blades is changed to 5 blades. This study is also done for 4 and 7 blades. The effective area is increased when the number of blades is decreased, so the compressor is chocked later. As a result, mass flow can increase in a compressor with fewer blades. On the other hand, slip factor and transferred power to fluid are augmented when the number of blades is increased, while the power and pressure ration is decreased when the number of blades is more than 6 blades. The acquired results show that the optimum performance of the compressor is obtained in a compressor with default number of blades in a wide range of mass flow rate.