In this study, the effect of tangential blade lean on the aerodynamic characteristics of low-transonic, high-aspect-ratio axial flow compressor rotor has been investigated by using the computational fluid dynamics. The B-Spline curvature with four control points of 25%, 50%, 75% and 100% of span have been used to define the blade stacking line. Various leaned rotors have been created by rotating the circumferential position of control points and they have been simulated by Computational Fluid Dynamics (CFD). At the best state, the leaned blade improves the adiabatic efficiency and total pressure ratio of compressor about 0.55% and 0.75%, respectively. The results show that, lean angle at 100% span has most effect in the peak adiabatic efficiency rather than lean angle at other control points. Also, the results indicate that, in low-transonic, high-aspect-ratio rotor blades, the tangential change of the stacking line only causes the reduction of secondary flow, while the previous studies on high-transonic low-aspect-ratio rotor blades, such as NASA Rotor 37 and NASA Rotor 67 revealed the movement of shock wave toward the downstream and the reduction of the secondary flow. Manuscript profile

In this research for reducing the effect of losses and increasing the efficiency, the bowing in the rotor and stator blades is used. In one mode rotor blades are curved and in other one, stator blades are curved. The amount of rotor loss, due to changes in the thickness of the trailing edge and operating rotational speed, have been investigated. To confirm the accuracy of the results, a turbine stage whose experimental results are available is modeled and numerical results have been compared with experimental results that indicate acceptable compliance. The turbulence model k-w-SST is used to solve turbulent flow. The positive bowing, creates a pressure gradient from the two ends of the blade towards the center of the blade, which leads to the directing of the secondary flows toward the center of the blade. This reduces the losses in the two ends of the blade and increases the loss in the middle part of the blade. Increasing the thickness of the trailing edge, as well as increasing the turbine’s operating rotational speed, will increase the loss. The curved rotor increases the efficiency and mass flow and power by 0.4% and 0.5% and 0.8% respectively and the curved nozzle reduces the efficiency and power by 0.3% and 4.9% but increases the mass flow by 0.2%. It also increases the thickness of the trailing edge of the first rotor from 0.2mm to 0.9mm at 24000 rotational speed and increases the total loss by about 35%. Manuscript profile