Numerical study of camber and stagger angle effects on the aerodynamic performance of tandem-blade cascades

Abstract

Jet engine manufacturers and designers are seeking for lighter and smaller type of axial compressors. Improving the aerodynamic characteristics of blades is carried out by controlling the boundary layer. One way to control the boundary layer is using tandem blades. Tandem-blade cascades are capable of using highly loaded stages for axial compressors because they provide more works than single-blade cascades. In other words, tandem blades help to achieve a specified total pressure ratio with less number of stages. Therefore, one of the most important problems for researchers is to optimize the aerodynamic parameters of tandem blades. Changing the geometrical parameters of blades is a method to achieve this purpose.In this work, the stagger and camber angle of each blade are first changed while the other geometrical parameters such as overall camber, total stagger angle, the axial overlap, percent pitch and chord ratio are fixed. Secondly, the overall camber angle of tandem blade is changed by increasing the difference between the stagger angle of the first and second blade while the type of two airfoils, axial overlap and percent pitch, overall chord length and overall stagger angle are fixed.The aerodynamic performances of the generated tandem-blade cascades are obtained using two-dimensional numerical solution of flow. For this, a viscous turbulent flow solver is used for solving the Navier-Stokes equations. In these simulations, inlet Mach number is fixed to 0.6.