Design Optimization of Axial Hydraulic Turbine for Very Low Head Application

Studies are conducted on axial hydraulic turbine for very low head application which operates on low speed. Design optimization is generated by optimizing the blade airfoil and blade cascade during development of the turbine blades. Blade airfoil is optimized to obtain optimum value of ratio of Lift coefficient Cl and Drag coefficient Cd, in the range of turbine operation by utilizing of XFOIL that controlled via MATLAB. These airfoils are used to develop the blade cascade. To increase the benefits of fluid flow passing through the turbine blades, the analysis and optimization of the blade cascade is conducted. Vortex panel method is used to analyze the fluid flow inside cascade to gain the maximum of the lift force, in order to optimize the potential power of the fluid that can be utilized by the turbine rotor. The cascade optimization is including arrangement of the incidence angle of the cascade to reduce cascade losses and blade loading by applying the concept of shock-free inflow. Numerical analyses are conducted to determine the performance of the designed turbine with the commercial CFD. The results of numerical simulations show that the turbine can be operated at a maximum efficiency of 91% at various ranges of flow rates.