Design and Numerical Analysis of Hydrocoil Turbine with Constant and Variable Blade’s Pitch

In recent years, because of need to energy production at low cost, using micro hydro turbines has been very attractive. The low construction costs, easy installation and maintenance, low head and flow requirements, small size, no need for the extensive power network and decentralization of hydro power are some of the unique characteristics of Micro hydro turbines. Hydrocoil turbine as a new, efficient and affordable axial flow turbine is one of the best options for distributed generation of electricity. Although Hydrocoil’s design is mainly inspired by Archimedes screw turbine, there are differences in their blade’s pitch and installing angle. In this work, two different samples of hydrocoil turbine with constant and variable pitches have been studied numerically under identical conditions to study the effect of pitch changes on operating point at constant head and five different rotational speeds. The results indicate that efficiency and power of variable pitch turbine are 30 to 40 percent more than constant pitch turbine. These results provide necessary background to build optimized variable pitch hydrocoil for the first time in Iran.