Design, analyses and experimental investigation of a micro hydro turbine

Mini/micro hydraulic turbines to be installed on low height and low volume flow rate rivers, are one of the solutions to the continuously increasing energy demand. In this study, a 10 kW fixed blade bulb type hydraulic turbine is designed, the design was investigation via Computational Fluid Dynamics techniques and optimized in terms of power delivered, strength analyses were performed with Finite Element Method, later on manufactured and tested in Istanbul Technical University Prof. Dr. Cahit Özgür Hydromechanics Lab.The design process has begun by using the empirical and the analytical fomulea to find out the main dimensions of the turbine, and then blade designs have been made by using the velocity triangles. The 3-dimensional designs have been validated by Computational Fluid Dynamics analyses and then the optimizations have begun. Various parameters like number of stators, suction pipe geometry, blade angles, hub diameter, tail water pipe geometry have been studied in order to increase the efficiency and the power output from the same head.One out of 15 different designs has been selected and after finite element analyses for strength calculation with a sufficient factor of safety, the mechanical design has been made for manufacturing. The sharpness of the blades have been decreased for manufaturability and rotor and stator have been machined on CNC while most of the volute has been cut from standard diameter pipes and the rest have been bent and welded.The prototype has been sent to İstanbul Technical University for hydraulic tests. It has not been possible to implement a torquemeter for moment measurement so the system efficiency has been calculated by measuring hydraulic power and generator power. Also the mass flow was too high for the test setup, so the tests have been performed at lower speeds and the results have been amended for 1500 rpm. The test results are in close agreement with numerical results.As a result of this study, a 10kW micro turbine has been designed by using numerial techniques and a desing methodology has been created. Obtaining good agreement between numerical and experimental results is important in proving the benefits of using finite analyses techniques and they are indispensible in contemporary design process.