Use of Successive Numerical Simulations to Design and Optimize the Performance of High-Efficiency Hydraulic Cross-Flow Turbines

This paper introduces a new process for designing and optimizing the performance of high-efficiency hydraulic Cross-Flow turbines for a wide range of operating conditions. The process uses a simple method for the system-level design phase and a three-step, successive numerical simulation approach for the detail design phase. Compared to current design methods, this method not only breaks down the process into well defined steps, thereby simplifying it, it has the advantage that once the numerical simulations are concluded for a single Cross-Flow turbine, most of the results can be used for an entire class of Cross-Flow turbines. In this paper, after discussing the research background, we explain the process used and the ANSYS-based turbine CFD model in detail. The process consists of three steps. First, designing the nozzle geometry; second, optimizing rotor parameters; and third, enhancing the performance of the turbine under various load conditions. The turbine designed by this process achieves a peak efficiency of 82% that is maintained for volume flow rates as low as 14% of the nominal value and water head variations up to 30% of the nominal value.