# A Novel Design and Performance Optimization Methodology for Hydraulic Cross-Flow Turbines using Successive Numerical Simulations

## TL;DR

This paper presents a new systematic methodology for designing and optimizing hydraulic Cross-Flow turbines using successive numerical simulations, improving efficiency and adaptability across various operating conditions.

## Contribution

It introduces a simplified, step-by-step design process and demonstrates how single simulation results can be generalized to a class of turbines.

## Key findings

- Achieved peak hydraulic efficiency of 91% in simulations
- Maintained high efficiency across wide flow and head variations
- Streamlined design process reduces development time

## Abstract

This paper introduces a new methodology for designing and optimizing the performance of hydraulic Cross-Flow turbines for a wide range of operating conditions. The methodology is based on a one-step approach for the system-level design phase and a three-step, successive numerical analysis approach for the detail design phase. Compared to current design methodologies, not only does this approach break down the process into well-defined steps and simplify it, but it also has the advantage that once numerical simulations are conducted for a single turbine, most of the results can be used for an entire class of Cross-Flow turbines. In this paper, after a discussion of the research background, we explain the design process used and the ANSYS-based CFD model of the turbine in detail. The design process consists of three steps. First, designing nozzle geometry; second, optimizing runner parameters; and third, enhancing turbine performance by analyzing various load conditions. A turbine designed using this process in a simulation case study achieves a peak hydraulic efficiency of 91% and peak overall 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.