Ongoing experiments at Turbine Testing Lab

A series of experiments is being carried out at Turbine Testing Lab for investigating the correlation between several parameters affecting sediment erosion.

Recently, one of the major objectives of the project, i.e. to design Francis turbine runner for variable speed operation was completed. The research was carried out by Mr. Saroj Gautam, who is involved as a researcher in this project. Optimization of the runner has been performed in two folds: i) Minimizing sediment erosion considering basic design parameters termed as Optimization I and ii) Improving overall performance of the turbine parameterizing the geometrical configuration of the runner termed as Optimization II. In Optimization I, a multi-objective design procedure to develop a Francis turbine runner for maximizing the efficiency, as well as minimizing the sediment erosion is discussed.

The design methodology is parameterized in a MATLAB algorithm. Parameterized runner designs are implemented in the Design of Experiment (DoE) to get sample runners. These sample runners are investigated using a commercial CFD tool to obtain efficiency and sediment erosion data. Thus, Multi-Objective Genetic Algorithm (MOGA) is implemented to generate an optimized runner blade.

Implementation of the procedure discussed in the Optimization I can be a crucial step for designing the turbines that are vulnerable to sediment erosion. In Optimization II, the idea of implementing the design of a high head Francis turbine into the optimization is presented. Generated reference runner from basic design is subjected to optimization considering the necessary design parameters as an input, output targets and the constraints. Response Surface Model (RSM) is used to predict the output parameters by changing the input parameters using second order polynomial function.

The generated sample runners are used in the optimization based on Multi-Objective Generic Algorithm (MOGA) to generate final optimal runner.

Result of optimization of Francis runner blade

The research team of FranSed-project is currently involved in validating the new design using Rotating Disc Apparatus. A separate set of experiments is being conducted for developing an erosion model, which is suitable for complex geometries involving fillets, radius of curvatures and steps.

Cooperation with Nepal Electricity Authority for prototype turbine testing

On September 14, 2020, an MoU was signed between Nepal Electricity Authority (NEA), Generation Directorate and Kathmandu University, School of Engineering, for ‘Condition Monitoring of Hydropower plants in Nepal owned by NEA (CMHydro)’.

The total project budget of around 16 million NPR (for 3 years) is aimed to identify the general and specific problems in hydropower plants in Nepal along with carrying out investigation, determination and finalization of the possible parameters for condition monitoring.

The project is aimed for contributing the prototype testing objective of FranSed-project by having a close co-ordination with NEA. In this new project, six hydropower plants of Nepal owned by NEA will be primarily considered for study, out of which, four of them have Francis turbines (Kaligandaki A HPP, Devighat HPP, Panauti HPP and Seti/Fewa HPP).

Connection between different projects currently being held at KU: