CFD Based Design Optimization, Fabrication and Testing of A Micro Hydro Pelton Turbine
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Date
2018-12
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Addis Ababa University
Abstract
In areas where the supply of grid power is very difficult, utilisation of Micro hydro-power as
renewable energy source is of great concern now a-days to eliminat extreme poverty around the
world. These schemes can provide environmentally sustainable electricity and mechanical power to
rural communities. For this purpose, selected types of micro hydro turbines need to be designed and
developed depending up on the site locations.
Thus, considering the potential of hydropower generation in Ethiopia, this research addresses the
design, optimization, local manufacturing, and experimental test of a model of micro hydro Pelton
turbine for one of the selected potential site (Indris River) in South West Shewa of Ethiopia to meet
the requirements of the energy demands of the nearby village as a case study.
Initially, the geometries to be compared (baseline design of the turbine) were done with the design
guide lines and tested by developing numerical model using commercial CFD. Considerations are
taken in designing the turbine with an effective post life recycling scheme in mind so that there will
be minimum wastage of resources once the turbine is made redundant.
CFD simulations using ANSYS-CFX were conducted, to optimize further the bucket shape in
order to get a cost effective runner design. Additionally, consequences of variation in each design
parameter were evaluated from the baseline design. The result of the study proposes some
modifications in the baseline design. Through the analysis, a weight reduction of around 7.6% is
achieved due to the modified runner design. Moreover, CFD was predicting a 3.9 % improvement of
hydraulic efficiency. The optimization of number of buckets, length, depth and shape of the lip curve
are the main design parameters for the achieved improvement in efficiency. It is then checked for
structural safety with a more accurate method using ANSYS. At a later stage, the model was
experimentally tested at the AAIT Lab to have a tangible confirmation of efficiency at variable
operational conditions. The experimental results confirmed a 2.8% improvement in efficiency. This
prediction was validated for the modified runner design used in the simulation using the same head
and flow rate conditions as for the baseline design.
Overall, the comparative results with CFD were satisfactory and in line with the theory, and
verifying the turbine model design effectiveness which will be useful for implementation of rural
electrification projects.
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Keywords
Rural Electrification, bucket geometry, hydro turbine, Pelton Turbine, Numerical Modeling, Computational Fluid Dynamics, optimized, Experimental Testing