Author(s): Pawan Lal Bijukchhe; Hari Prasad Neopane; Amul Ghimire; Atmaram Kayastha; Ole Gunnar Dahlhaug; Sailesh Chitrakar

Linked Author(s): Ole Gunnar Dahlhaug

Keywords: Francis turbine; Sediment erosion; OpenFOAM

Abstract: Sediment erosion is a serious problem in the Himalayan region and has caused a huge economic loss in hydropower plants. Moreover, hydropower plants suffer from irregular flow availability forcing them to operate at off-design conditions, which further aggravates the erosion. In hydraulic turbines, erosion has been found to be localized and is prominent in places with high velocity or acceleration or vortex formation. The effect of erosion is seen to be severe while operating the turbine in the off-design condition which is directly dependent on the flow irregularities in those operating conditions. The complication arises with the complication to maintain a synchronous rotational speed while operating a turbine. A method for minimizing the erosion effect is optimizing the blade profile. In this study, the sediment resistivity of an optimized blade is compared with the reference blade of the Jhimruk Hydropower Plant, using numerical methods. OpenFOAM was used to perform the numerical study of particle-laden flow at different operating conditions. The volume of material eroded was calculated using the built-in function particleErosion with Finne erosion model. The erosion resistivity was found to be better in optimized blade at all operating conditions. The erosion on the suction side of the blade was significantly reduced while on the pressure side, the impact was seen to be increased.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p0833-cd

Year: 2023