Jung, In Hyuk Kim, Young Soo Shin, Dong Ho Chung, Jin Taek Shin, Youhwan 2024-01-19T20:02:40Z 2024-01-19T20:02:40Z 2021-09-02 2019-05-15 0360-5442 https://pubs.kist.re.kr/handle/201004/119994 The quality of the jet injected from a nozzle is one of the key factors that affects the performance of Pelton turbines. In this study, for the first time, experiments and numerical simulation were conducted to investigate the effect of the spear needle eccentricity on the jet flow in micro Pelton turbines. Results show that the eccentricity of the spear needle causes jet diffusion under low flow conditions and significantly increases the loss of the spear nozzle (injector). Furthermore, the increase in the eccentricity ratio causes extreme jet separation and jet diffusion, and the loss of the spear nozzle increases by 52% (from 453 W to 688 W) when the eccentricity ratio increases by 6%. Analysis of the results confirmed that the pressure deviation and jet velocity imbalance caused by eccentricity are the primary causes of jet diffusion. Furthermore, the results confirm that the eccentricity of the spear needle in the case of a low-capacity Pelton turbine has a significant effect on the jet quality. Thus, further studies on the eccentricity are required to improve the performance of the Pelton turbine. Published by Elsevier Ltd. English PERGAMON-ELSEVIER SCIENCE LTD ENERGY RECOVERY OPTIMIZATION DESIGN Influence of spear needle eccentricity on jet quality in micro Pelton turbine for power generation Article 10.1016/j.energy.2019.03.077 1 ENERGY, v.175, pp.58 - 65 ENERGY 175 58 65 scie scopus 000466999400006 2-s2.0-85063292960 Thermodynamics Energy & Fuels Thermodynamics Energy & Fuels Article ENERGY RECOVERY OPTIMIZATION DESIGN Pelton turbine Pressure-retarded osmosis Spear nozzle Eccentricity Flow visualization Numerical simulation