Parametric study on the effect of inlet and outlet pipe shape on the flow fluctuation characteristics associated with a positive displacement hydraulic turbine. (January 2021)

• Record Type: Journal Article
• Authors: Sonawat, Arihant; Choi, Young-Seok; Kim, Kyung Min; Kim, Jin-Hyuk
• Is Part Of: Renewable energy. Volume 163(2021)
• Page Start: 1046
• Page End: 1062
• Publication Date: 2021-01
• Subjects: Renewable energy (RE) -- Positive displacement turbine (PDT) -- Flow pulsations -- Computational fluid dynamics (CFD); Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.renene.2020.09.025
• Languages: English
• ISSNs: 0960-1481

Abstract

Abstract: For applications involving very low specific speeds resulting from very low flow rates with medium to high heads, a special class of hydraulic turbine known as Positive displacement turbine (PDT) is most suited. These turbines are not very common, but they can effectively harness the micro and Pico hydropower. For the present work, the effect of inlet and outlet pipe's cross-sectional shape on the fluid flow pulsations and overall performance of the developed PDT has been analyzed using Computational Fluid Dynamics (CFD) approach. Initially, the cross-sectional shape of the pipe used for transporting the working fluid to and from the turbine rotors was circular. Subsequently, the influence of square and rectangular cross-sectional shaped pipe designs was analyzed. Also, parametric studies were performed to find the dimensions of rectangular and variable cross-sectional shaped pipes. It was observed that the initial flow pulsations greatly reduced for specified variable cross-sectional pipe compared to the other shapes. Also, an increment of 0.824% in hydraulic efficiency was observed compared to the initial circular pipe. At the rated conditions, the PDT with twisted rotors having fully circular shaped pipe developed 7.15 kW of output power with a hydraulic efficiency of 66.2% from the experimental study. Highlights: Effect of stator's cross-sectional shape on the flow pulsations & performance. Parametric studies to find the dimensions of variable cross-sectional shaped stator. Causes for reduced pulsations and improved efficiency with the stator shape. Validation of adopted CFD strategy with the in-house experimental test.