Derivation of cavitation characteristics of a 3MW prototype Francis turbine through numerical hydrodynamic analysis. (2020)

• Record Type: Journal Article
• Authors: Tiwari, Gyanendra; Kumar, Jitendra; Prasad, Vishnu; Patel, Vivek Kumar
• Is Part Of: Materials today. Volume 26:Part 2(2020)
• Page Start: 1439
• Page End: 1448
• Publication Date: 2020
• Subjects: Cavitation -- Francis turbine -- CFD -- Cavitation model -- Suction head -- Erosive wear; Materials science -- Congresses -- Periodicals; 620.1
• DOI: 10.1016/j.matpr.2020.02.297
• Languages: English
• ISSNs: 2214-7853

Abstract

Abstract: Cavitation is one of the major causes for erosive wear in reaction hydraulic turbines. Evaluation of cavitation characteristics is one of the most important tasks while designing a water turbine. Aim of present work is to analyze the effects of cavitation phenomenon at different operating regimes of a 3 MW capacity prototype Francis turbine using CFD code ANSYS CFX. Detailed flow field analyses for part loads of 60% and 80%, full load and overload operation of 120% with and without cavitation are performed. A comparative study among different turbulent models is also carried out in order to select the most suitable and compatible model with cavitation model based on Rayleigh-Plesset equation. Different stages of profile cavitation in runner and development of cavitation in draft tube for different operating conditions are analyzed thoroughly. Estimation of suction head (turbine setting above the tail race) and turbine cavitation coefficient is one of the major objectives of the work. A critical study of variation of different flow parameters for with and without cavitation cases is one of the important highlights of the paper. Computationally obtained results are compared with experimental and literature results which are found in well accord with the former.