NUMERICAL SIMULATION OF EROSION IN FRANCIS TURBINE

Abstract

Numerical simulation is used to analyse complex flow of fluid in Francis turbine by using computational code. Numerical simulation is done at best efficiency point (BEP) to predict erosion rate, erosion region and comparison between erosion rate predicted by (Desale et al.,2011) erosion model and Tabakoff erosion model because analysis of sediment erosion of Francis turbine gives an indication of wear intensity and about most vulnerable zone on turbine components. (Desale et al., 2011)erosion model has more parameters than Tabakoff model which are affecting the erosion rate. Numerical study of erosion is done by varying concentration of sediments keeping other parameters such as particle size, impingement angle, hardness, shape factor are constant. The whole numerical analysis is done in Ansys CFX. In CFX, (Desale et al.,2011) erosion model is not inbuilt so it is required a computer code in FORTRAN language.To validate numerical simulation two monitor points DT5 and DT6 are given in fluid domain whose pressure data are calculate at every time step by solver and these pressure profile pattern are matched with pressure profile given at NTNU for similar monitor points.