Author(s): J Nicolle; J-F Morissette

Linked Author(s):

Keywords: Metamodel; Hydraulic turbine; Transient stress; Modal analysis; CFD

Abstract: The present work deals with the construction of a simulation-based simplified model to provide stress of a hydraulic turbine during transient operation by leveraging two well-known concepts: hydraulic similarity and linear load combination. Because it combines multiple reduced order models, it is therefore called a metamodel. This strategy is applied to a 200 MW medium head Francis turbine which underwent an experimental campaign to acquire steady and transient stress signature. A modal analysis is first required to extract mode shapes, characteristics and corresponding stress tensors. Then a coarse CFD database is generated to populate the operating space. Modal forces are obtained through FEA for the gravitational, centrifugal and pressure loads. Modes are then combined using either quasistatic or dynamic assumptions. The model can provide in real-time most of the high amplitude stress occurring during transients and has a very good correspondence in operation.

DOI: https://doi.org/10.1088/1755-1315/1483/1/012012

Year: 2023