Abstract
Francis-99 is a set of workshop aiming to determine the state of the art of high head model Francis turbine simulations (flow and structure) under steady and transient operating conditions as well as to promote their development and knowledge dissemination openly. The first workshop (Trondheim, 2014) was concerned with steady state operation. The second workshop will focus on transient operations such as load variation and start-stop. In the present work, 2-D particle image velocimetry (PIV) with synchronized pressure measurements performed in the draft tube cone of the Francis-99 test case during load rejection is presented. Pressure sensors were mounted in the vaneless space and draft tube cone to estimate the instantaneous pressure fluctuations while operating the turbine from the best efficiency point (9.8°) to part load (6.7°) with the presence of a rotating vortex rope (RVR). The time-resolved velocity and pressure data are presented in this paper showing the transition in the turbine from one state to another.
Highlights
The penetration of the electricity generated from the solar and wind has raised significant concern about the grid stability [1]
In order to prepare the second workshop, 2-D particle image velocimetry (PIV) and pressure measurements were performed in the draft tube cone of the Francis-99 test case during load rejection, load acceptance, and start-stop
Unsteady synchronized pressure and velocity measurements were performed in the high head model Francis turbine during load rejection from best efficiency point (BEP) to part load (PL)
Summary
The penetration of the electricity generated from the solar and wind has raised significant concern about the grid stability [1]. Turbines have to sustain transient phenomena’s such as load variation and start-stop This leads to the unsteady pressure pulsation and development of complex flow in the runner, vaneless space, and draft tube [2,3]. In order to prepare the second workshop, 2-D particle image velocimetry (PIV) and pressure measurements were performed in the draft tube cone of the Francis-99 test case during load rejection (best efficiency point to part load ), load acceptance (best efficiency point to high load), and start-stop. These data are available on the workshop website (https://www.ntnu.edu/nvks/francis-99). The motivation behind the study is to create a good quality data base in order to understand the consequence of the transient operations and validate future transient simulations of the investigated
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
