Blar i Institutt for energi og prosessteknikk på tidsskrift "IOP Conference Series: Earth and Environment"
Viser treff 1-13 av 13
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A reference pelton turbine - design and efficiency measurements
(Journal article; Peer reviewed, 2014)The Pelton turbine has been subject to a varying degree of research interest since the debut of the technology over a century ago. Despite its age there are gaps in the knowledge concerning the flow mechanisms effecting ... -
An Experimental Investigation of the Hydroynamic Damping of Vibrating Hydrofoils
(Journal article; Peer reviewed, 2019)As Francis turbines are chasing a higher efficiency, while trying to accommodate a wider load region, turbine blade fatigue is becoming a more pronounced problem. Details of the Fluid-Structure Interaction (FSI) between ... -
Dynamic load on a Francis turbine runner from simulations based on measurements
(Journal article; Peer reviewed, 2014)The frequency of the Nordic power grid has become more volatile during recent years. This gives rise to two effects in synchronous machines. Firstly, as grid frequency changes the rotational speed of synchronous machines ... -
Evaluation of runner cone extension to dampen pressure pulsations in a Francis model turbine
(Journal article; Peer reviewed, 2016)Today's energy market has a high demand of flexibility due to introduction of other intermittent renewables as wind and solar. To ensure a steady power supply, hydro turbines are often forced to operate more at part load ... -
Experimental Investigation of a High Head Model Francis Turbine During Steady-State Operation at Off-Design Conditions
(Journal article; Peer reviewed, 2016)Francis-99 is a set of workshops aiming to determine the state of the art of high head Francis turbine simulations (flow and structure) under steady and transient operating conditions as well as promote their development ... -
Experimental investigation on a high head model Francis turbine during load rejection
(Journal article; Peer reviewed, 2016)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 ... -
Measurements and simulations of turbines on common grid
(Journal article; Peer reviewed, 2014)Speed droop control is of basic importance for the primary governing in the Nordic grid. The speed droop control. a mandatory and build-in regulatory loop on all larger units. is automatically changing the produced power ... -
Onboard measurements of pressure pulsations in a high head Francis model runner
(Journal article; Peer reviewed, 2019)Over the last years, there have been several incidents with cracks in high head Francis turbines. These cracks are understood to be related to pressure pulsations, vibration modulus and the combination of these. In this ... -
Pressure Pulsations and Fatigue Loads in High Head Francis Turbines
(Journal article; Peer reviewed, 2019)The Norwegian power system today includes a relatively large percentage of Francis turbines with a head of above 300m, in the world. This leads to a need to maintain and develop the national competence regarding the ... -
Signature analysis of characteristic frequencies in a Francis turbine
(Journal article; Peer reviewed, 2019)The present work investigates the unsteady pressure fluctuations in a model Francis turbine that are observed during steady state operation. Focus of the present study is to correlate pressure fluctuations between stationary ... -
The numerical and experimental investigation of erosion induced leakage flow through guide vanes of Francis turbine
(Journal article; Peer reviewed, 2019)In Guide Vanes (GV) of Francis turbines, a portion of the pressure head of water converts into velocity head. This causes high acceleration of the flow in GV before reaching the runner. Furthermore, GVs are accompanied ... -
Variable-speed operation and pressure pulsations in a Francis turbine and a pump-turbine
(Journal article; Peer reviewed, 2019)The paper presents result from model measurements of the efficiency and pressure pulsation intensities for two low-specific-speed hydraulic turbines operated at variable speed, namely, one splitter-bladed Francis turbine ... -
Velocity and pressure measurements in guide vane clearance gap of a low specific speed Francis turbine
(Journal article; Peer reviewed, 2016)In Francis turbine, a small clearance gap between the guide vanes and the cover plates is usually required to pivot guide vanes as a part of governing system. Deflection of cover plates and erosion of mating surfaces causes ...