In order to study the effect of alternating fluid–solid action on dynamic characteristics runner a reversible hydraulic turbine, turbine model is used as research object, and two-way coupling method iteratively calculate analyze fluid structural equations obtain under typical operating conditions. The results showed that influence high-speed water ring area certain working condition, incoming f...

Numerical investigation was performed on a semi-model (one stay vane, two guide vanes, one runner passage inclusive of main and splitter blade, the draft tube) high-head Francis turbine model with adjustable vanes in tube. The motive present study is to investigate possibility mitigate rotating vortex rope (RVR) formed at part load operating condition. Each vane tube consists hydrofoils. upper ...

important activities of die-casting die design. In normal practice, determine therunner and gating designparameters. These parameters are simulations on a computer and dry runs on adie-casting machine These iterative activities increase the manufacturing lead time and makes A system which could reduce the iterations and make the presentsa computer-aided system for runner and gating system gener...

The second part of this paper presents results of stress analysis of the whole Francis turbine runner at Derbendikan power station by using the Finite Element Method (FEM). Computations were carried out with appropriate boundary and loading conditions for water pressure obtained from CFD analysis. The analysis focuses on stress distribution in the runner blades. It has been found that the maxim...

The mechanical design of hydraulic turbines is conditioned by the dynamic response of the runner that is usually estimated by a computational model. Nevertheless, the runner has complex boundary conditions that are difficult to include in the computational model. One of these boundary conditions is the water in which the runner is submerged. The effect of the added mass and damping of water can...

In this work, the estimation of crack initiation life of a hydraulic Francis turbine runner is presented. The life prediction is based on the local strain approach to predict the initiation life. First, the analysis is carried out in air and in water condition and the runner’s natural frequencies were calculated using the finite element (FE) method. The analysis in air is compared with experime...

Metabolic Syndrome is a human condition that presents with various metabolic issues such as abnormal distribution of body fat, high blood pressure, and a prothrombotic state, among other problems (Alberti,et al, 2005). This syndrome is a risk factor for visual disorders, such as glaucoma, and is often associated with increased levels of neuroinflammation. Currently, the animal model used to rep...

Hydraulic turbines exhibit total load rejection during operation because of high fluctuations in the grid parameters. The generator reaches no-load instantly. Consequently, the turbine runner accelerates to high speed, runaway speed, in seconds. Under common conditions, stable runaway is only reached if after a load rejection, the control and protection mechanisms both fail and the guide vanes ...

Unlike many other sports, running is perceived as a sport that can be easily practiced by everybody without any need for a proper technique or previous training. Moreover, once a running pose is adapted, it becomes fairly difficult to change it for good. However, audio feedback is becoming a popular method for aiding people to improve their performance in sports. Hence, the aim of this project ...

PURPOSE The aim of this study was to examine performance, pacing strategy and perception of effort during a 5 km time trial while running with or without the presence of another athlete. METHODS Eleven nonelite male athletes participated in five 5 km time trials: two self-paced, maximal effort trials performed at the start and end of the study, and three trials performed in the presence of a ...