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 ...

Nowadays, the challenge in hydraulic turbine design is the multi-objective design of turbine runner to reach higher efficiency. The hydraulic performance of a turbine is strictly depends on runner blades shape. The present paper focuses on the application of the multi-objective optimization algorithm to the design of a small Francis turbine runner. The optimization exercise focuses on the effic...

Use of the appropriate propagule size can maximize propagation rate strawberry (Fragaria × ananassa) transplants in an autotrophic transplant production method, a novel method plant factory with artificial lighting for production. During 90 days after planting initial propagules, cumulative number produced from propagules 5 mm crown diameter (CD5) was greater than those 4 (CD4) or 6 (CD6). Time...

Pelton turbine is the most commonly used high head impulse turbine with low discharge. For obtaining highest power output from runner one of the most important parameter is quality of jet which strikes bucket tangentially. The quality of jet and its impact work depends on the distance between the nozzle exit and runner along with its angle of strike. In the present paper, the effect of distance...

We derive a hybrid feedback control law for the lateral leg spring (LLS) model so that the center of mass of a legged runner follows a curved path in horizontal plane. The control law enables the runner to change the placement and the elasticity of its legs to move in a desired direction. Stable motion along a curved path is achieved using curvature, bearing and relative distance between the ru...

The causes of resonance of a certain model pump-turbine unit during startup process were investigated in this article. A three-dimensional full flow path analysis model which contains spiral case, stay vanes, guide vanes, runner, gaps outside the runner crown and band, and draft tube was constructed. The transient hydraulic excitation force of full flow path was analyzed under five conditions n...