At low flow rate operation, Francis turbines feature a cavitating vortex rope in the draft tube resulting from the swirling flow of the runner outlet. The unsteady pressure field related to the precession of the vortex rope induces plane wave propagating in the entire hydraulic system. The frequency of the vortex rope precession being comprised between 0.2 and 0.4 times the turbine rotational s...

Cooling Water Pump berfungsi sebagai penyuplai air untuk sistem pendinginan di PLTA Asahan 1 yang mendinginkan minyak dan udara. Sistem pendingin udara terdapat pada Generator Air Cooler, system Thrust Bearing Oil Turbine Guide Upper Lower Cooler. bersumber dari draft tube (pipa pembuangan) dipompakan oleh Pump. digunakan setelah akan disalurkan kembali melalui pemipaan menuju

The paper focuses on the influence of reshaped elbow geometry draft tube unsteady pressure field under different operating conditions. experimental investigations are conducted considering two simplified geometrical configurations tubes with sharp heel and modified/reshaped elbow, respectively. discriminated power spectra (rotating plunging components) acquired signals wall determined five leve...

In the present study, a reduced model of Francis-99 turbine was investigated numerically at part load operating condition. The consists standalone draft tube domain turbine. Numerical studies performed in past on nearly complete hydro-turbine models (inclusive spiral casing, distributor domains, runner, and tube) reportedly consist large number computational grids. This may increase costs data ...

Varying the generator load of a hydro turbine results in short-term changes rotation frequency runner, leading inevitably to flow instability and strong swirling behind turbine. This may lead formation unsteady regimes featured by vortex known as precessing core (PVC) Dorfler et al. (2012). effect causes dangerous periodic pressure pulsations that propagate throughout water column draft tube. T...

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 ...

The importance of renewable energy sources for the electrical power supply has grown rapidly in the past decades. Their often unpredictable nature however poses a threat to the stability of the existing electric grid. Hydroelectric powerplants play an important role in regulating the integration of renewable energy sources into the network by supplying on-demand load balancing as well as primar...

Abstract Automatic optimization is becoming increasingly important in turbomachinery design to improve the performance of machine components and Evolutionary Algorithms (EAs) play a very role this task. The main drawback EAs large number evaluations that are required obtain an “optimal” result. Consequently, order keep computational time affordable frame for purposes, either mesh size has be li...