This paper is focused on the guide vane cascade as one of most crucial stationary sub-systems hydraulic turbine, which needs to provide efficient inflow conditions runner. The vanes direct flow from spiral casing and stay towards runner, regulating desired discharge. A parametric design tool with normalized geometrical constraints was created in MATLAB, suitable for generating geometries Franci...

Abstract The present study introduces the concept of mitigating pressure pulsations in a hydro-turbine draft tube. refers to using an adjustable guide vane system adjustability relates its ability rotate around axis. test rig for experimental is high-head Francis model turbine. Three sets vanes are distributed evenly circumferentially Each consists two hydrofoils. upper hydrofoil can move lower...

Abstract We performed Large-eddy simulations of the flow in a model air Francis turbine range low-load regimes with swirler rotating at fixed frequency. All investigated revealed presence coherent helical vortex structure draft tube: precessing core. identified frequency this instability and obtained mean velocity fields to be utilized further works.

Korto’s multidimensional method for vibro-acoustical diagnostics and monitoring of turbine cavitation is based on a high number spatially distributed sensors the signal data processing that systematically utilises three dimensions: spatial, temporal, operational. The delivers unbiased intensity rich diagnostical mechanisms. It applicable Kaplan, Francis, bulb, reversible pump turbines, as well ...

CFD (Computational Fluid Dynamic) is today standard procedure for simulating and analysing fluid flow through hydraulic machines. This is a process where fluid flow domain is divided into many small volumes where governing equations are converted into algebraic equations, which can be solved numerically. Computational result strongly depends on methods used for converting governing to algebraic...

Abstract A small-scale test rig is developed to study the flow phenomena during off-design operations of a Francis turbine. The can be operated in open and closed loops for maximum head discharge 8 meters 0.055 m 3 /s. runner outlet diameter 200 mm rotates at 500 rpm. However, not model turbine as per IEC 600193. Therefore, repeatability parameters key establishing reliability measurement perfo...

Nowadays, hydropower plays an essential role in the energy market. Due to their fast response and regulation capacity, hydraulic turbines operate at off-design conditions with a high number of starts and stops. In this situation, dynamic loads and stresses over the structure are high, registering some failures over time, especially in the runner. Therefore, it is important to know the dynamic r...

In this paper, the Eulerian–Lagrangian method and Tabakoff erosion model are used to study solid–liquid two-phase flow in a Francis turbine. Through analysis of overall pattern, particle flow, concentration, wear bladeless area unit under different guide vane openings, influence runner radial gap on surrounding field characteristics openings is revealed. The results show that smaller opening va...