CFD evaluation of performance of Gravitational Water Vortex Turbine at different runner positions (original) (raw)
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CFD evaluation of performance of Gravitational Water Vortex Turbine at different runner position
2nd International Conference on Engineering and Technology, 2019
A free vortex is a region in which flow revolves around an axis line that requires a small head to form, about 0.7 m-2 m. In Gravitational water vortex turbine, water assuming to be non-rotational and inviscid passes through an open channel and enters the basin tangentially where it forms a powerful vortex. Then, the dynamic force of water is transmitted by the vortex to the turbine via mixed flow, impulse and reaction, phenomena. It can be a promising cheap and effective solution to compliment recent strives for renewable energy technologies. This paper deals with design and development of a prototype Gravitational water vortex turbine and analysis with computational and experimental methods. Initially, the computational method focused on determining maximum tangential velocity of water achievable in the setup without turbine. And further computational analysis was carried out for the setup with turbine to determine performance characteristics by adjusting the runner heights in three positions. Then the experimental analysis was performed with runner placed at three different heights. The experimental and numerical analysis showed best efficiency and maximum RPM (revolutions per minute), for the given prototype, when runner was at lowermost position i.e. 84 cm from top of the conical basin.
Computational and Experimental Investigation of Runner for Gravitational Water Vortex Power Plant
2017
The gravitational water vortex power plant (GWVPP) is a new type of low head turbine system in which a channel and basin structure is used to form a vortex, where the rotational energy from the water can be extracted through a runner. This study is focused on the optimization of the runner to improve the efficiency of theGWVPP. Computational fluid dynamics (CFD) analysis iscarried out on three different runner designs with straight,twisted and curved blade profiles. ANSYS CFX was used to analyze the fluid flow through the channel, basin,turbine hub and blade, and results were used to evaluatethe efficiency of each of the runner designs. The CFDanalysis showed curved blade profile to be the mostefficient profile, with a peak efficiency of 82%, comparedto 46% for the straight blade runner and 63% for thetwisted blade version. An experimental test of the turbinesystem was carried out to validate the runner analysis, in ascale version of the GWVPP. The testing showed that therunner beha...
Performance analysis of a two-stage gravitational water vortex turbine
IOP Conference Series: Earth and Environmental Science
In the present study the performance of two-stage gravitational water vortex turbine (GWVT) assembled in a conical basin with Savonius blade profile configuration has been investigated at different flow rate and vortex elevation. Two-stage GWVT with conical basin, not only increases the performance parameters with increase in flow parameters, but the lower stages also feed additional impact to the stage located above it because of forced vortex generation in the vicinity of top stage. Moreover, maximum hydraulic head drop near the orifice is the main contributor in the power generation of the bottom stage, by giving rise to strong tangential velocity. A stage starts power production as soon as the parabolic surface of the vortex approaches the corners of the blades even in the absence of a significant water-blade interaction. The developed analytical model qualitatively predicts the performance of the turbine minutely leading the experimental results quantitatively.
Effects of Geometrical Parameters in Gravitational Water Vortex Turbines with Conical Basin
Journal of Renewable Energy
Gravitational Water Vortex Power Plant (GWVPP) is an appropriate means to convert kinetic energy of water to rotational mechanical energy at the very low head site. This study aims to establish a basic reference for the design of the runner for the Gravitational Water Vortex Turbine (GWVT) with a conical basin. Seven different geometrical parameters have been identified for runner design, and the effect of these parameters on the system efficiency has been studied numerically and experimentally. The effect of these parameters has been studied over the range of speed with torque. The results from performance tests of these runners suggest that runner height is the most significant parameter to be considered in the design of a turbine runner for GWVPP with a conical basin. The results show that the efficiency of GWVT has improved up to 47.85% as obtained from experiments.
Performance analysis of multi-stage gravitational water vortex turbine
Energy Conversion and Management, 2019
In this study, the performance of a multi-stage gravitational water vortex turbine (GWVT), which is assembled in a conical basin, is investigated analytically and experimentally. Each runner of the multi-stage GWVT is independent in terms of power generation through telescopic shaft arrangement. Performance parameters, such as rotational speed, torque, power and efficiency, are analyzed under various load conditions in which the effects of design parameters, such as rotors ratio, offset distance between neighbouring runners, and intra-staging and inter-staging of two-stage and three-stage GWVT, are considered. In the multi-stage GWVT, the profile of the blades of upstream runners result in minimal vortex distortion. Thus, the power generation capacity of downstream runners are ultimately enhanced because the performance of latter runners strongly depend on the head utilization capacity of the former runner. Furthermore, the runners with blades tilted on a vertical plane are best suited for the position near the bottom of the basin, whereas cross-flow blades are recommended at the top position. Moreover, the present study suggests that the rotors ratio of the neighbouring runners be selected in such a way that the two runners have the same rotor-to-basin diameter ratio with optimum offset distance. Multistaging in GWVT demonstrates the development of a combined effect of solid body rotation and free vortex. It also shows a prominent improvement in the overall performance of the turbine compared with that of singlestage GWVT. The proposed mathematical model successfully predicts the experimental results qualitatively and quantitatively, thereby proving its reliability and robustness.
A Review of Gravitational Water Vortex Hydro Turbine Systems for Hydropower Generation
Energies
Hydropower is one of the most sustainable and desirable renewable energy sources. Gravitational water vortex hydro turbine (GWVHT) systems are one of the most suitable and sustainable renewable power generation devices for remote and rural areas, particularly in developing countries, owing to their small scales and low costs. There are various GWVHT systems with different configurations and various operating conditions. The main components of a GWVHT system include the inlet and outlet channels, a basin, and a turbine on which there are a number of blades attached. This paper presents a comprehensive review regarding the progress and development of various GWVHT systems, covering broad aspects of GWVHT systems, particularly various types of basins, inlet and outlet channels, turbines with blades which have different shapes, orientations, sizes, numbers, etc. The nature of the previous studies is summarised. The fundamentals of the vortex dynamics involved and the quantitative analys...
Runner profile optimisation of gravitational vortex water turbine
International Journal of Electrical and Computer Engineering (IJECE)
This study discusses the numerical optimisation and performance testing of the turbine runner profile for the designed gravitational water vortex turbine. The initial design of the turbine runner is optimised using a surface vorticity algorithm coded in MATLAB to obtain the optimal stagger angle. Design validation is carried out using computational fluid dynamics (CFD) Ansys CFX to determine the performance of the turbine runner with the turbulent shear stress transport model. The CFD analysis shows that by optimising the design, the water turbine efficiency increases by about 2.6%. The prototype of the vortex turbine runner is made using a 3D printing machine with resin material. It is later tested in a laboratory-scale experiment that measures the shaft power, shaft torque and turbine efficiency in correspondence with rotational speeds varying from 150 to 650 rpm. Experiment results validate that the optimised runner has an efficiency of 45.3% or about 14% greater than the initial...
IRJET- Performance Analysis of Gravitational Vortex Hydro-Turbine
IRJET, 2020
Gravitational vortex hydro-turbine works on the principle of a vortex It converts centrifugal head of vortex into shaft power. GVHT can generate electricity from renewable sources of energy. In a Gravitational vortex power plant, water enters a circular basin in tangential direction & energy is extracted from the free vortex using a turbine. The main advantages of GHVT are that it can generate electricity from the very low hydraulic head, it is environment-friendly & it is economically & socially viable. It is a new and not well-developed technology to generate electricity from low-pressure water energy sources. There is limited literature available on the design, fabrication, and physical geometry of the vortex turbine and generator. Past researches focus mainly on the optimization of turbine design, inlets, outlets, and basin geometry. However, there is still insufficient literature available for the technology to proceed beyond the prototyping stage. The turbine's theoretical energy conversion efficiency is computed to be up to 85%. The maximum efficiency obtained by the researchers is 30%, while the commercial companies claim the efficiency of the turbine around 50%. The project is based on factors such as availability of the source, desired requirement, or generation of power, a flow rate of the source and safety of the marine life in the source used. To adjust the flow rate of the inlet water from the source, a governor is mounted at the entrance of the circular basin, to ensure a desired flow rate of water, and thus, obtaining the desired capacity of power to be generated. The safety of the marine life, that may enter from the source, is ensured to slip right through the mechanisms, safely without any harm. The project aims to determine the gap in currently available technology & research progress made in recent years. The methodology includes performance analysis of GVHT, finding out the optimum shape of the basin & channel. The methods include both simulations on ANSYS fluent & manufacturing of a considerable amount of energy for the prototype based on the result obtained from the simulations for experimental analysis & testing. It also aims to study the feasibility of GVHT in a country like India.
Demand of energy is ever increasing, especially in developing countries. Renewable energy such as hydropower has become one of the most demanded sources of energy for its clean generation. Low head hydropower plant is demanded in area which cannot see grid extension due to difficult geographical terrain and other reasons. Gravitational water vortex power plant is one of such low head turbine in which the mechanical energy of free surface flowing water is converted to kinetic energy by tangentially passing the water to a basin, which forms a water vortex. This study is the analysis of different basin structures which has ability to form a gravitational vortex stream from low head, low flow water streams with the optimum runner position in the basin to maximize the output power. The analysis was first carried out by development of the model using CAD software, SolidWorks and it was simulated in commercial CFD code ANSYS Fluent for the measurement of velocity. Secondly, the result so obtained was experimentally verified by measuring the output power.
Development and Testing of Runner and Conical Basin for Gravitational Water Vortex Power Plant
The Terai region in Nepal has water resources with very low head and medium to high discharge conditions. Hence, the people of the Terai region are not being able to utilize the water resources available near them due to the limitation of technology. This study is intended to serve the purpose of further research of ultra-low head gravitational water vortex turbines useful for power generation in the Terai region. Gravitational water vortex turbine is an ultra-low head turbine which can operate in as low head as 0.7m with similar yield as conventional hydroelectric turbines characterized with positive environmental yield. This study has been carried out in two phases. In the first phase, two different turbines are to designed and fabricated and the performance characteristics of the new turbine are to be compared with that of the installed turbine. The second phase includes the design and fabrication of the conical basin. Experimental tests will be carried out and the performance of the system with the use of a conical basin will compared with that of the system using the cylindrical basin. A site testing also has been carried out to ensure the performance of system.