scholarly journals Radial Thrust of Low-Head Cross-Flow Water Turbine.

1995 ◽  
Vol 61 (588) ◽  
pp. 3012-3017
Author(s):  
Takaya Kitahora ◽  
Junichi Kurokawa ◽  
Tomitarou Toyokura
Keyword(s):  
Cross Flow ◽  
Water Turbine ◽  
Low Head ◽  
Radial Thrust

Study on the Flow Field of an Undershot Cross-Flow Water Turbine

2014 ◽  
Vol 620 ◽  
pp. 285-291 ◽  
Author(s):  
Yan Rong Li ◽  
Yasuyuki Nishi ◽  
Terumi Inagaki ◽  
Kentarou Hatano
Keyword(s):  
Free Surface ◽  
Flow Field ◽  
Water Depth ◽  
Open Channel ◽  
Rotation Speed ◽  
Cross Flow ◽  
Water Turbine ◽  
Low Head ◽  
New Type ◽  
Type Water

The purpose of this investigation is to research and develop a new type water turbine, which is appropriate for low-head open channel, in order to effectively utilize the unexploited hydropower energy of small river or agricultural waterway. The application of placing cross-flow runner into open channel as an undershot water turbine has been under consideration. As a result, a significant simplification was realized by removing the casings. However, flow field in the undershot cross-flow water turbine are complex movements with free surface. This means that the water depth around the runner changes with the variation in the rotation speed, and the flow field itself is complex and changing with time. Thus it is necessary to make clear the flow field around the water turbine with free surface, in order to improve the performance of this type turbine. In this research, the performance of the developed water turbine was determined and the flow field was visualized using particle image velocimetry (PIV) technique. The experimental results show that, the water depth between the outer and inner circumferences of the runner decreases as the rotation speed increases. In addition, the fixed-point velocities with different angles at the inlet and outlet regions of the first and second stages were extracted.

scholarly journals Study on an Undershot Cross-Flow Water Turbine with Straight Blades

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Yasuyuki Nishi ◽  
Terumi Inagaki ◽  
Yanrong Li ◽  
Kentaro Hatano
Keyword(s):  
Flow Field ◽  
Output Power ◽  
Cross Flow ◽  
Open Channels ◽  
Small Scale ◽  
Hydroelectric Power ◽  
Turbine Efficiency ◽  
Water Turbine ◽  
Low Head ◽  
Hydroelectric Power Generation

Small-scale hydroelectric power generation has recently attracted considerable attention. The authors previously proposed an undershot cross-flow water turbine with a very low head suitable for application to open channels. The water turbine was of a cross-flow type and could be used in open channels with the undershot method, remarkably simplifying its design by eliminating guide vanes and the casing. The water turbine was fitted with curved blades (such as the runners of a typical cross-flow water turbine) installed in tube channels. However, there was ambiguity as to how the blades’ shape influenced the turbine’s performance and flow field. To resolve this issue, the present study applies straight blades to an undershot cross-flow water turbine and examines the performance and flow field via experiments and numerical analyses. Results reveal that the output power and the turbine efficiency of the Straight Blades runner were greater than those of the Curved Blades runner regardless of the rotational speed. Compared with the Curved Blades runner, the output power and the turbine efficiency of the Straight Blades runner were improved by about 31.7% and about 67.1%, respectively.

AERODYNAMIC MODELS APPROXIMATE FOR ESTIMATING THE BLADE PERFORMANCE OF A DARRIEUS-TYPE CROSS-FLOW WATER TURBINE

2020 ◽  
Vol 47 (1) ◽  
pp. 85-98
Author(s):  
Fatima Meddane ◽  
Tayeb Yahiaoui ◽  
Omar Imine ◽  
Lahouari Adjlout
Keyword(s):  
Cross Flow ◽  
Water Turbine

Improvement of Torque Performance of a Vertical Axis Type Marine Turbine for a Water Current Generation System

2010 ◽  
Author(s):  
Tomoki Ikoma ◽  
Shintaro Fujio ◽  
Koichi Masuda ◽  
Chang-Kyu Rheem ◽  
Hisaaki Maeda
Keyword(s):  
Turbine Blades ◽  
Angle Of Attack ◽  
Cross Flow ◽  
Vertical Axis ◽  
Hydrodynamic Forces ◽  
Water Current ◽  
Current Channel ◽  
Marine Current ◽  
Water Turbine ◽  
Type Water

This paper describes the possibility of an improvement of torque performance and hydrodynamic forces on a vertical axis type water turbine, used for marine current generating system. The water turbine analyzed here is based on a Darrieus turbine with vertical blades. We considered possibilities of controlling the angle of attack of blades in order to improve the starting performance and to reduce energy loss during the rotation of the turbine. We used blade-element/ momentum theory in order to investigate the variations appearing in torque performance when the angle of attack were controlled. We also proved the validity of our predictions of hydrodynamic forces on the blade and the turbine, made through CFD calculation, by comparing them with the results of corresponding model tests in a current channel. In the corresponding model test we investigated not only the hydrodynamic forces on the turbine with three fixed blades, but also the inline force and the cross-flow force on the rotating turbine with three blades. Regarding the cyclic pitching of turbine blades, results suggest that significant increase in average turbine torque is possible.

Investigating barotrauma in juvenile salmon passing through a very low head turbine using response surface methodology

2021 ◽  
pp. 095440622110504
Author(s):  
Mehrshad Foroughan ◽  
Alireza Riasi ◽  
Amir Bahreini
Keyword(s):  
Chinook Salmon ◽  
Cfd Simulation ◽  
Geometrical Parameters ◽  
Innovative Design ◽  
Computational Costs ◽  
Water Turbine ◽  
Low Head ◽  
Computational Fluid Dynamics Cfd ◽  
Biological Performance ◽  
Riverine Fish

Although hydropower is a clean source of energy, in some cases, it can jeopardize the life of some species of riverine fish. Very Low Head (VLH) water turbine is an innovative design that aims at reducing the adverse effects of such hydroelectric facilities. In this research, two methodologies are integrated to investigate barotrauma in juvenile salmons passing through this particular turbine. First, to quantify barotrauma, we implement a method known as BioPA (Biological Performance Assessment) by combining the results of some laboratory experiments on juvenile Chinook salmon moving through a simulated turbine passage with the Computational Fluid Dynamics (CFD) simulation of the flow field in this environment. In the second part, we added surrogate-based modeling as a tool, which enabled us to study the effects of two geometrical parameters on the environmental performance of the VLH turbine with low computational costs. The results indicate a significant dependency between the installation angle of the VLH turbine and the severity of the barotrauma of this particular fish. In addition, further investigations suggest that the region near the middle of blades is the safest for fish in the case of decompression.

The Helical Turbine and Its Applications for Hydropower Without Dams

2002 ◽  
Author(s):  
Alexander M. Gorlov
Keyword(s):  
Cross Flow ◽  
Environmentally Friendly ◽  
Open Ocean ◽  
Water Currents ◽  
Low Head ◽  
Tidal Streams

The objective of this paper is to introduce an environmentally friendly Helical Turbine that has been developed to operate in free or ultra low-head water currents without dams. The turbine is a cross flow unidirectional rotation machine that makes it particularly valuable for ocean applications, such as reversible tidal streams in ocean bays, estuaries and canals, streams in open ocean, underwater currents generated by wave fluctuations etc.

3D RANS Modeling of a Cross Flow Water Turbine

2013 ◽  
pp. 405-418 ◽  
Author(s):  
Christian Pellone ◽  
Thierry Maitre ◽  
Ervin Amet
Keyword(s):  
Cross Flow ◽  
Water Turbine ◽  
Rans Modeling

scholarly journals A Study on Developing Pico Propeller Turbine for Low Head Micro Hydropower Plants in Nepal

2014 ◽  
Vol 9 (1) ◽  
pp. 36-53 ◽  
Author(s):  
Pradhumna Adhikari ◽  
Umesh Budhathoki ◽  
Shiva Raj Timilsina ◽  
Saurav Manandhar ◽  
Tri Ratna Bajracharya
Keyword(s):  
Cross Flow ◽  
Design Flow ◽  
Constant Thickness ◽  
Manufacturing Cost ◽  
Scaling Effects ◽  
Speed Increase ◽  
Hilly Region ◽  
Low Head ◽  
High Head ◽  
Airfoil Blades

Most of the turbines used in Nepal are medium or high head turbines. These types of turbines are efficient but limited for rivers and streams in the mountain and hilly region which have considerably high head. Low head turbines should be used in the plain region if energy is to be extracted from the water sources there. This helps in the rural electrification and decentralized units in community, reducing the cost of construction of national grid and also to its dependency, in already aggravated crisis situation. There are good turbine designs for medium to high heads but traditional designs for heads under about 5m (i.e. cross flow turbine and waterwheel) are slow running, requiring substantial speed increase to drive an AC generator. Propeller turbines have a higher running speed but the airfoil blades are normally too complicated for micro hydro installations. Therefore, the open volute propeller turbine with constant thickness blades was ventured as possible solution. Such type of propeller turbine is designed to operate at low inlet head and high suction head. This enables the exclusion of closed spiral casing. Also, the constant thickness blades enable the use of forging process instead of casting of complex airfoil blades. This leads to considerable reduction in manufacturing cost and complexity. A 1kW prototype was designed and scale down model of 185W was fabricated and tested. The runner consisted of five blades of 4mm thickness with camber and twist. The runaway speed of 1058 rpm was attained at design flow rate of 25 l/s. At full load the efficiency of model was found to be about 57%. Applying scaling effects the expected efficiency of the prototype was estimated to be about 60%. DOI: http://dx.doi.org/10.3126/jie.v9i1.10669   Journal of the Institute of Engineering, Vol. 9, No. 1, pp. 36–53

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