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.

Study on Open Cross-Flow Runner for Environmentally Friendly Nano-Hydraulic Turbine Utilizing Waterfall (Influence of Waterfall Thickness on the Runner Performance)

2011 ◽  
Author(s):  
Masahiro Yamazaki ◽  
Shingo Oike ◽  
Shouichiro Iio ◽  
Toshihiko Ikeda
Keyword(s):  
Power Generation ◽  
Flow Rate ◽  
Flow Condition ◽  
Great Influence ◽  
Cross Flow ◽  
Environmentally Friendly ◽  
Hydraulic Turbine ◽  
Open Type ◽  
Low Head

The aim of this investigation is to develop an open type cross-flow runner for environmentally friendly nano-hydraulic turbine utilizing extremely low head waterfalls. The waterfall condition is strongly affected by weather, so flow rate changes frequently. It causes a decrease in runner performance because it does not have any flow adjusting mechanisms. It is, therefore, important to evaluate the runner performance against the change of flow condition for stable power generation. This study focused on the influence of waterfall flowing position and its thickness on the runner performance. An open type cross-flow runner was applied for waterfall generation. As a result, we found that the runner characteristic varied with the waterfall condition. In particular, the waterfall thickness has great influence on the runner performance. The value of CPmax reaches the highest value of 0.61 at Q = 3.0×10−3 m3/s.

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

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

Performance Improvement of Very Low Head Cross Flow Turbine with Inlet Open Duct

2014 ◽  
Vol 17 (4) ◽  
pp. 30-39 ◽  
Author(s):  
Zhenmu Chen ◽  
Patrick Mark Singh ◽  
Young-Do Choi
Keyword(s):  
Performance Improvement ◽  
Cross Flow ◽  
Low Head

Internal Flow Analysis on an Open Ducted Cross Flow Turbine with Very Low Head

2014 ◽  
Vol 17 (5) ◽  
pp. 67-71
Author(s):  
Qingsheng Wei ◽  
Yeong-Cheol Hwang ◽  
Young-Do Choi
Keyword(s):  
Flow Analysis ◽  
Cross Flow ◽  
Internal Flow ◽  
Low Head

scholarly journals Studies on cross-flow water turbines. (Further report, application to low head)

1987 ◽  
Vol 53 (491) ◽  
pp. 2078-2084
Author(s):  
Tomitaro TOYOKURA ◽  
Toshiaki KANEMOTO ◽  
Takaya KITAHORA ◽  
Norihito SHIRAISHI
Keyword(s):  
Cross Flow ◽  
Low Head ◽  
Water Turbines

Laboratory Investigation of Helical Strakes With Serrated and Twisted Fins to Suppress VIV

2019 ◽  
Author(s):  
Gustavo R. S. Assi ◽  
Tommaso Crespi
Keyword(s):  
Cross Section ◽  
Water Channel ◽  
Cross Flow ◽  
Reynolds Numbers ◽  
Offshore Structures ◽  
Incoming Flow ◽  
Water Currents ◽  
Vortex Induced Vibrations ◽  
Different Types ◽  
Helical Strakes

Abstract Slender offshore structures of a cylindrical cross section, such as drilling and production risers, are susceptible to vortex-induced vibrations (VIV) when exposed to water currents. The present work presents an experimental investigation of the suppression of VIV of a circular cylinder by means of three different types of helical strakes: (i) a strake with continuous blades, (ii) a strake with serrated blades (or fins) and (iii) a strake with serrated blades individually twisted in relation to the incoming flow. By altering the blade geometry to produce the twisted-bladed strake, it was possible to keep the same level of suppression of the cross-flow vibration achieved by conventional strakes, but reducing drag in 15%. Experiments have been conducted in a recirculating water channel at moderate Reynolds numbers.

Effect of Exit Blade Angle on the Performance of Cross Flow Hydro Turbine: A Numerical Study

2021 ◽  
Author(s):  
Nur Alom ◽  
Bikash Kumar Sarkar
Keyword(s):  
Power Plants ◽  
Numerical Study ◽  
Cross Flow ◽  
Low Flow ◽  
Maximum Efficiency ◽  
Blade Angle ◽  
Hydraulic Power ◽  
Ansys Fluent ◽  
Low Head ◽  
Hydro Turbines

Abstract Cross-flow hydro turbines (CFHTs) are generally used in micro hydraulic power plants due to their simplicity in design and fabrication, moderate efficiency, ease of maintenance. The CFHT can be used in low flow and low head conditions with an efficiency of around 90% at rated conditions. However, the efficiency of the CFHT can further be improved by changing its geometric parameters Hence, in the present investigation, 3D unsteady simulations are performed in order to locate the exit blade angle (β2) with the intention is to improve the efficiency of the turbine. In the proposed investigation, the multi-physics FVM solver ANSYS Fluent has been used with the help of the SST k-ω turbulence model to carry out the unsteady simulations. The 3D unsteady simulations are performed by varying the exit blade angle (β2) from 60° to 90° to improve its efficiency when the rotational speed is fixed with the number of blades being 20. From the unsteady simulations, the maximum efficiency of the CFHT is at the exit blade angle (β2) = 80°.

Sign in / Sign up

Export Citation Format

Share Document