Propeller-type Turbine Research Articles

Design of a recirculating water channel for the development of a hydrokinetic turbine

This study presents the design, construction, and operational details of an experimental recirculating water channel dedicated to the assessment of hydrokinetic turbines, including a propeller-type turbine and a H-Darrieus turbine, since it offers a controlled testing environment. The recirculating water channel had overall dimensions of 5 m in length, 0.35 m in width, and 0.5 m in depth, it allows for the replication of various water flow conditions and permits a maximum achievable flow velocity of 0.6 m/s, which closely resembles real-world scenarios. Afterwards, a propeller- type turbine and a H-Darrieus turbine underwent characterization within the channel, and a performance curve constructed through the coefficient versus the blade tip speed ratio (TSR) revealed a peak efficiency of 0.2129 at a TSR of 2.952 for the propeller turbine, and a higher peak efficiency of 0.3076 at a TSR of 0.38 for the H-Darrieus turbine. The versatility of this experimental setup makes it a valuable platform for in-depth performance studies of hydrokinetic turbines. This water channel and its systematic characterization process represent a vital resource for conducting efficiency and behavior analyses across a wide range of operational parameters related to hydrokinetic turbine technologies.

Simulation and experimentation of Propeller-Savonius turbine tested underwater surface

Abstract Indonesia’s vast maritime territory offers a unique opportunity for harnessing the potential Energy of seawater currents. This study explores the effectiveness of a combined Savonius and propeller-type turbine system. The Savonius turbine, known for its efficiency in capturing ocean currents due to its large sweep area, is combined with a propeller-type turbine to enhance rotational speed and power generation. A novel approach is employed to induce turbulence and optimize energy extraction, first channeling water through the propeller turbine and then into the Savonius turbine. A comprehensive investigation is conducted through simulations and experimental tests within a controlled tunnel environment. The study explores the performance of two-bladed and three-bladed Propeller-Savonius configurations at varying inlet water velocities (0.1, 0.3, 0.6 and 1.0 m/s). The simulation incorporates a turbulence model with 5% intensity and a hydraulic diameter of 0.216 m. Results indicate that the proposed configuration achieves a maximum power output of 2.0293 W with an impressive efficiency of 63.339% in simulation. Concurrently, experimental testing yields a peak efficiency of 61.335% and turbine power of 0.3951 W. The findings demonstrate the feasibility of the combined turbine system and highlight the importance of turbulence in optimizing energy extraction from seawater currents. This research contributes valuable insights into the design and performance of hybrid turbines for harnessing oceanic Energy, emphasizing the potential for sustainable power generation in maritime regions. The methodology and results presented herein offer a foundation for further exploration and refinement of seawater current energy conversion technologies.

Influence of Blade Number on the Hydrodynamic Performance of a Propeller-Type Axial Turbine for In-Pipe Installation

In-pipe hydraulic turbines are a promising energy-harvesting technology. Recent studies have demonstrated a strong influence of the turbine blade number on the performance of an axial propeller-type turbine. However, limited research has been dedicated to turbine diameters less than 100 mm. Therefore, this research aimed to determine the effect of the number of blades on the hydrodynamic performance of a 75.3 mm diameter axial propeller turbine for in-pipe installation. A parametric numerical study was performed by varying the angular velocity from 1600 to 3800 rpm and the number of blades from 2 to 6. Results identified an inverse correlation between the hydraulic efficiency of the turbine and its blade number and a direct correlation between the pressure head and the turbine torque. Furthermore, the performance showed hydraulic behavior comparable to those found in literature, confirming a similar hydraulic behavior as turbines with diameters exceeding 100 mm. Additionally, the turbine’s internal flow behavior was analyzed by visualizing the vortex structure using the Q-criterion. Lastly, this study provides a deeper understanding of the effect of the number of blades on the hydrodynamic performance of an axial turbine for in-pipe installation.

Propeller Turbine Design for Power Generation

The national electrification ratio is only 72.95%. As many as 27.05% of the territory in Indonesia has not been reached by electricity with various obstacles, one of which is because of the remote location so that access is difficult. One of the efforts to overcome the electricity problem is to take advantage of the potential energy sources around people's residences. One potential that might be used is a water energy source with low head and discharge. Ideally, this is done by using a generator system that uses a propeller type turbine. The difficulty of making propeller turbines is especially in the manufacture of housings and turbine blades. In this research, an attempt is made to simplify the turbine housing and turbine blades so that they are easy to manufacture. The design is made for Head (H) : 5 m Water flow (Q) : 0.11 m3/s Viscosity (ρ) : 998 kg/m3 Gravity (g) : 9.81 m/s2 Assumed hydraulic efficiency (ηh) : 0 ,80 Power (P) : 4,37 kW, Angle of attack (180o-β∞) 16o, Glide angle 55o, Thickness of inner blade(λ) 2,16o, Thickness of outer blade(δ) 2o. Simplification of the turbine housing is carried out by making the turbine housing from pipe iron and the simplification of the turbine blade is carried out by making turbine blades by eliminating the aerodynamic cross section of the blades, so that the blades can be made of steel plates without casting as is treated in aerodynamic sections. To see the effect of aerodynamic and non-aerodynamic cross-sectional shapes on efficiency, an efficiency test will be carried out.

Numerical Simulation of a Propeller-Type Turbine for In-Pipe Installation

In this work, a 76 mm diameter propeller-type turbine is numerically investigated using a parametric study and computational fluid dynamics. The three-dimensional model of the turbine is modeled using data available in the bibliography. A mesh independence study is carried out utilizing a tetrahedron-based mesh with inflation layers around the turbine blade and the pipe wall. The best efficiency point is determined by the maximum hydraulic efficiency of 64.46 %, at a flow rate of 9.72x10-3 m3/s , a head drop of 1.76 m, and a mechanical power of 107.83 W. Additionally, the dimensionless distance y+, pressure, and velocity contours are shown.

Characteristics of fluid exciting force due to blade row interaction of a propeller turbine

As the use of renewable energy is promoted, much researches on propeller-type turbines are carried out. To improve reliability, it is important to evaluate the fluid exciting force due to blade row interaction that may cause vibration or fatigue fracture. In this paper, CFD(URANS) simulations and experimental studies were conducted to understand the characteristics of the fluid exciting force due to blade row interaction of a propeller turbine. To evaluate the fluid exciting force, strain gauges and pressure sensors were used in the closed-loop water channel. The fluid exciting force acting on the rotor due to the stator was measured by changing stator load type and the rotor-stator distance. Based on the difference in the attenuation tendency of potential interaction and wake interaction due to changes in the rotor-stator distance, the influences of these interactions could be distinguished. As results of experiments and computation, wake interaction affecting pressure fluctuation was hardly attenuated due to the swirling flow and changing the rotor-stator distance has little effect on the attenuation of blade row interaction.

Development of a Hydropower Turbine Using Seawater from a Fish Farm

Discharge water from fish farms is a clean, renewable, and abundant energy source that has been used to obtain renewable energy via small hydropower plants. Small hydropower plants may be installed at offshore fish farms where suitable water is obtained throughout the year. It is necessary to meet the challenges of developing small hydropower systems, including sustainability and turbine efficiency. The main objective of this study was to investigate the possibility of constructing a small hydropower plant and develop 100 kW class propeller-type turbines in a fish farm with a permanent magnet synchronous generator (PMSG). The turbine was optimized using a computer simulation, and an experiment was conducted to obtain performance data. Simulation results were then validated with experimental results. Results revealed that streamlining the designed shape of the guide vane reduced the flow separation and improved the efficiency of the turbine. Optimizing the shape of the runner vane decreased the flow rate, reducing the water power and increasing the efficiency by about 5.57%. Also, results revealed that tubular or cross-flow turbines could be suitable for use in fish farm power plants, and the generator used should be waterproofed to avoid exposure to seawater.

Analysis of Ogan Ilir Regency's Kelakar River Runoff Discharge in Micro Hydro Power Plant (PLMTH) Planning

Micro hydro power plant (PLTMH) is an alternative source of electrical energy for the community where by using this PLTMH the community can utilize the existing river flow as electricity generation. The country of Indonesia has many rivers and creeks that can be used optimally in producing alternative electricity. Kelakar River, located in Ogan Ilir Regency has the potential to be developed as a Micro Hydro Power Plant (PLTMH) that can be used to supply electricity in the region around the Ogan River. Data analysis includes: catchman area analysis, rainfall analysis, calculation of rainfall intensity plan, calculation of runoff discharge, and analysis of river flow rates. Based on the analysis that has been done, the Kelekar river runoff discharge is QRmax of 211.109 m3/second and QRmin of 15.732 m3/second. From this result, the selection of turbines to be used in PLTMH planning is Propeller Type turbines.

Study of low head turbine propellers axial flow for use of micro-hydropower plant (MHP) in Aceh, Indonesia

Low head hydropower has the potential to produce green energy with a minimum on the environment and is one of the best choices for decentralized power plants. Aceh is one of many regions in Indonesia with hilly topography and many river streams. Of the 66 rivers in Aceh that have potential energy sources that can be developed 98.5 percent are low head. Generally, the technique for overcoming altitude problems in low river flows is the use of low head turbines. An important aspect of head power generation techniques is the selection of turbines. The study aimed to study low head propeller turbines for the use of micro hydropower plants. By calculating the main dimensions and main components of the turbine, field experiments were carried out to determine turbine rotation and energy, as well as turbine efficiency at a flow rate of 0.06 m3/sec and a 3.5-meter head. The calculation results obtained by a specific turbine speed of 1.53, runner diameter of 0.30 meters, hub diameter of 0.06 meters, shaft diameter 0.03, runner length 1.08, triangular speed of 30 degrees with the number of blades 4 pieces. From the results of field experiments, the maximum turbine rotation speed is 1828 rpm, the turbine power is 2,530 watts with a voltage between 220 to 240 volts while the maximum efficiency is 57 percent. It can be concluded that propeller-type turbines with the low head are suitable for micro power plants, especially in remote areas.

Flow and Fast Fourier Transform Analyses for Tip Clearance Effect in an Operating Kaplan Turbine

The Kaplan turbine is an axial propeller-type turbine that can simultaneously control guide vanes and runner blades, thus allowing its application in a wide range of operations. Here, turbine tip clearance plays a crucial role in turbine design and operation as high tip clearance flow can lead to a change in the flow pattern, resulting in a loss of efficiency and finally the breakdown of hydro turbines. This research investigates tip clearance flow characteristics and undertakes a transient fast Fourier transform (FFT) analysis of a Kaplan turbine. In this study, the computational fluid dynamics method was used to investigate the Kaplan turbine performance with tip clearance gaps at different operating conditions. Numerical performance was verified with experimental results. In particular, a parametric study was carried out including the different geometrical parameters such as tip clearance between stationary and rotating chambers. In addition, an FFT analysis was performed by monitoring dynamic pressure fluctuation on the rotor. Here, increases in tip clearance were shown to occur with decreases in efficiency owing to unsteady flow. With this study’s focus on analyzing the flow of the tip clearance and its effect on turbine performance as well as hydraulic efficiency, it aims to improve the understanding on the flow field in a Kaplan turbine.

Design and performance of composite runner blades for ultra low head turbines

Abstract Stream sites are abundantly available for small, ultra low head, hydropower applications with minimal environmental and ecological impacts compared to large-scale hydropower projects. However, little attention has been paid to these resources because of the relatively high weight and deployment costs of small turbines compared to the amount of power generated, which results from the use of stainless steel (SS) as the turbine material. Therefore, this study investigated the potential of replacing the machined SS blades in a small propeller-type turbine with light-weight composite blades injection molded from a fiber reinforced polymer. Using computational fluid dynamics models and finite element analysis, a carbon fiber-reinforced thermoplastic was selected from three candidate composite materials for its lower density and smaller blade tip displacement. Injection molded blades using this material were then manufactured and tested in a lab-scale turbine performance test loop to compare with the SS blades of the same design. With the same flow rates, the composite turbine blades generated more power but required a slightly higher head (∼0.08 m) than the SS blades. Both the composite and SS blades displayed similar peak turbine efficiencies, demonstrating the viability of the composite material in replacing SS from the perspective of power-generation performance.

Using Regulated Electrical Machines in Small Hydropower Plants Operating in a Power Network

Economic factors of operating hydroturbines used in small hydropower plants, including the Francis turbine, Pelton turbine, and axial Kaplan turbine with fixed blades (propeller turbine), are analyzed and compared as a function of the turbine-rotation frequency. It is found that the regulation of the turbine-rotation frequency depending on the changes in consumption of the energy carrier (water flow) improves the efficiency of the propeller turbines by 8–10% and leads to an increase in power production by the hydroaggregate as a whole. For these turbines, an expression describing the capacity (torque) as a function of the rotation frequency is obtained from the propeller characteristic of the turbine by approximating the frequency dependence of the turbine efficiency by a cubic polynomial. Since relative units were used, the obtained expression describes the characteristics of all propeller-type turbines. A mathematical model of an hydroaggregate consisting of a prototypical axial fixed-blade Kaplan hydroturbine coupled with a frequency-controlled synchronous generator with permanent magnets is developed. The study of static and dynamical operation modes of the above-mentioned hydraulic aggregate on the basis of this mathematical model verified the operability of the system and technical solutions used in its design.

Numerical simulation of a Savonius turbine above an infinite-width forward facing step

The Savonius turbine, although simple in construction, typically has a maximum power coefficient ( cP) of about 0.2. This is significantly lower than the cP of the axial flow propeller-type turbine which typically can be as high as 0.5. However, a simple means to improve the cP of a Savonius turbine is to install it above a forward facing step, for example, a cliff or a building. In this work, prior experimental results of the tow testing of a Savonius turbine installed above a finite-width bluff body were used to validate computational fluid dynamics simulation of the same experimental conditions. The validated simulation settings were then used to obtain the maximum cP of a similar turbine of finite width but installed above an infinite-width forward facing step over a range of installation positions above and behind the step.

A Review of Studies Relating to the Effects of Propeller-Type Turbine Passage on Fish Early Life Stages

Abstract Although few studies have been conducted to directly quantify ichthyoplankton mortality at hydroelectric installations, there is a considerable body of literature on examinations of the various stresses (i.e., pressure changes, blade contact, shear) that could affect turbine-entrained eggs and larvae. A review of these studies suggests that turbine-passage mortality of early life stages of fish normally would be relatively low at the low-head, propeller-type turbine installations (e.g., bulb or STRAFLO turbines), for which relevant design information is available. The shear forces and pressure changes in low-head bulb turbines are unlikely to cause ichthyoplankton mortality. Probability of contact with turbine blades is related to size of the fish; less than 5% of entrained ichthyoplankton would be affected. Potential additional sources of mortality related to the design and operation of hydroelectric facilities, and thus mitigable, include withdrawal of deep water and cavitation.

Specification Tolerance for Turbine Homology

Model tests of turbines are commonly used to determine the characteristics and particularly the expected efficiency of full size turbines. On some projects using propeller or kaplan type turbines, no accurate method of measuring the flow through the turbines is available. To assure that the full size turbine will perform in a homologuous manner with the model, tolerances for symmetry need to be established. Specifications are proposed for tolerance on the runner and on the fit of the wicket gates for large propeller type turbines.

Economic Aspects of Energy Generation: Hydro-Generation of Energy

The installed capacity of hydro-electric plants has been increasing almost continuously since 1900. Concurrently, the maximum size and horse-power of individual units have grown by leaps and bounds. The limit in efficiency was closely approached by 1920, and the most important event in the history of turbine design since that time is the development of the propeller-type turbine.

Hydraulic and Electrical Possibilities of High-Speed, Low-Head Developments

The paper deals with the change brought about in hydroelectric practise by the introduction of the high-speed low-head propeller type of turbine. For a given head, up to about 70 ft., it is possible to run the units at a much higher speed, thus reducing materially the cost of the generator. The maximum efficiency of the unit is maintained and the part load efficiency greatly improved by the use of adjustable blade turbines, so that there is also a material gain where variable load or flow is to be handled. The fundamentals underlying the design of an adjustable blade propeller type turbine are given and an illustrative study made of a three-unit station, to show the gain in output obtainable from this type of unit.

Greater efficiency for low-head hydro

For heads up to 70 ft. it is predicted that the automatic adjustable-blade feature of the Kaplan propeller-type turbine is capable of producing at least ten per cent more kilowatt-hours.