Cross-flow Water Turbine Research Articles

Study on the optimum design of cross flow water turbines using RSM with weighted least squares method

In this study, an optimum design method using the response surface method (RSM) was applied to a cross-flow water turbine in which a circular cavity was installed. The efficiency obtained by CFD analysis was used as the objective function. A quadratic equation for the shape parameters obtained using the weighted least-squares method was used to the response surface. For optimal nozzle design, three shape parameters were used: the runner opening angle, nozzle wall exit angle, and radius of curvature of the nozzle wall. In the weighted least-squares method, the weights of the residual between the efficiency obtained from CFD analysis and the value from the response surface were defined as inversely proportional to the root mean square of the difference between the efficiency of the calculation point from CFD and that at the highest efficiency point, such that more accurate optimal values could be estimated. The shape derived using this optimum method achieved high efficiency.

Cross-flow Turbine Design with Taguchi Method Approach

The current energy demand is very large, while the use of energy, which mostly uses petroleum and coal, is not matched by the availability of energy sources. For this reason, it is necessary to conduct research on alternative energy in order to provide energy security in the future. One alternative energy is water energy, which uses water turbines. This study aims to determine the optimum conditions for design parameters for static pressure and magnitude speed in crossflow water turbine design. The testing was done using finite element method simulation, namely Autodesk CFD. Taguchi methodology analysis is used as an optimization method. The number of blades, blade angle, and water direction angle were set as design parameters with constant water discharge parameters. The resulting static pressure and magnitude velocity were observed as design criteria. The results of the Taguchi method analysis in this study show that the optimum static pressure received from the water turbine is at the number of blades, with 10 blades, a blade angle of 22°, and a water direction angle of 60°. While the optimum velocity of the water turbine is at the number of blades of 6, the blade angle is 20°, and the water direction angle is 60°.

Preliminary theoretical design of crossflow water turbine for rainwater rooftop harvesting system

Harvesting energy is essential especially now that the demand of energy is high but the fuel supply is limited. This study theoretically designs the 5 m low head crossflow turbine in rainwater harvesting system. The characteristics of the site condition, the runner geometry, the blade geometry, and the turbine specification had been identified and the geometrical model of the design is shown. This paper reported the collection of theoretical formula for the design of low head crossflow turbine that can be used for rainwater harvesting system. The dimensional form of equations, as presented in Section 2, resulted to the two, four, and two parameters that represent the dimensions of the turbine, runner and the blade, respectively. As a conclusion, the designed turbine can be used for rainwater harvesting system with an efficiency that was calculated to be 88% with 22 kW expected power generated for 5 m head.

Experimental analysis of cross-flow wind turbine with omni-directional multi-nozzle

Using guiding devices is a method for increasing the efficiency of vertical wind turbines. The main problem of these devices is the hydraulic losses that occur from shading the turbine runner. Тhe geometry of the guide apparatus must ensure independence from the wind direction and allow free passage of the airflow through the blade cascade of the runner. This paper presents the results of a physical and numerical study of a cross-flow vertical wind turbine with an omni-directional guiding multi-nozzle. The task of the study is to determine the influence of the multi-nozzle on the efficiency of the turbine when the airflow changes its direction. The idea is inspired by the kinematics of the flow through the guide nozzle and runner of the cross-flow water turbine. The experiments were conducted in the Laboratory of Hydro Power and Hydraulic Turbomachinery (HEHT Lab) at the Technical University of Sofia. The obtained results are showing the influence of the multi-nozzle on the performance of the cross-flow wind turbine. They favour the selection of a suitable omni-directinoal guiding device for vertical axis wind turbines.

PERFORMANCE ANALYSIS AND OPTIMIZATION OF A HELICAL CROSS-FLOW WATER TURBINE

In this study, a Computational Fluid Dynamics model is designed to investigate the performance analysis of a helical cross-flow water turbine by using Comsol Multiphysics. In order to predict the main performance characteristics of turbine such as power output and torque, a numerical model is developed which is accurate, fast and quite simple to be used for a simulation. The flow field around turbine is solved with the Rotating Machinery feature in the Comsol CFD Module using a k-ω turbulence model and a steady state formulation. The Navier-Stokes equations are used in the model which are arranged in a rotating frame in the inner domain and in fixed coordinates in the outer domain. The boundary between the inner and the outer domain is a continuity boundary condition that transfers momentum to the fluid in the inner domain. This model also uses the Frozen Rotor study type which speeds up the computation time. Then, to increase the performance of the cross-flow water turbine, a new angular velocity profile is explored with Comsol Optimization Module. Thus, a variable speed turbine control method is developed. Compared to the constant velocity control method, new angular velocity control method yielded a 3% increase in the efficiency of turbine.

Optimization of inverse-Prandtl of Dissipation in standard k-ε Turbulence Model for Predicting Flow Field of Crossflow Turbine

Despite the successful use of the Standard model in simulating turbulent flow for many industrially relevant flows, the model is still less accurate for a range of important problems, such as unconfined flows, curved boundary layers, rotating flows, and recirculating flows. As part of the authors’ effort to extend the model applicability and reliability, this paper aims to study the effects of diffusivity parameter called the turbulent Prandtl number of dissipation rate () on the Standard model performance for predicting recirculating flow in a crossflow water turbine. The value of this parameter was varied from 0.5 to 1.5 in the CFD simulations, and the results were compared to the more sophisticated model, namely the RNG , which has been first qualitatively validated by an experimental result. In addition, the parameter value was also adjusted using the Multi-Linear Regression (MLR) method ranging from 0.42 to 1.5 to complement the CFD simulations. It was observed that reducing the value is effective in minimizing the average deviation of the turbulence properties concerning the RNG model. However, the adjusted model still faces difficulty in accurately predicting the pressure and velocity field. Based on this result, adjusting the constant in the Standard turbulence model has the potential to improve the model performance for modelling recirculating flow in terms of the turbulence properties, but still needs further investigation for the flow properties.

Frequency modelling and dynamic identification of cross-flow water turbines

The cross-flow turbines cover from the point of view hydraulic power the running domain of some well-known turbines such as Pelton, Francis or Kaplan. This type of turbine has a simple construction, long life and low execution cost, which makes it very suitable for on and off grid small to medium hydro power plants. It is quite difficult to establish an exact theoretical dynamic model for this type of turbines, due to the complex flow phenomenon (bi phase flow water and air). In order to obtain the exact dynamic behavior of the hydraulic machine, experimental dynamic identification will be done. In automation, the dynamic properties, represent the fundamental characteristic of the object which must be regulated. When the dynamic properties of the regulated object are obtained experimentally, we analyze the characteristics of the transient regime, which appears because of the application at the system inlet of some stochastic or deterministic signals (sine waves for our case). The hydraulic turbine is modeled as an informational quadrupole having the inlet parameters the movement of the wicket gate and the turbine head and outlet parameters the torque and the speed. In this paper it will be presented the frequency modelling of the cross-flow turbine and the validation of the mathematical model through experimental dynamic identification.

산간 지역 마이크로 수력 발전설비 구축

Hydropower energy is well known as clean renewable energy. In particular, hydroelectric energy has a great advantage in that it has high efficiency compared to other energy sources. In addition, it is possible to obtain stable and constant output at all times due to its high operating rate. Compared to other countries, Korea has mountainous terrain and many small rivers. In these sites, it will be possible to build a power generation facility with a micro-level output rather than a high power generation output.<BR>The most important factors in determining generator output are flow and head. In order to operate the generator most efficiently, a constant flow rate must be maintained at all times, and the amount of head must be be the same. In general, small rivers in rural areas have large fluctuations in flow rate. Therefore, the selection of the water turbine is very important.<BR>In this study, a cross-flow water turbine that can easily respond to changes in flow rate selected, and a squirrel cage induction generator was applied in consideration of economic feasibility and maintenance when selecting a generator.<BR>This research team compared and analyzed the difference between design and operation through simulation and measurement of the power and power factor obtained from the induction generator when it is installed and operated in the field after determining the output considering the flow rate and the head.

Research and Design of Cross Flow Water Turbines for Small HPP

This paper presents the experience of the Hydroaerodynamics and hydraulic machinery department of the Technical university of Sofia (Bulgaria) in the research and design of cross flow water turbines. The methods and computer programs used for the synthesis of the elements of the flow part of the cross flow turbines are described. Results of numerical and experimental (model and field) studies of turbines of this type are presented. The peculiarities of the elements of the designed turbines are analyzed and specific examples of their used in small hydropower plants in Bulgaria are shown.

Visualization and PIV Measurement of Internal Flow of Cross-Flow Water Turbine

Visualization and PIV Measurement of Internal Flow of Cross-Flow Water Turbine

PENGARUH SUDUT BUKAAN GUIDE VANE DAN TEKANAN AIR TERHADAP KECEPATAN PUTAR DAN DAYA OUTPUT PADA PROTOTYPE PEMBANGKIT LISTRIK TENAGA MIKROHIDRO DENGAN TURBIN CROSSFLOW

The pattern of power plants development in Indonesia is still relying on the availability of fossilfuels based energy sources. Meanwhile, Human are faced with a situation of depleting reserves offossil energy sources and increasing environmental damage due to the use of fossil fuels basedenergy sources. Renewable Energy development can be a solution to these problems. One of them isthe development of a Micro Hydro Power Plant. In the realization of Micro Hydro Power Plant inIndonesia, the crossflow water turbine type can be used. It is a type of impulse turbine with a goodcharacteristic at a low head for micro-scale generator capacity. This study analyzes the effect of guidevane opening angle and water pressure on rotation and output power of crossflow turbine. Theopening angle of the guide vane studied was 15º, 30º, 45º, 60º, 75º, and 90º in each water pressurecondition of 4 psi, 8.5 psi and 13 psi. The test is carried out by simulating direct measurements on theprototype of the Micro-hydro Power Plant that has been built. Every combination of parameterstested, the maximum value of rotational speed and output power is obtained at the guide vaneopening angle of 30º and water pressure of 13 psi. Turbine rotation values generated before and aftercoupled with a generator are 591.9 rpm and 522.7 rpm. The values of the generator rotation beforeand after the load coupled are at 3490 rpm and 2368 rpm. And the power value generated by thegenerator is 11.8 Watts.

Improvement of Performance of Undershot Cross-Flow Water Turbines Based on Shock Loss Reduction

Undershot cross-flow turbines are applicable to shallow open channel flows and are characterized by a simple structure free of guide vanes or a casing. Since these water turbines operate in a free surface flow field, the optimum inlet blade angle and outlet blade angle are considered to vary with the flow rate in the open channel; however, guidelines for setting these angles are yet to be established. In this study, a method to improve the performance of an undershot cross-flow water turbine based on shock loss reduction was proposed. First, by varying the blade angle of the straight blades of the turbine, the inlet blade angle and outlet blade angle which reduced shock loss in the first-stage inlet region and second-stage inlet region were investigated through free surface flow analysis. From the results, it was shown that by taking the inlet and outlet blade angles which minimize the first-stage and second-stage shock losses for straight blades and applying them to curved blades, shock loss is reduced, thereby improving turbine efficiency and turbine output.

Numerical Simulation of the Flow around a Straight Blade Darrieus Water Turbine

In this study, three-dimensional transient numerical simulations of the flow around a cross flow water turbine of the type H-Darrieus are performed. The hydrodynamic characteristics and performance of the turbine are investigated by means of a time-accurate unsteady Reynolds-averaged Navier–Stokes (URANS) commercial solver (ANSYS-Fluent v. 19) where the time dependent rotor-stator interaction is described by the sliding mesh approach. The transition shear stress transport turbulence model has been employed to represent the turbulent dynamics of the underlying flow. Computations are validated versus previous experimental work in terms of the turbine efficiency curve showing good agreement between numerical and experimental values. The behavior of the power and force coefficients as a function of turbine angular speed is analyzed. Moreover, visualizations and analyses of the instantaneous vorticity iso-surfaces developing at different blade rotational velocities are presented including a few movies as additional material. Finally, the fluid variables fields are averaged along a turbine revolution and are compared with the steady predictions of simplified steady approaches based on the blade element momentum theory and the double multiple streamtube method (BEM-DMS).

Effect of the Number of Blades on Free Surface Flow Patterns and Performance of an Undershot Cross-Flow Water Turbine with Straight Blades

Effect of the Number of Blades on Free Surface Flow Patterns and Performance of an Undershot Cross-Flow Water Turbine with Straight Blades

Performance test of Pikohidro Cross flow Water Turbine using multilevel double penstock

This study aims to examine the performance of pico hydro scale cross flow water turbines using multilevel double penstock as a conductor of water flow. Multilevel double penstock is used to reduce the transportation process from highways that are affordable to four-wheeled vehicles / cars to the location of the installation of the turbine. This condition causes the need for small-scale water turbine designs with lightweight construction with a kock down system. Overall the picohidro scale turbine construction is needed relatively cheaper transportation costs, so that people who have not been reached by the PLN network can be touched by small and cheap electricity. Turbine construction data has a runner diameter of 170 mm, body dimensions 200 mm x 300 mm x 250 mm, frame 250 mm x 800 mm. Pool tando 600 mm x 1200 mm and penstock length 16m. The power produced is theoretically around 2500 watts, with a data flow of 50 liters / second and a water level of 8 m. 65% efficiency. The research method is analyzing the double penstock water flow, by making paralon pipes in stages, ranging from 5 incci diameter, 4 inches and 3 inches, flow analysis approach using a gradient line, where the incoming water velocity and water velocity come out until entering the transmitting pipe. The performance results of this turbine provide an average actual power of up to 2000 watts. The stability of the inlet water condition is used by the Tando pond as a water bath. If there is excess water in the sediment tank, the water gate is used out, where excess water will automatically flow into the exhaust channel.

Effect of flow rate on performance and flow field of an undershot cross-flow water turbine

Undershot cross-flow water turbines are characterized by their being easily applicable to open channels with various widths and depths by changing their blade width and/or the outer diameter of the runner. On the other hand, as this water turbine operates in a free-surface flow field, it is expected that when the flow rate changes, the flow field around the runner including the water depth changes dramatically, and that the turbine performance also changes. Thus, the objective of this study is to elucidate the effect of flow rate on the performance and flow field of an undershot cross-flow water turbine. By changing the flow rate, we conduct experiments and free surface flow analysis on the water turbine, as well as torque component analysis. The result showed that, among the torques in the respective flow regions, that torque resulting from the second stage cross-flow was dominant. Furthermore, it was found that among the respective dynamic components of the torque, the most dominant component was the gravitational component for low flow rates and the angular momentum component for medium-to-high flow rates. We expect these results to contribute to the establishment of higher performance design guidelines, such as optimum shapes for the flow rates.

Effect of Blade Angle on Performance and Flow Field of an Undershot Cross-Flow Water Turbine with Straight Blades

Effect of Blade Angle on Performance and Flow Field of an Undershot Cross-Flow Water Turbine with Straight Blades

Pengaruh Sudut Pengarah Aliran Pada Turbin Air Crossflow Tingkat Dua Terhadap Putaran dan Daya

The potential of hydro energy is very large both for large scale and for small scale. Until now, the need for energy continues to increase, so that energy is a very important element in the development of a country or a region. Cross-flow turbines are one type of turbine that is often used for PLTMH. In this study planning a cross-flow water turbine applied to the height and amount of water per second in the irrigation channel water flow, this water flow will rotate the turbine shaft to produce mechanical energy. With variations in the direction of the turbine flow direction, namely 30o, 35o, and 40o, and the same variation of water discharge 10,5 L / s, 21 L / s and 31,5 L / s to determine the effect on the rotation and the power produced. In this study with 12 turbine blades, 30o blade angle, 40o flow direction angle, and 31.5 L / s water discharge obtained the highest first stage turbine rotation value is 478 rpm. Whereas at the flow direction angle of 30o with the same water discharge which is 31.5 L / s so that the first stage of the turbine is obtained is 296 rpm.

Numerical Simulation on Performance of a Cross-Flow Water Turbine

Numerical Simulation on Performance of a Cross-Flow Water Turbine

Identification and Control of a River-Current-Turbine Generator—Application to a Full-Scale Prototype

This paper reports on the operation assessment of an electrical power generation system based upon cross-flow water turbines. The specific power take-off system has been tested in real-world conditions in a variety of scenarios and the experimental results have confirmed previous modeling assessments. Dynamical proprieties have been precisely identified and stable system operation over the entire operating range has been achieved. Steady-state characterization in terms of power coefficient has also been done, allowing the assessment of power generation system global efficiency and enabling the building of more precise models to be used in further simulations and assessments for power grid integration. Maximum power point tracking and other specific operation regimes such as angular position synchronization have also been validated.