Water Turbine Research Articles

Gravitational Vortex Water Turbine (GVWT) Conical Basin Design: the Effects of Cone Angle and Outlet Diameter on Vortex Characteristics

A Gravitational Vortex Water Turbine (GVWT) seems to be a promising technology for low-head hydropower applications. The basin of GVWT plays an important role in the vortex formation as well as its performance. This study aims to analyze the effect of basin design on vortex characteristics in the GVWT. A conical basin is chosen due to the good quality of the vortex. The lab-scale experiment and Computational Fluid Dynamic (CFD) simulation was conducted to gain deeper insight into the effect of cone angle (θ) and basin diameter ratio (d/D) on the vortex characteristic, including air-core diameter, vortex height, and tangential velocity. Both parameters play a major role in regulating the water level and tangential velocity in the basin. The current work shows that the smaller the basin diameter ratio (d/D), the higher the vortex height, leading to a decrease in tangential velocity and vortex strength as the kinetic head is converted to a potential head. Moreover, basin parameters, including the vortex height and tangential velocity, fluctuate due to the variation of cone angle. According to this work, the conical basin with a large cone angle of 20° and a small d/D of 0.2 is suggested, since it produces a vortex with height tangential velocity and vortex height.

Exploring the potential of artificial intelligence tools in enhancing the performance of an inline pipe turbine

In this study, investigations were conducted using computational fluid dynamics (CFD) to assess the applicability of a Francis-type water turbine within a pipe. The objective of the study is to determine the feasibility of implementing a turbine within a pipe and enhance its performance values within the operating range. The turbine within the pipe occupies significantly less space in hydroelectric power plants since a spiral casing is not used to distribute the flow to stationary vanes. Consequently, production and assembly costs can be reduced. Hence, there is a broad scope for application, particularly in small and medium-scale hydroelectric power plants. According to the results, the efficiency value increases on average by approximately 1.5% compared to conventional design, and it operates with higher efficiencies over a wider flow rate range. In the second part of the study, machine learning was employed for the efficiency prediction of an inline-type turbine. An appropriate Artificial Neural Network (ANN) architecture was initially obtained, with the Bayesian Regularization training algorithm proving to be the best approach for this type of problem. When the suitable ANN architecture was utilized, the prediction was found to be in good agreement with CFD, with an root mean squared error value of 0.194. An R2 value of 0.99631 was achieved with the appropriate ANN architecture.

A walking energy harvesting device based on miniature water turbine

The rapid development of wearable electronics highlights the urgence to develop the portable energy harvester with excellent output performance, comfortability, and sustainability. This work designs an electromagnetic walking energy harvester based on water turbine that can be embedded in shoes with good comfortability. Its working principle is that the walking generated pressure energy drives a miniature hydraulic turbine to output electricity. Experimental results show that an average power of 300 and 180 mW can be produced at heel and toe, respectively, when a man of 80 kg walks at a speed of 1.8 m s−1. This power output exceeds the piezoelectric, triboelectric, and electromagnetic walking energy harvesters reported in the past. Additionally, the simpler structure endows it better comfortability as compared with the electrostatic capacitances. Computational fluid dynamics simulations provide a further insight that the efficiency of turbine can reach 13.5% by optimizing parameters of blade number and outlet flow ratio. Finally, user real-time positioning and trajectory recording are successfully demonstrated via a wearable GPS means Global Positioning System module powered by the harvester. Due to the combination of high output performance, simple structure and low discomfort, the water turbine based walking energy harvester will provide a wide application potential in wearable devices.

Significance of mixed convective double diffusive MHD stagnation point flow of nanofluid over a vertical surface with heat generation

The mixed convection double-diffusive MHD flow of boundary layer nanofluids above vertical region is designed. This flow is explained near stagnation point along with heat generation. Using Buongiorno’s model, the properties of Brownian motion, thermophoresis, and diffusion of regular and cross type are included. Using appropriate similarity transformations of the local similarity technique, non-linear unstable PDEs in governing model converted to non-linear ODEs, which were then evaluated numerically by the Keller-box method (KBM) using the computational software MATLAB 2021a. Graphical analysis of possessions of parameters on the boundary layers in profiles of velocity, solute concentration, temperature and nanoparticle concentration is illustrated. The statistics of the reduced Sherwood number and the reduced Nusselt number for solute and nanoparticles in cases of assisting flow and opposing flow are added as well to the results. The fastest rate of heat transfer is achieved in a scenario with a negligible thermophoresis effect. The thermophoresis parameter and the buoyancy parameter of the regular double diffusive appear to rise rather than decrease in the nanoparticles lowered Sherwood number, while the Brownian motion parameter rises. The temperature and layer thickness for heat generation have a quite opposite effect. When the computed numerical findings are compared to earlier published work, it is discovered to be in good percentage. The need for numerous industrial applications and improvements in the efficiency and energy consumption of systems, such as cooling and heating transportation, in water heaters, nuclear reactors, optical devices, turbines, aerodynamics, and electronics, have led to the establishment of this investigation.

Numerical simulation of a novel small water turbine generator for installation in a deep-flow hydroponics system

Hydroponics systems are crucial for providing sustainable and cost-effective choices when soils are unavailable for conventional farming. The application of water flow rates within hydroponics systems to generate electricity is another idea that can be used in the field of power generation. This paper presents the determination of the mechanical power efficiency of a novel small water turbine generator for use in a deep-flow hydroponics system (DFT). The system was designed, analysed, and calculated for the most suitable geometries of the water pipeline inlet, DFT system, main structure of the PVC Tee Pipe Fitting, and a water turbine wheel using computational fluid dynamics software. The diameter of the water turbine wheel in this research was 48 mm. A DFT hydroponic system was modelled for the purposes of this research. We conducted a numerical simulation with water flow rates of 6, 8, and 10 l/min to evaluate the turbulent kinetic energy distribution in the DFT hydroponic system. The numerical simulation employed the control volume methodology, and the k-epsilon turbulence model was applied to obtain the computational conclusions. The highest torque and power that a novel small water turbine for installation in a DFT system could generate at a maximum flow rate of 0.000167 m3/s were 0.082 N.m. and 1.9568 watts, respectively. The forces generated by the fluid's speed and pressure can then be transferred to the building process of a novel small water turbine wheel. The FEA numerical result shows that the maximum value of the total deformation at a wheel speed of 228 rpm is 7.0 x 10-5 mm. The numerical simulations used in this study could potentially be used to further develop prototypes for innovative miniature water turbines that generate commercial electricity.

An Increase in the Energy Efficiency of Vortex Micro HPP with a Flexible Outlet Siphon by Self-Adjustment of Flows in the Pressure Chamber

The article aims to increase the energy efficiency of the vortex micro-power plant, which would be achieved due to its compatibility with the terrain. In particular, the inlet channel connected to the water intake of the pressure chamber and the water collector placed in the upper pool by transverse joints, and the flexible siphon connected by vertical and horizontal joints to the diffuser of the same chamber with a telescopic end. The boundary conditions were selected with parameters such as the water flow acceleration according to the river bed’s slope angle and the inclination angle of the upstream channel near the vertical pressure cone chamber. The level difference between the upper and lower pools was adjusted. Inside the pressure chamber, the inclined guides of the small wings were hinged to its wall and were adjusted by ballasts. The reactive forces generated by the upward reflection of the incoming flow from the surfaces on the inclined small guide wings of the pressure chamber were a factor in curbing the said flow (compensating for the insufficient volume flow) and ensuring the continuity of the water supply to the turbine in shallow water. The mentioned circumstances allowed for improving the synchronization of incoming and outgoing flows. As a result of the above improvements, an increase in the energy efficiency (i.e., annual electricity generation) of 15–20 % was achieved.

Energy indicators of the micro-hydro power plant adjusted to outlet water flows from pump units

The article presents the prospects and main directions of the development of the use of hydropower sources, the parameters of the micro-hydro power plant, which works efficiently in variable and low-pressure water flows from the pumping units, and the results of the experimental studies of the micro-hydro power plant are presented. The developed vertical-axis micro-hydro power plant consists of a propeller-type hydro turbine with a diameter of 0.5 m, a bushing with a diameter of 0.2 m, and 6 blades with an optimal installation angle θopt=202.50°. It was determined that the maximum power of the micro-HPP is 3 kW and efficiency of the micro-HPP is equal to 0.88. Experimental work was carried out on the device, based on processing the results of the experiment, an empirical equation was obtained that determines the change in water flow consumption and turbine rotation speed of the mechanical power of the hydro turbine, and the significance of the regression equations was evaluated using Fisher‘s F-criterion. The significance level is 0.05 and at the number of degrees of freedom γ1 =63, γ2 =59 the calculated value of Fisher‘s F-criterion (Fcal= 1.03) is smaller than the value in the table (Ftab= 1,53), so the constructed regression equation is significant. The relative error of the calculation is ± 6 %. The proposed micro-HPP has the possibility of uninterrupted supply of electricity to electricity consumers in remote areas that are not connected to the centralized electricity supply system.

Open channel velocity field investigation for hydrokinetic power generation

The paper presents an experimental study of a velocity field in an open channel. The study of water flow in an open channel is complicated due to the influence of various factors and different variables. Some of the variables affecting the flow parameters include the height of the water column, the width of the channel, the length of the channel, the slope of the channel, and the conditions of the channel bed. The investigated open channel is used for experimental research of kinetic turbines, and the flow speed in the channel is in the range of 0.1-0.3 m/s. The low velocity values in the channel are driven by the operation of the kinetic water turbines in real-world conditions. When describing the test channel, the influence of several boundary conditions has been taken into account, such as protrusions between the measurement sections, the water level, and disturbing effects. Results for the velocity fields determined in five sections of the test open channel are given. A turbine and an electromagnetic probe were used for the experiments. A comparison between the results obtained with the two measuring instruments under the same flow conditions in the test channel is made. The results for the velocity variation in the test sections for the maximum velocity in the channel are presented. At this maximum water velocity, the test channel maintains a water level of approximately 150 mm. The experimental data is also illustrated graphically, along with the velocity fluctuations along the channel centreline. The results obtained provide an idea of the expected velocity fields in the measurement open channel and the relative magnitude of the fluctuations in the different measurement sections.

Experimental Study on Performance of a Hydraulic Francis Turbine with Variations of Runner Speed

This investigation was carried out to evaluate the characteristics of a Francis water turbine. Several variations of inlet valve openings of the turbine were tested to determine the effects of changes in rotational speed of runner on turbine performance. The method used in this study was experimental measurement using a test rig installation in Diponegoro University. The results found that discharge was not change significantly with increasing speed. The torque decreases as the turbine rotational speed increases. The break horse power (BHP) and efficiency curves are nearly identical. Both BHP and efficiency increase when speed are increased until the maximum condition is reached, then from this maximum condition, as speed increase, the BHP and efficiency gradually decrease.

Performance Analysis of the Archimedes Double Screw Turbine as a Micro Hydro Power Plant with Varying Flow Rate

Samadua is an area in South Aceh Regency which has a lot of water energy potential to be used as energy to drive water turbines. The potential for water energy, it is necessary to develop renewable energy power technology, namely micro hydro power plants that can be utilized by the community. The type of water turbine that is suitable for application in the area that have water potential with low head and discharge is the Archimedes Double Screw Turbine. The Archimedes double screw turbine is a type of turbine that capable of operating with a low head of 1-15 m in river flows and irrigation and has the advantage of being environmentally friendly. The aim of this research is to design and manufacture an Archimedes Double Screw turbine that is appropriate and in accordance with the real conditions in the stream of Samadua river, -South Aceh, then analyze the influence and determine the torque ratio on the performance of the Archimedes Double Screw Turbine by measuring rotation speed, torque, power and efficiency based on variations in river flow rate. The Archimedes Double Screw turbine is made from 201 stainless steel which has dimensions of N = 2 blades (= 260 mm, = 140 mm) with a pitch of 2Ro, turbine length (L = 2 m), head = 1 m, angle θ = 300. The variables measured and observed are turbine rotation, torque, and flow rate. Tests were carried out on 3 variations of flow discharge, namely 0.02 m3/s, 0.009 m3/s, and 0.003 m3/s. The test results showed that the highest turbine rotation and power occurred at a flow rate of 0.02 m3/s of 292.10 rpm and 122.20 watts and the maximum turbine efficiency was 62%. Thus, the turbine with maximum power is obtained when the flow rate is 0.02 m3/s, while the turbine with maximum efficiency is obtained when the flow rate is 0.02 m3/s. For the numerical simulation results, the optimum pressure distribution value is 4.873 kPa and the minimum is 0.1536 kPa, so the comparison of the experimental results with the numerical simulation is that the numerical simulation optimum torque value is 2.50 N/m and the experimental optimum torque value is 2.00 N /m.

Investigation on reuse of energy at a sewage treatment plant and payback period

AbstractThe reuse of energy is a topic currently being widely discussed around the world. This study analyzes the potential for energy reuse in treatment plants. Sewage Treatment Plants are responsible for treating the water present in the sewers of cities. The treated water returns clean to the river, and generally, the place of discharge has a high height and flow rate that can be harnessed for the generation of electric energy. This work investigates the feasibility of installing a Micro Hydroelectric Plant in the Treatment Station of the Uberaba River in Brazil. Hydraulic potential and investment analysis were used as viability criteria. For the study, a height of 6 m and an average flow rate of 0.465 m3/s were considered, which could generate about 22.51 kW using a Bulb water turbine. This power represents a return of US$1651.26 per month from the generation of electric energy. The estimated installation cost was US$32,966.73, and the payback period was found to be less than 2 years. There are 702 sewage treatment plants in Brazil alone, and hypothetical analyses were performed with flow rates ranging from 0.2 to 1 m3/s and heights ranging from 1 to 9 m. Motivating results with payback periods of less than 4 years were obtained for numerous hypothetical situations, which demonstrates the feasibility of installing Micro Hydropower Plants and achieving savings in the sewage treatment system.

Power Generation Prediction for Photovoltaic System of Hose-Drawn Traveler Based on Machine Learning Models

A photovoltaic (PV)-powered electric motor is used for hose-drawn traveler driving instead of a water turbine to achieve high transmission efficiency. PV power generation (PVPG) is affected by different meteorological conditions, resulting in different power generation of PV panels for a hose-drawn traveler. In the above situation, the hose-drawn traveler may experience deficit power generation. The reasonable determination of the PV panel capacity is crucial. Predicting the PVPG is a prerequisite for the reasonable determination of the PV panel capacity. Therefore, it is essential to develop a method for accurately predicting PVPG. Extreme gradient boosting (XGBoost) is currently an outstanding machine learning model for prediction performance, but its hyperparameters are difficult to set. Thus, the XGBoost model based on particle swarm optimization (PSO-XGBoost) is applied for PV power prediction in this study. The PSO algorithm is introduced to optimize hyperparameters in XGBoost model. The meteorological data are segmented into four seasons to develop tailored prediction models, ensuring accurate prediction of PVPG in four seasons for hose-drawn travelers. The input variables of the models include solar irradiance, time, and ambient temperature. The prediction accuracy and stability of the model is then assessed statistically. The predictive accuracy and stability of PV power prediction by the PSO-XGBoost model are higher compared to the XGBoost model. Finally, application of the PSO-XGBoost model is implemented based on meteorological data.

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°.

Perancangan dan Analisis Daya Turbin Air Piko Hidro untuk Aliran Arus Rendah

Over time, the consumption of electrical energy needed in Indonesia is getting bigger. Various efforts continue to be made either by seeking new energy potential or by developing existing technologies. Apart from the increasing need for electrical energy, efforts are made to supply the needs of electrical energy by utilizing the potential and conditions that exist in certain areas. Water energy has been widely utilized and used for power generation. The potential of water as an energy source can be used as a provider of electrical power. One of the uses of water energy is to make hydroelectric power plants. The purpose of this study is to design a portable water turbine design and find out the results of the calculation of the analysis of electrical power produced. The research method used is the analysis of water turbine design using the SolidWorks application to be able to find out the shape of the turbine that has simple, portable properties and can be carried anywhere. The size that meets the desired criteria is 10 cm for diameter and 4 cm for height. After designing the turbine design, then the calculation and analysis of the power released by the water turbine is carried out. The data needed to perform the calculation are water discharge 1.48×10-5 m3/s, head 6×10-2 m, water density 1000 kg/m3, gravity acceleration 9.81 m/s2, turbine efficiency 12.6%. Using the turbine power formula, the turbine power with a water discharge value of 1.48×10-5 m3/s is 11 Watts. Then the 2nd calculation was carried out with the value of the water discharge used of 9.6×10-5 m3/s and turbine efficiency of 24.9%. After calculation, the turbine power value of 14 Watts was obtained.

Insights into the nonlinear dynamic characteristics of a water turbine generator set considering the coupled effects of a fractional-order broadband foundation

The analysis of the coupled shaft-foundation system (CSFS) of a water turbine generator set is an extremely complicated task owing to its structural complexity and inherent nonlinear broadband dynamic characteristics. Thus, the coupling relationships of the CSFS remain unclear. The broadband vibration of the foundation subsystem has an evident influence on the vibration of the shaft subsystem of the unit; however, for the analysis of the dynamic characteristics of the water turbine generator, an overly complicated foundation can be reasonably simplified. To this end, this paper reports the development of novel energy-equivalent broadband modeling approaches to investigate the nonlinear vibration characteristics of CSFS. First, a relatively traditional integer-order lumped parameter model of the foundation subsystem was constructed, and its parameters were determined by fitting the response spectra obtained from an accurate hydropower house model. To improve the narrow-frequency limitation of the integer-order model and account for random disturbances, a novel fractional-order broadband modeling method is proposed. The advantage of the proposed fractional-order equivalent foundation model is that it can simultaneously reveal the broadband characteristics of complex structures at low frequencies of less than 1 Hz to high frequencies of hundreds of Hz with a single degree of freedom. Finally, coupled dynamic equations for the fractional-order CSFS model were derived and solved by considering the actions of various nonlinear factors and hydraulic pulsation excitation. A comparison of the dynamic responses of the CSFS with field test data demonstrated the effectiveness and practicability of the proposed modeling approaches. The results of the integer- and fractional-order CSFS models provide insights into the abundant dynamic laws and inner mechanisms of the nonlinear coupled dynamic system. Furthermore, they provided a reliable theory for the design and stability analysis of a hydropower unit, considering the varied vibrations of the coupled foundation.

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.

The effect of number of blades on the horizontal axis water turbine performance

Electrical energy is energy the main essential needed in living life for various aspects of utilities related to electronics with the provisions of the need for electric power consumption in units of Watts (W). The consumption for electrical energy is increasing along with the increasing population in this country. In 2020 the installed capacity of power plants in Indonesia will reach 72,750.72 MW consisting of 43,186.53 MW from National Power Plant (PLN) and 29,564.19 MW from non-PLN. Whereas in 2019 it was only 69,678.85 MW. This data shows that the installed capacity of power plants has increased by 3,071.87 MW. Therefore, this research aims to develop the horizontal axis water turbine and to investigate the performance of turbine with varying the number of blades. The experimental rig was built to conduct the experimental work. It is found that the most optimal number of blades is the number of blades 10 which produces a value of 0.704 Watt and speed of 789 RPM using a water discharge of 11.75 Liter per Minutes (LPM), 0.855 Watt and speed of 883 RPM using a water discharge of 13.22 LPM, and 0.889 Watt and speed of 913 RPM using a water discharge of 15.17 LPM. Electrical efficiency tends to decrease when the number of blades on turbine is increased due to a significant increase in speed of turbine with increasing of blade number while the electrical energy produced by the generator is relatively constant with increasing the blade number of turbine.

Parametric comparison of different lobe rotor geometry for positive displacement turbine in water distribution network

The application of hydro turbines for harnessing water energy within distribution networks, as an alternative to pressure relief valves, is steadily increasing. These turbines are particularly suitable for recovering energy from incompressible subsonic fluid flows. In this research paper, three models of positive displacement lobe machine designed to function as water turbines were extensively examined and compared. The three selected turbine types included the circular lobe turbine, the cycloidal arc lobe turbine and the epicycloid arc lobe turbine. These turbines were meticulously designed and developed for their respective applications. Under identical operational conditions, optimization processes were applied to enhance volumetric efficiency and power efficiency for all three turbine variants, each having a different number of blades. A computer program was devised to facilitate the optimization and calculation of blade geometries under various operating conditions. This research delved into the impact of blade geometry type and the number of blades on turbine efficiency and size. The data obtained from the present investigation were systematically analyzed, and the performance of the different turbines were compared. Notably, the circular lobe turbine was found to be the largest among the three, occupying more space. The cycloidal arc requiring a greater amount of material resulting in rotor volume, which subsequently resulted in a higher overall cost. In contrast, the cycloidal arc lobe turbine emerged as the smallest variant, demanding less space for operation. Efficiency-wise, the cycloidal arc lobe turbine exhibited the highest efficiency with two blades, while the circular lobe turbine displayed the lowest efficiency with six blades. Moreover, among the turbines with the same number of lobes, the cycloidal arc lobe turbine consistently demonstrated superior efficiency compared to the circular lobe turbine.

Comparison of Pressure Pulsation Characteristics of Francis Turbine with Different Draft Tube Arrangement Direction

Hydroelectric power generation is an important clean energy source, and the stability of water turbine operation determines the quality of hydro energy utilization. For hydro turbines, the layout direction of the draft tube is often only considered from a structural perspective, ignoring the hydrodynamic characteristics. This study adopts the computational fluid dynamics method and verifies the effectiveness of numerical simulation with experimental results, analyzing the influence of asymmetric draft tube layout direction on pressure pulsation of mixed flow turbine. The results show that under different working conditions, there is basically no difference in efficiency corresponding to different inclined directions of the draft tube, and the relative difference in performance values is less than 1%. From the perspective of internal flow, the working condition has a greater impact on the flow, and the draft tube tilt has a smaller impact. Under strong swirling flow conditions in the draft tube, the variational mode decomposition of pressure fluctuation is carried out. Research has found 7 characteristic frequency bands including 140 Hz, 80–90 Hz, 40–46 Hz, 5.5–6.5 Hz, 2.5–3 Hz, 1.67 Hz, and <1 Hz. The frequency of the dominant mode corresponding to the left tilt is higher, while the amplitude of the runner frequency is slightly lower. In general, left tilt is not only more suitable for unit layout but also has a better effect on draft tube pressure fluctuation, which is worthy of application in engineering.

Analisis Variasi Jumlah Sudu Terhadap Torsi Yang Dihasilkan Pada Turbin Vortex

Water turbines, particularly vortex turbines, represent a promising alternative energy source with significant potential for development. Vortex turbines are a relatively novel type of water turbine, offering ample opportunities for further research. This study aims to assess the efficiency of different blade variations, specifically 3, 4, and 5 blades. Computational Fluid Dynamics (CFD) analysis was conducted using Solidworks 2022 software. The simulation results indicate that the torque values for 3 blades, 4 blades, and 5 blades were 0.26 Nm, 3.02 Nm, and 4.96 Nm, respectively. Efficiency calculations were performed using a formula, yielding efficiencies of 0.9% for 3 blades, 11.91% for 4 blades, and 20.74% for 5 blades. These results suggest that higher blade counts lead to greater efficiency.