Helical Savonius Research Articles

Savonius wind turbine blade selection based on computational fluid dynamics

The Savonius vertical axis wind turbine is widely used because of its simple design and efficiency at low wind speeds. The next development is the mini multi-blade Savonius helical wind turbine. At this miniature size, the performance of a mini multi-blade helical Savonius turbine due to variations in the number of blades and its impact on the energy produced has not been investigated in depth. Therefore, adjustments to the size and number of blades need to be made to optimize the performance of this turbine. The research aims to obtain the performance of the Savonius type S wind turbine with 3 blades and 4 blades using the CFD (Computational Fluid Dynamics) method. The main dimensions of the simulation model are the shaft diameter of 0.008 m, the outer diameter of 0.24 m, the height of 0.4 m, and the number of blades 3 and 4. The inner diameter of the 3-blade turbine is 0.21 m while the inner diameter of the 4-blade turbine is also 0.21 m. Both turbine models are subjected to wind speeds of 4 m/s, 5 m/s, and 6 m/s. Based on the simulation results, a turbine with 4 blades has more optimal performance compared to the 3-blade type. At a wind speed of 6 m/s, the 4-blade Savonius helical turbine produces a rotation of 498,215 rpm and a maximum power of 6,129 watts. Meanwhile, the Savonius turbine with 3 blades at a wind speed of 6 m/s produces a rotation of 545,655 rpm and a maximum power of 4,390 watts. This difference in performance shows the importance of adjusting the number of blades in wind turbine design to achieve optimal efficiency. This research provides useful insights for the further development of mini helical Savonius wind turbines in various wind conditions

Mathematical modeling and performance evaluation of Ducted Horizontal-axis Helical Wind Turbines: Insights into aerodynamics and efficiency.

With the escalating demand for energy, there is a growing focus on decentralized, small-scale energy infrastructure. The success of new turbines in this context is notable. However, many of these turbines do not follow many of the basic ideas established to evaluate their performance, leaving no precise technique or mathematical model. This research developed a Ducted Horizontal-axis Helical Wind Turbine (DHAHWT). The DHAHWT is a duct-mounted helical savonius turbine with a venturi and diffuser to improve flow. Unlike a vertical axis helical savonius turbine, DHAHWT revolves roughly parallel to the wind, making it a horizontal turbine. This complicates mathematical and theoretical analysis. This study created a DHAHWT mathematical model. COMSOL simulations utilizing Menter's Shear Stress Transport model (SST) across an incoming velocity range of 1m/s to 4m/s were used to evaluate the turbine's interaction with the wind. MATLAB was used to train an artificial neural network (ANN) utilizing COMSOL data to obtain greater velocity data. The Mean Average Percentage Error (MAPE) and Root Mean Square Error (RMSE) of ANN data were found to be 3%, indicating high accuracy. Further, using advanced statistical methods the Pearson's correlation coefficient was calculated resulting in a better understanding of the relationship of between incoming velocity and velocity at different sections of the wind turbine. This study will shed light on the aerodynamics and working of DHAHWT.

Numerical and experimental investigation for helical savonius rotor performance improvement using novel blade shapes

Wind energy is extensively invested as a renewable and clean energy source. Savonius wind rotor, as an energy converter, has the merit of being appropriate for specific applications. The current paper centers on the performance enhancement of a helical Savonius wind rotor through the blade shape modification. The basic objective is to assess and compare, numerically and experimentally, the performance of two rotors with novel blade shapes named delta bladed and two-stage delta bladed shapes in relation to a helical Savonius rotor. Numerical study was conducted using Ansys Fluent software. 3-D unsteady simulations were carried out through the use of the SST k-ω turbulence model based on the finite volume method solver. Aerodynamic flow and performance characteristics were investigated. Static and dynamic experimental tests were undertaken on a wind tunnel. An improvement in Cp by 22.58 % and 29.5 % for the two-stage delta bladed rotor and 19.35 % and 16.4 % for the delta bladed rotor over the helical Savonius rotor was recorded, respectively, numerically and experimentally. In addition, the self-starting ability as well as the aerodynamic flow characteristics of the helical rotor were enhanced with the novel blade shapes.

Numerical Model Parameters Choice of Helical Savonius Wind Rotor: CFD Investigation and Experimental Validation

Electrical power is essential for human beings welfare. The available wind as a clean and renewable source of energy has whetted extensive interest over decades. Savonius vertical axis wind rotor as an energy converter has the merit of being adequate for specific implementations owing to its lower cost and independency on wind direction. From this perspective, multiple studies have been conducted to boost its efficiency. This research work emphasizes on the helical Savonius wind rotor (HSWR). The basic objective is to investigate the impact of selecting the numerical model parameters on its aerodynamic and performance characteristics. Experimental tests were realized with a 3D printed HSWR in a wind tunnel. The experimental performances in terms of power, static and dynamic torque coefficients were addressed. Next, a numerical study was undertaken through Ansys Fluent 17.0 software. Grid, turbulence model and rotating domain size tests were examined. Good accordance was obtained, which validated the numerical model with an averaged error of 5%. The maximum power coefficient proved to be equal to 0.124 at a tip speed ratio of 0.73 and 0.1224 at a tip speed ratio of 0.69, respectively, numerically and experimentally

A hybrid wind and raindrop energy harvesting operating on Savonius turbine

In offshore environments, abundant wind and rainfall resources await development, representing significant untapped energy potential for powering Internet of Things (IoT) devices. Triboelectric Nanogenerators (TENGs) are particularly suited for capturing continuous motion in offshore environments, presenting a reliable solution for sustainable energy generation in IoT applications. Herein, we propose a wind-droplet hybrid generator (WDHG) tailored for adaptive environmental energy harvesting, explicitly targeting the demanding conditions prevalent in offshore environments. The WDHG combines the efficiency of a helical Savonius TENG with the versatility of an interdigitated electrode TENG, enabling simultaneous wind and rain energy harvesting. The helical Savonius TENG exhibits superior aerodynamic performance, producing an output power ranging from 0.39 to 2.10 mW with wind speeds increasing from 0.75 to 6.84 m/s. Additionally, the droplet TENG generates a power output of 35.90 mW/m2 under rainfall at 70 mm/min. Optimizations include not only the comparative analysis of helical Savonius turbines and the variation in pole-pair numbers but also adjustments in fluorinated ethylene propylene (FEP) film thickness and electrode gap length for interdigitated electrode, alongside the development of a tailored power management circuit (PMC) featuring dual bridge rectifiers, a buck circuit module, and a smart load switch. The PMC enables continuous operation of a low-powered digital thermohygrometer under conditions of 4.5 m/s wind speed, and drives a 20-second wake BLE server under 7.2 m/s wind speeds. Integration of the WDHG with offshore wind and raindrop extends energy harvesting capabilities, exhibiting a great potential of providing reliable power source for IoT devices.

Experimental Assessment of Suitability of Darrieus and Savonius Turbines for Obtaining Wind Energy from Passing Vehicles

The article deals with the results of a comparative analysis carried out on the construction of wind turbines applied in energy generation systems using the wind of passing vehicles. The structures of turbines with horizontal and vertical axes of rotation were considered. Vertical axis wind turbines (VAWTs) have been observed to operate in various wind directions, including highly turbulent winds. Therefore, for further experimental research, VAWTs have been selected, i.e., Darrieus and Savonius turbines and their modifications. For the purpose of experimental research, the authors developed and implemented their own laboratory setup. This setup enabled the measurement of quantities such as torque, power, and power coefficient and allowed for the determination of the start-up parameters of the investigated turbines. Moreover, as part of the research, wind speed was also measured in field conditions at a distance of 1 m from the expressway. The wind speed obtained from passing vehicles did not exceed 9 m/s. For this reason, the tests of the considered turbines using the experimental setup were performed for wind speeds in the range of 5.8–8.6 m/s. The investigations were conducted based on the obtained results, and it was concluded that the helical Savonius turbine possessed the highest efficiency (0.2047 from a wind speed of 5.8 m/s) in generating energy from the wind produced by vehicles traveling on roads.

Investigation of The Effect of Phase Angle on The Aerodynamic Performance of Three-Bladed Helical Savonius Wind Turbines Using Computational Fluid Dynamics Method

In this study, the effect of the phase angle of the semicircular blades between the stages on the aerodynamic performance of the three-blade, double-stage helical Savonius wind turbines (HSWT), which are vertical axis wind turbines, was examined by the computational fluid dynamics (CFD) method. In the Savonius wind turbine system, the drag force effect provides the most significant contribution to aerodynamic performance. Performance improvements that can affect drag force can provide significant advantages. For this purpose, three-bladed double-stage helical Savonius rotors with eccentricity L/H=1/2 and phase angles of the semicircular blades between the stages Ɵ=0°, 45° and 90° were designed. Solidworks R2018 is used for designs and ANSYS-Fluent 18.1 programs are used for analysis. The turbine with L/H=1/2 and Ɵ=90° was produced on a 3D printer and tested experimentally. Experiments were carried out in the T-490 air tunnel. The results obtained were used as a reference for numerical analysis and the ideal turbine model was tried to be determined. 10 different air velocities ranging between 3.83-20.35 m/s were used in the numerical analysis. As a result, an 11.64% increase in the drag force was observed by changing the phase angle from 0° to 45° in HSWT 1/2s. By changing the phase angle from 0° to 45° in HSWT 1/2s, a 10.77% rise in the drag coefficient was observed. It has been evaluated that the HSWT efficiency improved with the increment in drag force.

Numerical Investigation on Aerodynamic Performance of Helical Savonius Rotor Inspired by Natural Shapes

There have been extensive studies conducted on Horizontal Axis Wind Turbines (HAWT) at relatively moderate to high wind speed regions. However, such detailed investigations for Vertical Axis Wind Turbines (VAWT), specifically for low wind speed terrains are amply reported. This motivates us to conduct research to explore possibilities in improving performance of VAWT in low wind speed terrains, which is attempted in the present work. This is required due to the fact that most of regions do not have sufficient extractable wind energy due to low speeds. VAWTs can perform at such low wind speed, but are less efficient. Improving efficiency of VAWT will solve the purpose. Hence, the present study is aimed at finding the performance characteristics of VAWT for low Wind speed configurations. Various parameters affecting power generation are investigated. Numerical analyses on various configurations are conducted to study the effects of twist angle, free stream velocity, number of blades. Computational results obtained have been in good agreement with the established results for semi-circular Savonius rotor profile. The results suggest that for low wind speed terrains, there is a need to explore the combination of lift and drag type of profiles, which could be used for the utilization of available wind power. Hence, naturally inspired shapes (profiles) were investigated for the possible solution of combined lift and drag type wind turbines at low speeds. The blade shape for such combined lift and drag type wind turbine were deduced from the available literature. It is well established that the naturally inspired shapes as noted in sea conch follow golden ratio in its contours. The present study provides an insight on the characteristic curves of VAWT for low wind speed terrains, effects of various geometric and flow parameters suitable for low wind speed terrains.

Hybrid cross-flow hydrokinetic turbine: Computational analysis for performance characteristics with helical Savonius blade angle of 135°

Hybrid hydrokinetic turbine (HKT) performance can be maximized with the right design and flow characteristics, but they can only be determined through a methodical process. Specifically, a computational study of modified hybrid HKT has been conducted, considering the design factors (attachment angle; radius ratio) as well as the water flow speed. The computational analysis is performed on the different configurations of hybrid HKT under different flow parameters. The computational findings showed that these factors have an effect on the overall performance characteristics of hybrid cross-flow HKT. The hybrid HKT model performs optimally at a combination of parameters with attachment angle = 60°, v = 0 .5 m/s, radius ratio = 0.4, and TSR value = 0.9. It was also determined that compared to the models with a radius ratio of 0.2, 0.6, and 0.8, this hybrid HKT model is 40 %, 1.46 %, and 20.49 % more effective. The chaotic behaviour of flow across the rotor has also been visualized.

Pengembangan E-Modul Turbin Angin (Savonius Heliks) dengan Model 4-D Pada Mata Kuliah Energi Terbarukan di Prodi Pendidikan Teknik Mesin Universitas Sebelas Maret Surakarta

Renewable energy technologies are currently being developed, one of which is wind turbines. There are two types of wind turbines, namely the vertical axis and the horizontal axis. One of the horizontal wind turbines is the helical savonius. The development of this technology can help the development of renewable energy. The Mechanical Engineering Education study program is testing wind turbines to help students understand wind turbine technology. Through this research a practicum module will be created to assist students in carrying out wind turbine practicum.This electronic module validates the material and media. The results of the material validation stated the suitability of the material in accordance with the material on wind turbines that had been taught in wind turbine courses. The results of the media validation state that the design is attractive and easy to read so that students can understand the electronic module.

Investigation of a helical Savonius turbine with a deflector system

The growing demand for renewable energy sources to meet electricity needs has underscored the importance of exploring new resources of renewable energy. Among the various alternatives, Helical Savonius rotors have emerged as one of the most widely used technologies for small-scale hydropower generation. Numerous studies have been conducted to investigate these types of rotors, particularly to enhance their power output. Despite existing research, there is still a need for modifications and proposals for new configurations of Savonius rotors. This paper presents a numerical study of a Savonius rotor equipped with a new design of a deflector. The results indicate that the highest power coefficient achieved is 0.1247 at a tip-speed ratio of 0.7 in the absence of a deflector system. The geometric parameters of the deflector are varied to identify the configuration that generates the highest power output. With the implementation of an optimal configuration for the new deflector system, the maximum power coefficient is improved to 0.168 at a tip-speed ratio of 0.7. Otherwise, the maximum power coefficient could be enhanced by 34% compared to the same configuration without a deflector. This significant improvement highlights the potential of the proposed design system.

Numerical Investigation of Hybrid Savonius-Darrieus Vertical Axis Wind Turbine at Low Wind Speeds

The need for electricity on the Earth is increasing day by day, and this requires building more electric power plants where most of the power plants cause CO2 emission which would increase the global warming. Using wind energy as one type of renewable energies, would contribute to reduce the global warming. In countries such as Malaysia where the average annual wind speed is 2-2.5 m/s using wind energy is a challenge because of the low wind speed. However, using a hybrid Savonius-Darrieus vertical axis wind turbine in low wind speed areas, the performance of the wind turbine may increase, and the starting rotation speed will decrease. This research aims at a comprehensive study on a hybrid Savonius-Darrieus wind turbine with helical Savonius rotor combined with helical and straight bladed Darrieus rotor. In this research, a base model with the name of Model Base was generated and two models with new configurations were generated in SOLIDWORKS. A numerical studies and simulation were conducted on these three designs using Ansys Fluent to identify the more suitable combination for low wind speed areas. Based on the obtained result hybrid Savonius-Darrieus with helical Savonius rotor and helical Darrieus rotor were found to be the most suitable combination because of their stable aerodynamic performance throughout a full rotation. Best performance for these models was found to be at 0.45 TRS with maximum torque and power coefficients of 0.68 and 0.306 respectively.

A comprehensive review on design and development analysis and blade material selection of helical Savonius rotor

The helical Savonius rotor (HSR) is used as green energy generation. The accurate design of HSR is essential before installing any wind farm in a region. It has been widely employed that positive static torque coefficients of helical Savonius rotor are higher compared to conventional semicircular rotor stated by several researchers. The reason is behind that the formation of secondary vortex of fluid. It is leading by vertical vortex flow, which passes over the curve surface and creates drag force. Still now, various design have been proposed to meet peak power output through optimum geometry parameters like blade profile design, aspect ratio and overlap ratio. The selection of blade material is also the influencing parameter to improve the starting torque of the rotor. In this regards present paper is aim to study the details experimental, numerical, and analytical review on HSR and selection of blade material with minimum production cost.

STUDI EKSPERIMENTAL PENGARUH JUMLAH SUDU DAN PENGGUNAAN END PLATE TERHADAP CUT IN SPEED TURBIN ANGIN SAVONIUS HELIKS

<p class="abstrak">This study aims to analyze the effect of variations in the number of blades and the use of end plates on the cut in speed of Helical Savonius wind turbine. The method used in this research is the experimental method. The variables used in this study are variations in wind speed from 1 to 5 m/s with intervals of 0.5 m/s. Variations in the number of blades are 2,3, and 4 blades. Variations in the use of end plates and without end plates. The results of this study was found that variations in the number of blades and the use of end plates affect the cut in speed of helical Savonius wind turbine. The fewer the number of turbine blades, the better the turbine's cut in speed will be. 2 blade’s Helical Savonius wind turbine with end plate is turbine variation that is able to produce best cut in speed of 1.97 m/s, compared to other variations.</p>

Design of type-2 fuzzy logic controller in a smart home energy management system with a combination of renewable energy and an electric vehicle

Home energy management is one of the most important parts of a smart home that manages the efficient use of energy in the smart home. This paper aims to design two type-2 fuzzy logic controllers in the demand-side energy management system. For this purpose, a combination of renewable energy sources, such as fuel cells, photovoltaic solar panels, vertical axis wind turbines with a helical savonius rotor, and an electric vehicle and energy storage system along with an external grid are utilized to supply the electricity usage of home appliances in a smart home. By using the proposed method, higher quality, more economical, and environmentally friendly energy can be accomplished. To this end, the outputs of the proposed controllers are defined to make appropriate decisions about the generated energy, how to supply energy for own consumption, and controllable loads. The number and distribution of membership functions of type-2 fuzzy logic controllers are selected according to the measured real input data over a year in Tehran, Iran. To demonstrate the effectiveness of the proposed method it is simulated by MATLAB/Simulink software, which indicates that the proposed system causes the smart home to receive 49.186 kWh less electricity energy from the grid to supply daily power for home appliances and therefore can weekly consume approximately 343.95 kWh less electricity energy from the grid. it is shown that after applying the proposed strategy, electricity costs were reduced by 71.5%, and the peak-to-average ratio was reduced by 64.6%.

Experimental and Numerical Investigation to Assess the Performance of Helical Bach Vertical Axis Wind Turbine at Low Wind Velocity Conditions

Abstract Many turbine models have been evolved to ameliorate the functioning of the small wind energy system. The newly developed helical Bach-type vertical axis wind turbine (VAWT) is used in this analysis with an idea to improve the overall performance. The shape of the conventional Bach-type vertical axis wind turbine is a modified form of a Savonius model which has both circular and straight portions to the blade profile. The simple Bach model has a maximum coefficient of performance corresponding to the blade arc angle of 45 deg and 225 deg. However, it consists of negative torque at the rotational angles of about 120–180 deg and 300–360 deg. Moreover, in the newly developed helical Bach, rotors can reduce the variation in torque in the rotational cycle; thereby, uniform torque is achieved in all angular position with improved performance. In this paper, experiments were conducted in the natural wind at Wind Turbine Research Station, Kayathar, Tamil Nadu, India. In addition to experimental work, the three-dimensional steady-state numerical investigations have been performed in the helical Bach vertical axis wind turbine. It is found that the numerical results are well matched with the experimental data. Based on the above computational study, it is found that helical Bach models have an increase in overall performance compared to the conventional Bach models and helical Savonius model.

A numerical investigation on the influence of savonius blade helicity on the performance characteristics of hybrid cross-flow hydrokinetic turbine

One of the major drawbacks of having a hybrid cross-flow hydrokinetic turbine (HKT) is the alternative nature (positive and negative) of instantaneous torque generation by blades over one cycle of revolution, which will reduce the power coefficient and raise the pulsation level of instantaneous torque. Under the present study, the physical configuration of the proposed hybrid cross-flow HKT is altered by replacing the conventional Savonius HKT blade with a helical Savonius HKT blade. The numerical simulations have been carried out for five different hybrid HKT configurations with different Savonius blade helicity values as 0°, 45°, 90°, 135°, and 180° for the considered range of in-stream velocity from 0.5 m/s to 2.0 m/s. Based on the numerical study, the maximum power coefficient of hybrid cross-flow HKT having Savonius blade helicity of 45° was obtained as 0.208 corresponding to a TSR value of 0.9 and in-stream water velocity of 0.5 m/s. It is improved by 4.5%, in comparison to the maximum power coefficient obtained from the hybrid cross-flow HKT having conventional Savonius blade under the same flow conditions. The torque pulsation level for different configurations of hybrid HKT has also been analyzed in this study. The maximum reduction in TPF was observed as 31.54% for a hybrid cross-flow HKT model with a Savonius blade helicity of 180°. Further, it is observed that the negative magnitude of instantaneous torque generated by hybrid cross-flow HKT having Savonius blade helicity of 135° and 180°, completely nullified and positive instantaneous torque is achieved for all the values of rotor angle over one cycle of revolution. The transient nature of flow across turbine blades has also been visualized through velocity and pressure contours.

Aerodynamic Performance of Vertical and Horizontal Axis Wind Turbines: A Comparison Review

The need for energy and electricity has been increasing globally, and this means more power is required from the power plants. Power plants, however, will then continue harming the earth because of the greenhouse gasses produced while generating energies that contribute to global warming. Using renewable sources to produce clean energies is one of the sustainable methods to deal with such challenges. Wind energy is one of the renewable sources, which is accessible anywhere on earth, creating green energy. Wind turbines are mainly categorized into Horizontal Axis Wind Turbines (HAWT) and Vertical Axis Wind Turbines (VAWT). This paper firstly presents a general comparison between the HAWTs and VAWTs. Then, it presents mathematical modelling for the aerodynamic factors of HAWT and Darrieus VAWT to assist the researchers to understand some key design aspects of wind turbines, such as lift/drag ratio, tip speed ratio, power coefficient, and torque coefficient. Also, this paper presents a review of the aerodynamic performance of the recent VAWT designs to help researchers to identify and choose the best model among the Savonius and Darrieus rotors for further development or designing a new model at different wind conditions. This comparison review shows that for a large scale HAWT upwind 3 bladed wind turbines are the most optimum. The helical Savonius rotors perform better by having positive torque coefficient at all azimuth angles. Moreover, helical Darrieus was found to produce lesser noise and suitable for conventional areas. hybrid Savonius-Darrieus rotors can solve the self-starting challenge of the VAWTs, and they are suitable at low wind speeds. At last, this review shows some of the recent hybrid Savonius-Darrieus rotors which would help to solve the low efficiency of Savonius rotor and self-starting challenge of Darrieus rotors.

Performance analysis of Helical Savonius Hydrokinetic turbines arranged in array

The Helical Savonius hydrokinetic turbines (HSHKT) are regarded as the beneficiary equipment to increase the power generation in low head rivers. This study investigates the performance of HSHKT arranged in arrays. Firstly, performance analyses of two HSHKT rotors are experimentally performed, arranged in inline formation along the fluid flow direction, for different spacing between them (L). These spacing are considered 3D (D = rotor diameter), 3.5D, 4D, 4.5D, 5D, and 5.5D. Experiments are performed in a hydraulic flume of 6 m length at 0.5 m/s velocities for different loading conditions. The optimum performance (i.e., coefficient of power and coefficient of torque) of both HSHKTs together is obtained at a distance of 4D. Consequently, the study is simulated through the ANSYS-CFX for 0.5 m/s upstream velocity and optimum performance is validated at L = 4D. Further, the study is extended in ANSYS-CFX for three HSHKTs arranged in arrays of different patterns, namely triangular and staggered formation. The analysis is performed for different velocities and varying distances between them. It is observed that at a 4D distance, the optimum performance of the three HSHKTs is achieved. Moreover, it is also found that HSHKT performance is better in staggered formation compared to the triangular formation.

Techno-economic analysis of a micro-hydropower plant consists of hydrokinetic turbines arranged in different array formations for rural power supply

This paper deals with the performance and techno-economic analysis of micro-hydropower plant consists of array of Helical Savonius hydrokinetic turbines (HSHKT). In this study, an optimal inter-turbine distance (L) and two specific HSHKT array formations, i.e., triangular and staggered are considered on a 69 m river stretch corresponding to a study area of 2.36 km2. River free stream velocity ranges between 0.88 and 1.88 m/s. Sensitivity analyses were carried out in HOMER software based on the free stream velocity and electric load to investigate the feasibility of the standalone hydrokinetic turbine renewable energy systems (RES) suitable for the rural community. Further, optimization analyses were performed considering minimum total net present cost (TNPC) and cost of energy (COE). The optimum RES consists of triangular formation of 24 numbers of HSHKTs, with 524 kWh/d electrical load, 187 numbers of battery and converter of 46 kW, having COE of Rs 8.22/kWh, TNPC of Rs 14.5 × 106 and electric production of 399.5 MWh/yr. TNPC and COE of triangular formation are 4.83% and 9.12% less than staggered formation, whereas electric production of the triangular is 4.99% more than the staggered formation. Thus, based on economic and energy indicators triangular array formation is considered as best for RES configuration.