scholarly journals SIMULASI PENGGUNAAN DIFFUSER PADA TURBIN ANGIN SUMBU HORISONTAL UNTUK KENAIKAN DAYA

2012 ◽  
Vol 9 (1) ◽  
Author(s):  
Sulistyo Atmadi ◽  
Ahmad Jamaludin Fitroh
Keyword(s):  
Wind Turbine ◽  
Output Power ◽  
Flow Rate ◽  
Power Output ◽  
Area Ratio ◽  
Diameter Ratio ◽  
Speed Distribution ◽  
Ratio Variation ◽  
Air Speed ◽  
Cfd Method

 One technique to improve the power output of a wind turbine is by implementing a diffuser, which is called the diffuser augmented wind turbine (DAWT). The area ratio between the inlet and outlet of the diffuser increases the flow rate inside the diffuser which in effect produces higher output power. In this research, a 2 meters rotor diameter was used. Diffuser diameter ratio variation of 2, 3, 4, and 5 were chosen which provides inlet diameter of 4, 6, 8, and 10 meter respectively. Power rotor coefficient is assumed to be constant of 0.30. Air speed distribution inside the diffuser is calculated using CFD method. The inlet speed to the diffuser is varied to give 4 different speeds. The wind angle at the inlet is also varied at 0º, 30º and 60º. The simulation result showed that at 0 degree angle, diffuser diameter ratio variation of 2, 3, 4, and 5 will increase the power output about 58, 622, 3169, and 11519 times respectively. It also showed that the increase in the output power for diameter diffuser ratio of 2 at 0º and 60º angle is 58 and 4 times respectively. Keywords:Wind turbine, Diffuser, CFD

The Aerodynamic Analysis of Helical-Type VAWT With Semi Empirical and CFD Method

2019 ◽  
Author(s):  
Ying Guo ◽  
Liqin Liu ◽  
Xinxin Lv ◽  
Yougang Tang
Keyword(s):  
Wind Turbine ◽  
Output Power ◽  
Structural Parameters ◽  
Vertical Axis ◽  
Empirical Method ◽  
Parameter Analysis ◽  
Vertical Axis Wind Turbine ◽  
Parameters Analysis ◽  
Cfd Method ◽  
Semi Empirical

Abstract Comparing to Φ-type and H-type VAWT (Vertical Axis Wind Turbine), the amplitude changes of the aerodynamics acting on Helical-type VAWT are much smaller, so Helical-type VAWT has advantages in steady output power and avoiding fatigue of structure. Considering the characteristic of helical-type VAWT, this paper modifies the semi empirical method of calculating aerodynamic loads and compares with CFD results. A comparison is presented between CFD results and experiment results to confirm the model used in CFD. Single parameter analysis and muti-parameters analysis are carried out to study the influence of structural parameters on the dynamic torque. Based on an objective output power as 5MW, the parameters of wind turbine are adjusted, and optimal values of these parameters are determined.

PENGARUH PITCH SUDU TERHADAP KINERJA TURBIN ULIR

KURVATEK ◽  
2018 ◽  
Vol 2 (2) ◽  
pp. 111-122
Author(s):  
Harianto harianto Harianto
Keyword(s):  
Output Power ◽  
Flow Rate ◽  
Inclination Angle ◽  
Power Output ◽  
Energy Resources ◽  
Incline Angle ◽  
Hydro Power ◽  
Low Head ◽  
Outside Diameter ◽  
Turbine Output

Abstrak                Sumber tenaga air dengan head  rendah di Indonesia masih banyak yang belum termanfaatkan sehingga perlu dikembangkan dan dimanfaatkan secra optimal. Salah satu turbin yang mampu bekerja pada head  rendah adalah turbin ulir. Banyak parameter yang berpengaruh terhadap kinerja turbin ulir, di antaranya adalah jumlah sudu, jumlah lilitan, jarak antar sudu,  sudut kemiringan, dan debit. Sehubungan dengan hal ini maka perlu dilakukan penelitian untuk mengetahui harga parameter-parameter tersebut pada kondisi kinerja optimalnya.             Tujuan penelitian ini adalah untuk megetahui pengaruh pitch sudu , kemiringan sudu dan laju aliran air masuk terhadap putaran, daya output dan efisiensi turbin ulir. Penelitian dilakukan terhadap suatu model turbin ulir dengan dengan diameter luar ulir (d0) 10,10 cm, ulir tunggal ,  dan panjang ulir 43 cm, dengan variasi sudut kemiringan antara 100 sampai 450, variasi laju aliran air 84 l/menit, 95 l/menit dan 105 l/menit,dan variasi  jarak antar sudu (p) 2 cm, 3 cm , 4 cm Dari hasil penelitian ini diperoleh putaran maksimum 240 rpm pada laju aliran air 105 liter/menit ,   sudut kemiringan 20 0,dan pitch sudu 3 cm     menghasilkan daya maksimum 5,558 W dengan efisiensi maksimum sebesar 44,349. Kata-kata Kunci: turbin ulir, head rendah, daya, efisiensi ,pitch   Abstract   Indonesia has many low head hidro power energy  resources that have not been in use yet, so it is needed to be developed and exploited. One of the low head hydro power turbines is Archemedian srew turbine. There are many parameters and variables that influence to the performance of the turbines, such as number and pitch of blades, inclination angle, and flow rate.                The objective of the risearch is to investigate the influences of pitch of blades, inclination angle and flow rate to the turbine output power and turbine eficiency.                The research has been conducted in a 10.1 outside diameter  , 43 cm length  model screw turbine, in which pitch of blades was varied in  2 cm ,3 cm and 4 cm, inclination angle was varied in 10 0 ,150 , 200, 250 , 300, 350 and  45 0 and flow rate was varied in   84 l/min, 95 l/min and 105 l/min.                It is concluded from the research that maximum rotation 240 rpm, maximum power output is 5,558 Watt, maximum eficiency is 44,349 %, and they are reached at 105 l/men flow rate, 20 0  incline angle. and 3 cm pitch blades.  Keywords : screw turbine, low head, power, eficiency, pitch.

scholarly journals Output Power Stability for Wind Turbine by using two Fault Detection Technique and PID – Fuzzy Controller in the Doubly fed Induction Generator

2021 ◽  
Vol 11 (1) ◽  
pp. 37-40
Author(s):  
Ajay Kumar Shukla ◽  
◽  
Anil Kumar Kurchania ◽  
Keyword(s):  
Fault Detection ◽  
Wind Turbine ◽  
Output Power ◽  
Power Output ◽  
Fuzzy Controller ◽  
Detection Technique ◽  
Induction Generator ◽  
Doubly Fed Induction Generator ◽  
Three Phase ◽  
Doubly Fed

The generation of electricity through a wind turbine system is rapidly increasing. Generation of an electricity form a wind turbine is one of the preeminent renewables sources of energy as it is easily available. In many wind farms, the speed of wind is variable due to which achieving stable power output and fault detection is one of the challenges. This objective can be achieved by a doubly fed induction generator (DFIG) along with the use of a fuzzy -PID controller and two fault detection technique in WTs. This Paper shows an investigation of the fault’s detection and improvement in the DFIG model for the constant/stable power output. This model design to show DFIG 9MW (6 x 1.5) along with a 30 km transmission line and the Frequency used for RLC specification is 60 Hz. Asynchronous machine in plant of 1.68 MW, 0.93 power factor, and 2300V line voltage with mechanical power 3 x 103 W. The initial constant wind speed of 15 ms-1 is maintained. Two fault detectors, one phase fault at B25 (25 kV) before the transmission to three-phase two winding transformer. Other phase faults at B120 (120 kV) before the transmission to three phase mutual inductance. The fault actuator in the doubly fed induction generators are reliable and also maintains the safety of wind turbine connected with a grid. PID-Fuzzy Controller is introduced to regulate the speed of the rotor by adjusting pitch which controls speed changes. The result shows due to controlling of pitch angle output level is improved and a good quality factor is achieved. We have introduced a fuzzy controller so the maximum output power can be established to the grid at the trip. In this research work, mathematical modeling of DFIG is presented.

CFD Calculation of Wind Turbines Power Variations in Urban Areas

2012 ◽  
Vol 622-623 ◽  
pp. 1084-1088
Author(s):  
Jafar Bazrafshan ◽  
Payam Sabaeifard ◽  
Farid Khalafi ◽  
Majid Jamil
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Power Output ◽  
Urban Areas ◽  
Stokes Equations ◽  
Horizontal Axis ◽  
Navier Stokes ◽  
Horizontal Axis Wind Turbine ◽  
Navier Stokes Equations ◽  
Cfd Method

Integrating wind turbines in urban areas especially over buildings is a new way of producing electricity which is supported in recent years. Wind turbines sited well above the roof of buildings operate in skewed flow. In this paper, to examine variations in efficiency of wind turbines in this condition, two models of H-Rotor and horizontal axis wind turbine analyzed based on axial momentum theory through computer simulations. Simulations conducted through CFD method and k-ε turbulence model was utilized to analyze flow fluctuations in Navier-Stokes equations. Models show that, for an H-Rotor, the optimal power output in tilted flow can be up to two times the power output of horizontal axis wind turbine (HAWT).

Caffeine supplementation for 4-day, followed by acute ingestion, did not impact triathlete output power after submaximal intensity exercise

2019 ◽  
Vol 18 (3) ◽  
pp. 118
Author(s):  
Anderson Pontes Morales ◽  
Felipe Sampaio-Jorge ◽  
Thiago Barth ◽  
Alessandra Alegre De Matos ◽  
Luiz Felipe Da Cruz Rangel ◽  
...  
Keyword(s):  
Blood Lactate ◽  
Output Power ◽  
Body Mass ◽  
Effect Size ◽  
Power Output ◽  
Anaerobic Power ◽  
Lactate Concentration ◽  
Wingate Test ◽  
Large Effect Size ◽  
Acute Ingestion

Introduction: The aim of this study was to test the hypothesis that caffeine supplementation (6 mg·kg-1 body mass) for 4-days, followed by acute intake, would impact five male triathletes output power after performed submaximal intensity exercise. Methods: This was a randomized, double-blind, placebo-controlled crossover study, placebo (4-day) - placebo (acute) PP, placebo (4-days) -caffeine (acute) PC, and caffeine (4-day) - caffeine (acute) CC. Participants abstained from dietary caffeine sources for 4 days and ingested capsules containing either placebo or caffeine (6 mg.kg-1 body mass day in one absorption). The acute trials the capsules containing placebo or caffeine (6 mg.kg-1 body mass day in one absorption) were ingested 60min before completing exercise in a treadmill for 40min (80% VO2max) and to perform the Wingate test. Results: Blood lactate was determined before, 60min after ingestion, and immediately after the exercise on the treadmill, the Wingate test, and after the recovery (10-min). CC and PC trials did not change the cardiopulmonary variables (P>0.05) and the anaerobic power variables (peak/mean power output and fatigue index) (P>0.05). The PC trial compared with PP promoted improvements in the curve power output in 2 sec by 31.19% (large effect-size d = 1.08; P<0.05) and 3 sec by 20% (large effect-size d = 1.19; P<0.05). A 10min recovery was not sufficient to reduce blood lactate concentration in the PC trial compared with PP (PC, 13.73±2.66 vs. PP, 10.26±1.60 mmol.L-1; P<0.05, respectively) (P<0.05). Conclusion: In conclusion, these results indicate that caffeine supplementation (6 mg·kg-1 body mass) for 4 days, followed by acute ingestion, did not impact the triathletes output power after performed submaximal intensity exercise. Nutritional interventions may help researchers and athletes to adapt strategies for manipulating caffeine use.Key-words: caffeine metabolism, Wingate test, blood lactate, performance.

scholarly journals Geometrical Optimization of a Venturi-Type Microbubble Generator Using CFD Simulation and Experimental Measurements

Designs ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 4
Author(s):  
Dillon Alexander Wilson ◽  
Kul Pun ◽  
Poo Balan Ganesan ◽  
Faik Hamad
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Cfd Simulation ◽  
Air Flow ◽  
Bubble Diameter ◽  
Diameter Ratio ◽  
Experimental Measurements ◽  
Cfd Model ◽  
Flow Rates ◽  
Throat Diameter

Microbubble generators are of considerable importance to a range of scientific fields from use in aquaculture and engineering to medical applications. This is due to the fact the amount of sea life in the water is proportional to the amount of oxygen in it. In this paper, experimental measurements and computational Fluid Dynamics (CFD) simulation are performed for three water flow rates and three with three different air flow rates. The experimental data presented in the paper are used to validate the CFD model. Then, the CFD model is used to study the effect of diverging angle and throat length/throat diameter ratio on the size of the microbubble produced by the Venturi-type microbubble generator. The experimental results showed that increasing water flow rate and reducing the air flow rate produces smaller microbubbles. The prediction from the CFD results indicated that throat length/throat diameter ratio and diffuser divergent angle have a small effect on bubble diameter distribution and average bubble diameter for the range of the throat water velocities used in this study.

scholarly journals Output Power Maximization of DFIG Wind Turbine using Linear MPC Technique

2021 ◽  
Vol 1878 (1) ◽  
pp. 012045
Author(s):  
S M Suboh ◽  
M S Hassan ◽  
N H Baharudin ◽  
K Ananda-Rao ◽  
N B Ahamad ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Output Power ◽  
Power Maximization

Wind Turbine Power output Prediction Using a New Hybrid Neuro-Evolutionary Method

Energy ◽  
2021 ◽  
pp. 120617
Author(s):  
Mehdi Neshat ◽  
Meysam Majidi Nezhad ◽  
Ehsan Abbasnejad ◽  
Seyedali Mirjalili ◽  
Daniele Groppi ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Power Output ◽  
Evolutionary Method

scholarly journals Analytical Modeling of a Doubly Clamped Flexible Piezoelectric Energy Harvester with Axial Excitation and Its Experimental Characterization

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3861
Author(s):  
Jie Mei ◽  
Qiong Fan ◽  
Lijie Li ◽  
Dingfang Chen ◽  
Lin Xu ◽  
...  
Keyword(s):  
Output Power ◽  
Power Output ◽  
Output Voltage ◽  
Energy Harvester ◽  
Load Resistance ◽  
Engineering Practice ◽  
Maximum Output ◽  
Widespread Application ◽  
Piezoelectric Energy ◽  
Axial Excitation

With the rapid development of wearable electronics, novel power solutions are required to adapt to flexible surfaces for widespread applications, thus flexible energy harvesters have been extensively studied for their flexibility and stretchability. However, poor power output and insufficient sensitivity to environmental changes limit its widespread application in engineering practice. A doubly clamped flexible piezoelectric energy harvester (FPEH) with axial excitation is therefore proposed for higher power output in a low-frequency vibration environment. Combining the Euler–Bernoulli beam theory and the D’Alembert principle, the differential dynamic equation of the doubly clamped energy harvester is derived, in which the excitation mode of axial load with pre-deformation is considered. A numerical solution of voltage amplitude and average power is obtained using the Rayleigh–Ritz method. Output power of 22.5 μW at 27.1 Hz, with the optimal load resistance being 1 MΩ, is determined by the frequency sweeping analysis. In order to power electronic devices, the converted alternating electric energy should be rectified into direct current energy. By connecting to the MDA2500 standard rectified electric bridge, a rectified DC output voltage across the 1 MΩ load resistor is characterized to be 2.39 V. For further validation of the mechanical-electrical dynamical model of the doubly clamped flexible piezoelectric energy harvester, its output performances, including both its frequency response and resistance load matching performances, are experimentally characterized. From the experimental results, the maximum output power is 1.38 μW, with a load resistance of 5.7 MΩ at 27 Hz, and the rectified DC output voltage reaches 1.84 V, which shows coincidence with simulation results and is proved to be sufficient for powering LED electronics.

scholarly journals An Optimized Flutter-Driven Triboelectric Nanogenerator with a Low Cut-In Wind Speed

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 366
Author(s):  
Yang Xia ◽  
Yun Tian ◽  
Lanbin Zhang ◽  
Zhihao Ma ◽  
Huliang Dai ◽  
...  
Keyword(s):  
Power Generation ◽  
Wind Speed ◽  
Energy Harvesting ◽  
Wind Energy ◽  
Output Power ◽  
Open Circuit Voltage ◽  
Open Circuit ◽  
Triboelectric Nanogenerator ◽  
Vibration Behavior ◽  
Air Speed

We present an optimized flutter-driven triboelectric nanogenerator (TENG) for wind energy harvesting. The vibration and power generation characteristics of this TENG are investigated in detail, and a low cut-in wind speed of 3.4 m/s is achieved. It is found that the air speed, the thickness and length of the membrane, and the distance between the electrode plates mainly determine the PTFE membrane’s vibration behavior and the performance of TENG. With the optimized value of the thickness and length of the membrane and the distance of the electrode plates, the peak open-circuit voltage and output power of TENG reach 297 V and 0.46 mW at a wind speed of 10 m/s. The energy generated by TENG can directly light up dozens of LEDs and keep a digital watch running continuously by charging a capacitor of 100 μF at a wind speed of 8 m/s.

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