Large-eddy simulation of airborne wind energy farms

The future utility-scale deployment of airborne wind energy technologies requires the development of large-scale multi-megawatt systems. This study aims at quantifying the interaction between the atmospheric boundary layer (ABL) and large-scale airborne wind energy systems operating in a farm. To that end, we present a virtual flight simulator combining large-eddy simulations to simulate turbulent flow conditions and optimal control techniques for flight-path generation and tracking. The two-way coupling between flow and system dynamics is achieved by implementing an actuator sector method that we pair to a model predictive controller. In this study, we consider ground-based power generation pumping-mode AWE systems (lift-mode AWES) and on-board power generation AWE systems (drag-mode AWES). For the lift-mode AWES, we additionally investigate different reel-out strategies to reduce the interaction between the tethered wing and its own wake. Further, we investigate AWE parks consisting of 25 systems organized in 5 rows of 5 systems. For both lift- and drag-mode archetypes, we consider a moderate park layout with a power density of 10 MW km−2 achieved at a rated wind speed of 12 m s−1. For the drag-mode AWES, an additional park with denser layout and power density of 28 MW km−2 is also considered. The model predictive controller achieves very satisfactory flight-path tracking despite the AWE systems operating in fully waked, turbulent flow conditions. Furthermore, we observe significant wake effects for the utility-scale AWE systems considered in the study. Wake-induced performance losses increase gradually through the downstream rows of systems and reach in the last row of the parks up to 17 % for the lift-mode AWE park and up to 25 % and 45 % for the moderate and dense drag-mode AWE parks, respectively. For an operation period of 60 minutes at a below-rated reference wind speed of 10 m s−1, the lift-mode AWE park generates about 84.4 MW of power, corresponding to 82.5 % of the power yield expected when AWE systems operate ideally and interaction with the ABL is negligible. For the drag-mode AWE parks, the moderate and dense layouts generate about 86.0 MW and 72.9 MW of power, respectively, corresponding to 89.2 % and 75.6 % of the ideal power yield.

Perancangan dan Implementasi Tracking Solar Cell System dengan Menggunakan Overload Protection

Solar cell tracking system is a system that uses the latest technology with combining solar tracking, the intensity of sunlight absorbed by solar cells can be optimized automatically. The purpose of this study is to make the Arduino-based solar monitoring system and load protection tool. The device is also equipped with an LDR sensor that detects the presence of sunlight, sends data from the LDR to Arduino and delivers signals to linear actuators. When the charge supplied by the battery exceeds the capacity of the battery, the INA219 sensor detects overload and a signal sent to Arduino asking for a relay to release the load. The results showed that tracking solar cell systems were successful in improving the efficiency of solar cells with an average power yield of 0.87 ampere of 12.62 watts from before without tracking the average obtained 0.62 ampere 8.83 atts. The performance of the protection system indicates that the load is cut off when the charging current exceeds the specified limit of 2.6 ampere.

Design and Development of Light Weight Stirling Engine by using Compressor

From the nineteenth century, the mechanical transformation needs an incredible nuclear power creation. The pre-owned advances have a few specialized issues making hurt people and harming materials. There are numerous ways by which altering existing methods will assist with diminishing the uses. The work proposes the best approach to assemble and use the minimal expense Stirling motor for the efficient power energy application. A protected outside burning motor was the creation proposed by Robert Stirling to save human existence and materials. This motor is imagined for working with various temperatures without start inside by squander heat recuperation. It is worked by cyclic pressure and extension measure. The plan interaction includes the plan of chambers, heat expansion, dismissal, proficiency, power yield and some more. This motor is agreeable for individuals since it is very, less loud and minimized in size and alpha motor has more noteworthy proportion contrasted with different sorts. It is elective fuel hotspot for other fuel. This is efficient power energy application. This present’s development and execution trial of an alpha-type Stirling motor.

PENGARUH VARIASI PANJANG PEGAS KOPLING TERHADAP PERFORMA DAN KONSUMSI BAHAN BAKAR PADA HONDA TIGER 200 CC

Good acceleration and performance are influenced by the degree of flexibility of the clutch springs. The objective that underlies the implementation of this study is to determine the effect of replacing the clutch spring with different length variations. In this study, the data taken is the torque, power and fuel consumption of each type of clutch spring. In this test, two types of clutch springs were used, namely the standard clutch spring and the TDR type coupling spring which were varied in length (38.31mm), (40.93mm) with the addition of 2mm (42.93mm), (40.31mm) rings. also cutting thread 2mm (38.93mm), (36.31mm). Tests were carried out using a dynotest tool with an engine speed of 4000 rpm to 9000 rpm transmission position six. In the TDR clutch spring (42.93mm) there is an increase in torque of 7.42% with a torque yield of 16.20 Nm at 6000 rpm and an increase in power of 6.61% with a power yield of 14.5 HP at 7000 rpm. For fuel consumption TDR coupling spring at ideal rotation (low-medium), an increase of 9.68%. The decrease in fuel consumption only occurred at the top / high speed of 6.32%. For the test results pertalite ethanol fuel, there is a decrease in fuel consumption compared to pertalite fuel for all RPM variables

Blades Optimization for Maximum Power Output of Vertical Axis Wind Turbine

Wind power is a significant and urging sustainable power source asset to petroleum derivatives. Wind machines, for example, H-Darrieus vertical pivot wind turbines (VAWTs) have increased much notoriety in research network throughout the most recent couple of decades because of their applications at destinations having moderately low wind speed. Be that as it may, it is noticed that such wind turbines have low effectiveness. The point of this examination is to plan rotor cutting edges which could create most extreme power yield and execution. Different plan factors, for instance, harmony length, pitch edge, rotor distance across, cutting edge length and pitch point are explored to upgrade the presentation of VAWT. Rotor cutting edges are manufactured using the NACA-0030 structure and tried in wind burrow office and contrast its outcomes and DSM 523 profile. Numerical simulations are performed to get best geometry and stream conduct for achieving greatest power. It is seen that for higher tip-speed-proportion (TSR), shorter harmony length and bigger distance across the rotor (i.e., lower robustness) yields higher effectiveness in NACA 0030. Nevertheless, for lower TSR, the more drawn out agreement length and slighter distance across rotor (i.e., higher strength) gives better implementation. The pitch point is - 2° for TSR = 3 and - 3° for TSR = 2.5. The most extreme power yield of the wind turbine is acquired for the sharp edge profile NACA 0030. Besides, instantaneous control coefficient, power coefficient (CP) is the greatest reason for azimuthal edge of 245° and least esteem for 180°.

Optimal tuning of engineering wake models through lidar measurements

Engineering wake models provide the invaluable advantage to predict wind turbine wakes, power capture, and, in turn, annual energy production for an entire wind farm with very low computational costs compared to higher-fidelity numerical tools. However, wake and power predictions obtained with engineering wake models can be insufficiently accurate for wind farm optimization problems due to the ad hoc tuning of the model parameters, which are typically strongly dependent on the characteristics of the site and power plant under investigation. In this paper, lidar measurements collected for individual turbine wakes evolving over a flat terrain are leveraged to perform optimal tuning of the parameters of four widely used engineering wake models. The average wake velocity fields, used as a reference for the optimization problem, are obtained through a cluster analysis of lidar measurements performed under a broad range of turbine operative conditions, namely rotor thrust coefficients, and incoming wind characteristics, namely turbulence intensity at hub height. The sensitivity analysis of the optimally tuned model parameters and the respective physical interpretation are presented. The performance of the optimally tuned engineering wake models is discussed, while the results suggest that the optimally tuned Bastankhah and Ainslie wake models provide very good predictions of wind turbine wakes. Specifically, the Bastankhah wake model should be tuned only for the far-wake region, namely where the wake velocity field can be well approximated with a Gaussian profile in the radial direction. In contrast, the Ainslie model provides the advantage of using as input an arbitrary near-wake velocity profile, which can be obtained through other wake models, higher-fidelity tools, or experimental data. The good prediction capabilities of the Ainslie model indicate that the mixing-length model is a simple yet efficient turbulence closure to capture effects of incoming wind and wake-generated turbulence on the wake downstream evolution and predictions of turbine power yield.

The Impacts of Tracking System Inaccuracy on CPV Module Power

The accuracy and reliability of solar tracking greatly impacts the performance of concentrator photovoltaic modules (CPV). Thus, it is of utmost significance to know how deviations in tracking influence CPV module power. In this work, the positioning characteristics of CPV modules compared to the focus points were investigated. The performance of CPV modules mounted on a dual-axis tracking system was analysed as a function of their orientation and inclination. The actual experiment was carried out with CPV cells of 3 mm in diameter. By using a dual tracking system under real weather conditions, the module’s position was gradually modified until the inclination differed by 5° relative to the optimal position of the focus point of the CPV module. The difference in inclination was established by the perfect perpendicularity to the Sun’s rays. The results obtained specifically for CPV technology help determine the level of accuracy that solar tracking photovoltaic systems are required to have to keep the loss in power yield under a certain level. Moreover, this power yield loss also demonstrated that the performance insensitivity thresholds of the CPV modules did not depend on the directions of the alterations in azimuthal alignment. The novelty of the research lies in the fact that earlier, no information had been found regarding the tracking insensitivity point in CPV technologies. A further analysis was carried out to compare the yield of CPV to other, conventional photovoltaic technologies under real Central European climate conditions. It was shown that CPV needs a sun tracking accuracy of at least 0.5° in order to surpass the yield of other PV technologies. Besides providing an insight into the tracking error values of solar tracking sensors, it is believed that the results might facilitate the planning of solar tracking sensor investments as well as the economic calculations related to 3 mm cell diameter CPV system investments.