International Journal of Engineering Advanced Research (IJEAR) eISSN: 2710-7167 [Vol. 3 No. 1 March 2021]
Journal website: http://myjms.mohe.gov.my/index.php/ijear
A MINI REVIEW OF POWER GENERATION FROM EXHAUST AIR ENERGY RECOVERY WIND TURBINE
Ainaa Maya Munira Ismail1*, Zurriati Mohd Ali2, Kamariah Md Isa3, Mohammad Abdullah4, Arbanah Muhammad5 and Fazila Mohd Zawawi6
1 2 3 Faculty of Mechanical Engineering, University of Technology MARA, Johor Branch, Pasir Gudang Campus,
Bandar Seri Alam, MALAYSIA
4 5 Faculty of Chemical Engineering, University of Technology MARA, Johor Branch, Pasir Gudang Campus, Bandar Seri Alam, MALAYSIA
6 School of Mechanical Engineering, Faculty of Engineering, Universiti of Technology Malaysia, Skudai, MALAYSIA
*Corresponding author: [email protected]
Article Information:
Article history:
Received date : 6 March 2021 Revised date : 30 March 2021 Accepted date : 31 March 2021 Published date : 31 March 2021 To cite this document:
Ismail, A., Mohd Ali, Z., Md Isa, K., Abdullah, M., Muhammad, A., & Mohd Zawawi, F. (2021). A MINI REVIEW OF POWER GENERATION FROM EXHAUST AIR ENERGY RECOVERY WIND TURBINE. International Journal Of Engineering Advanced Research, 3(1), 83-93.
Abstract: In recent times, global lockdown from Covid-19 resulted a significant impact on various sector across the board, especially energy consumption. During the pandemic apparently when it comes to electricity generation, lockdowns have fuelled the rise of low-carbon energy. The world is unceasingly trying to resolve the crisis by exploring the economical renewable energy resources and one of them is wind energy where this sustainable energy system is highly demanded for a greener future. Researchers have performed numerous studies of wind energy derived from wind turbines on various potential sites, but the majority used natural sources as wind streams. As a result, an innovative concept for harvesting renewable energy from human-made wind resources using a micro wind turbine system for power generation were presented in some studies. The output of power generation via Exhaust Air Energy Recovery Wind Turbine was highlighted in this mini review. Thus, the new approach is reviewed to obtain a better understanding on its potentiality.
Keywords: Low-carbon Energy, Power Generation, Exhaust Air Energy Recovery Wind Turbine.
1. Introduction
A disease outbreak known as Covid-19 has recently halted growth and development. There are many fatalities worldwide, along with the huge public health, business and workplace crises caused by this epidemic. Nonetheless, the International Energy Agency (IEA) predicts that, while the crisis triggered an unprecedented drop in electricity demand since the great depression, renewables will continue to grow because energy is the economy's driving force. Since fossil fuel reserves are rapidly depleting and no new reserves have been found, thus the environmental effect of their consumption (Yap et al., 2014) signifies renewable energy remains the world's most insistent issue today. Wind, sunshine, rain, tides, waves, and geothermal heat are all examples of renewable energy. Among them, wind energy has been recognized as the most promising of renewable alternative, therefore there is a policy formulated to ensure that the role of wind power in energy resources is expanding (E.A.D. Kumara K.G.R.M. Jayathilake, 2017), hence it is one of the most attractive solutions for safe and clean renewable energy sources(Chauhan & Singh, 2014). Wind energy can be generated from the wind by using a rotary device known as a wind turbine. The wind turbine transforms kinetic energy into mechanical energy, which is then converted into electrical energy (Kumara et al., 2017). Wind turbines are classified by the horizontal or vertical orientation of the rotor axis in relation to the wind direction (Simatupang & Sulistiohadi, 2016).
However, there are yet many things to be tackled regarding wind turbine restrictions. The conventional wind turbine is unsuitable for low-speed regions and is also expensive to produce.
Nevertheless, wind energy technology developed rapidly over the decades; a revolutionary concept to harvest wind energy from non-natural wind resources may be one of the solutions for generating electricity. The unnatural sources available from man-made operations such as cooling tower system, exhaust fan and ventilator. The reliable, high-speed and inevitable produced by this system is beneficials to generate electricity (Fazlizan et al., 2015). Therefore, the intentions this paper is to accentuate the power generation capacity of an Exhaust Air Energy Recovery Wind Turbine.
This type of wind turbine is typically designed in small configurations to accommodate the size of the exhaust air recovery system. Many researchers have suggested ideas for wind energy systems that could be deployed in urban environments for local energy generation, despite the fact that bringing wind energy technology into urban areas is a more difficult proposition due to the limited space available and the wind turbine's adaptation to existing facilities. From previous literature, it has been efficient in developing commercially available small wind turbines, demonstrating that small-scale wind energy is cost-effective(Tummala et al., 2016). Furthermore, small wind turbines are mostly used for domestic uses, rural areas, or small production needs (Shivsharan et al., 2020).
In fact, small wind turbines are gaining in popularity with a rising number of private homes and businesses now use small wind turbines especially in Europe Country (Paulides et al., 2013). Even though the total performance of the presented micro turbines is restricted, it is suggests that these turbines may provide an alternative source of energy for use in city environment (Bui & Melis, 2013).
2. Wind Energy
Wind is a clean, free, and easily accessible renewable energy source. Wind energy can be used to help a lower-energy fuel perform better. Hence, on a global scale, wind power deployment is viewed as an established technology(Tong, 2009). Hydrogen and ammonia are two possibilities.
Wind-generated electricity can be used to electrolyze water to create hydrogen. Electricity generated by wind can be used to generate hydrogen by electrolysis of water. The fundamental relationship is as follows:
𝐻2𝑂 → 𝐻2+ 1
2𝑂2∆𝐻 = 286𝑘𝑗/𝑚𝑜𝑙 𝐻2𝑂 where ∆𝐻 = 𝑐ℎ𝑎𝑛𝑔𝑒 𝑒𝑛𝑡ℎ𝑎𝑙𝑝𝑦, mol=gram molecular weight
The hydrogen produced is normally stored in tanks as a compressed gas, but it can also be stored as a liquid. Hydrogen can be used as a fuel or it may be converted back to electricity. Then, ammonia is another possible fuel that could be produced by using the wind as an energy source.
The process involves the conversion of hydrogen produced as the following reaction:
3𝐻2+ 𝑁2 → 2𝑁𝐻3
Ammonia has certain properties that make it more convenient than hydrogen, but it is poisonous when released into the air, and it readily absorbs into water, so this property must be considered when designing ammonia handling equipment. Furthermore, the atomic combination of hydrogen (H) into helium (He) in its core produces wind vitality, which is a transformed type of sunlight- based vitality. The 𝐻 → 𝐻𝑒 dissolving phase sends out waves of heat and electromagnetic radiation from the sun to space in all directions. By developing use of wind energy would diminish the need for non-renewable sources, which may be sooner or later used for all of these services.
Additionally, the cost per kWh of solar vitality is much lower. Blowing plays a major role in supplying global vitality in the 21st century (Kumar et al., 2018). Thus, wind speed, air density, and the swept area of the turbine are three major factors that influence wind energy measurement.
3. Wind Turbine Configurations
In 1890, the first windmill was commissioned to produce electricity in rural America. Large wind turbines are now competing with utilities to provide renewable power at a reasonable price(Islam et al., 2018). Wind energy converters can be categorized according to their aerodynamic features and design (Alnoman, 2013). Horizontal Axis Wind Turbines (HAWT) and Vertical Wind Turbines (VAWT) are the two primarily types of wind turbines based on their orientation. HAWT is mostly built with three or two blades, where the wind speed is relatively low and the power coefficient is higher, resulting in higher system efficiency and energy yield (Hyams, 2012). On the other hand, by being closer to the ground with ease of maintenance and can be installed on chimneys or similar tall structures, VAWT is more practical in residential and it do not require as much wind to generate power(Müller et al., 2017). The illustration of HAWT and VAWT are shows in Figure 1.
Figure 1: Two main types of wind turbines(E.A.D. Kumara K.G.R.M. Jayathilake, 2017)
3.1 Blade Element Momentum (BEM)
Blade Element Momentum (BEM) Theory was originally introduced by H. Glauert in 1926, is a combination concepts Blade Element Theory with Momentum Theory (Carriveau, 2011) to reduce some of the difficulties in assessing the induced velocity of the rotor. The Blade Element Theory is relatively a simple method for predicting propeller efficiency (as well as fans or windmills), while Momentum Theory is a theory that describes a mathematical model of the ideal actuator disc, such as a propeller or a helicopter. Therefore, BEM Theory is used to estimate turbine efficiency or as a design aid.
3.2 Aerodynamics of Wind Turbine
The topology is used to design any kind of turbine's aerodynamics. An Aerodynamic performance such as power, torque and thrust based on BEM theory, combined with blades and tower structural dynamic model(Wang, 2012).It is therefore clear that aerodynamics can be determined by two components, Lift and Drag Force; formed as an effect of uneven pressure on the upper and lower surfaces of the airfoil. Lift is defined as the force produced perpendicular to the direction of travel for an object moving through a fluid, while Drag is the force produced in a direction that is parallel to but not the same as the travel direction. The incoming wind exerts a Lift and Drag force on the airfoil, hence both forces are highly dependent on the Angle of Attack (AOA) as illustrated in Figure 2. As a result, increasing the angle of attack will result in increased lift(Li et al., 2010) as well drag. An optimised AOA that would result in a large lift with a small drag is therefore desirable(Tumewu et al., 2017).
Figure 2: Lift and drag force of wind turbine airfoil (Tumewu et al., 2017)
Thus, the Lift Coefficient (CL) and Drag Coefficient (CD) for a given airfoil can be calculated using theoretical or empirical test results and it is defined as:
𝐶𝐿 = 𝐹𝐿 0.5 𝜌𝑉2𝐶 𝐶𝐷 = 𝐹𝐷
0.5 𝜌𝑉2𝐶
where Air Density, ρ (kg/m3), Airfoil Length denoted by the chord, C (m), Air Velocity, V (m/s), Lift Force, FL(N/m), Drag Force, FD(N/m).
3.3 Tip Speed Ratio (TSR)
In wind turbine design, the Tip Speed Ratio (TSR) is important and its defined as the ratio of wind speed to the speed of the wind turbine blade tips. TSR is defined as follows:
𝑇𝑆𝑅 =Ω𝑅
𝑉
where, Rotational speed, Ω (radians/sec),Rotor radius, R (m), Wind “Free Stream” Velocity, V (m/s).
3.4 Wind Power Generation
According to Betz's law, the maximum possible extraction of wind power by an ideal wind turbine is only 59.3% of the total kinetic energy of the air flowing through the turbine (Medeiros & Dias, 2013). Power coefficient (CP) is a common measurement in the wind energy industry. Cp is the ratio of a wind turbine's real electric power output to the total wind power flowing into the turbine blades at a given wind speed and can be calculate by using following formula:
𝐶𝑝 = 𝑃 0.5𝜌𝐴𝑉3
where Power, P, Air Density, ρ (kg/m3), Rotor Area, A, Overall Rotor Diameter, D, and Wind Velocity, V (m/s).
4. Potentiality of Power Generation from Exhaust Air Energy Recovery Wind Turbine The conventional wind turbines require strong winds and fluctuating weather to function, which makes them especially vulnerable to fluctuations in environmental conditions. Therefore, waste energy recovery has a powerful potential to help address the global energy crisis in addition to other renewable energy alternatives. Numerous investigations have been conducted and prove the potentiality of power generation by exhaust air energy recovery wind turbine. For harvesting wind energy, cooling towers are a viable choice. They come in a variety of sizes (models) and are built and manufactured in a variety of ways(Stanford III, 2012). Based on (Fazlizan et al., 2015), the optimum position of the VAWT is at the higher wind speed corresponds to the positive torque area of the turbine rotation. The turbine system was able to recover wasted kinetic energy while also reducing fan power consumption by 4.5% and raising the intake air flow rate of the cooling tower by 11% by properly balancing the VAWT configurations (blade number, airfoil form, operating tip-speed ratio, etc.) and the exhaust air profile. The VAWT had a free-running rotational speed of 479 rpm, a power coefficient of 10.6%, and a TSR of 1.88. The double multiple stream tube theory was used to describe the VAWT behaviour in a non-uniform wind stream. The maximum Cp was 0.03 at a TSR of 0.98 and a wind speed of 8.5 m/s. The investigation carried out by(Wen Tong Chong et al., 2013) stated that from laboratory and field test reports, there is no major difference in the current consumption of the fan motor with the construction of wind turbine. The enclosure's integration has resulted in a 30.4% increase in the rotational speed of the turbine. The electricity generated by this device can be fed into the power grid. On all test settings, the motor current consumption remains at 0.85 Ampere. Meanwhile, the VAWTs' output when combined with an enclosure has improved, with the turbine rotational speed increased from 463.72 to 500.98 rpm.
During field testing, the discharged airflow was decreased by 1.73%, indicating minimal blockage from the engineered system. When exposed to this discharged air speed, the VAWT is required to perform to its rated power. There was also no major difference in motor power consumption, which was held between 7.0 and 7.1 kW. Next, regarding to (Chew et al., 2011) wind turbine was spinning at 115 rpm after it was mounted above the cooling tower's outlet (when it reached constant rpm). The enclosure-enclosed wind turbine, on the other hand, a rotational speed recorded of 150 rpm. The findings show that the enclosure configuration effectively raises the wind turbine's speed by 30.4%. The outlet air speed of the cooling tower with and without wind turbine recorded in (Wen Tong Chong et al., 2012) 10.65m/s and 10.67m/s respectively. The rotational speed of turbine is 881 rpm and No measurable difference was observed on the power consumption which was recorded between 7.0 to 7.1 kW for both cases. Thus, for 3000 units of cooling tower (2 m outlet diameter powered by a 7.5 kW fan motor and operated for 16 hours/day), 13% of the energy to power the fan motor is expected to be recovered from this system which equals 17.5 GWh/year(Fazlizan et al., 2015) (Wen Tong Chong et al., 2013) (Chew et al., 2011) (Wen Tong Chong et al., 2012). According to (Poh et al., 2014), the numerical results by utilized Computational Fluid Dynamic (CFD) package indicated that the maximum wind speed was more than 9 m/s at a radius of about 200 mm, while the lowest wind speed was about 2 m/s near the outer radius. The measurements were taken at 50 mm from the exhaust air outlet. As a result, the strongest torque area of VAWT should be located in the area with the highest wind speed, with the addition of diffuser and guide-vanes at optimised angles (from 0.029 to 0.036), the average torque coefficient of the system increased by 24.3% as illustrated in Figure 3.
Figure 3: Torque coefficient for the system without diffuser and guide-vanes, and the system with diffuser and guide-vanes at optimized angles (Poh et al., 2014)
The research done by (W. T. Chong et al., 2014) revealed that by installing VAWTs at the correct height above the cooling tower doesn't impair the model's efficiency. The VAWTs had a high rotational speed (>400 rpm) and TSR of 1.28 to 1.29, making them ideal for electricity generation.
The enclosure's incorporation resulted in many further enhancements around the board. The enclosure increased the rotational speed of the VAWT by 7% on average, while cutting response times by 41%. The cooling tower model's intake air speed has been increased, while its power consumption has been reduced. Then, by following the investigation performed by (Sathiya Moorthy et al., 2016) describe that the nozzle, which is located between the exhaust fan and the wind turbine, increases the system's power output and reliability. The system's theoretical maximum power produced without a nozzle is around 6.5 W, while the system's theoretical maximum power generated with a nozzle is around 9.5 W. The Energy Recovery System (ERS) saves 95W of energy per day, assuming a working time of 10 hours a day as shown in Figure 4.
The system's overall performance has increased by 6%.
Figure 4: Power vs Overall Efficiency (W. T. Chong et al., 2014)
Furthermore, CFD and ANSYS system was used in (Tabatabaeikia et al., 2016) to simulate the working theory. The results showed that the addition of diffusers and then guide valves increased the total power output of the wind turbine by about 5% and 34%, respectively, contrasted to the use of VAWT alone. The optimum angle for diffusers was 7° while for guide valves A and B, it was 70° and 60°, respectively. The simulation outcome closely matches the experimental values.
Since the parametric analysis is conducted in TSR 2.2, Figure 5 shows that the simulation values near TSR 2.2 are comparatively similar to the experimental values than the values in other TSR.
The range of varying Reynolds numbers in this analysis, however, is not very broad. In contrast to some existing papers, the present study's variations are within a reasonable range. About 13.3 %of the discharged energy is expected to be recovered from the cooling tower with a 7.5 kW rated fan engine. Approximately 7.3 MWh is estimated to be recovered for a year of operation of the cooling tower with this system. Economic analysis shows that the system's capital, replacement components as well as operating and maintenance costs are covered over the lifetime of the system.
The net present (NPV) for this project is 25,347 Malaysian Ringgit (RM) for the 20-year period.
Figure 5: Power coefficients obtained by computational fluid dynamics (CFD) simulation and experimental result (Tabatabaeikia et al., 2016)
In additional, research by (W. T. Chong et al., 2013) revealed the omni-direction-guide-vane (ODGV) that surrounds VAWT help to improve wind turbine performance. At a wind speed of 6 m/s and under free-running conditions (only rotor inertia and bearing friction were applied), the ODGV helps to increase rotor rotational speed by 182%. With an extra load application at the same wind speed (6 m/s), the power output of the wind turbine was increased by 3.48 times at its peak torque with the help of the ODGV. The working concept of the ODGV is to minimise the negative torque zone of the VAWT lift type and to reduce turbulence and rotational speed fluctuations. It was verified by re-simulating the data of the single-bladed torque coefficient (NACA 0015 airfoil) VAWT published by the Sandia National Laboratories. From the simulation results, with the presence of the ODGV, it was shown that the torque output of the NACA 0015 airfoil, single blade VAWT, increased by 58% and 39% at TSR of 2.5 and 5.1, respectively. As a result, the negative torque zone has been minimised so that the positive torque that provides higher power can be achieved.
5. Conclusion
Wind Turbine Performances have been extensively studied for decades, but very few studies have been conducted on Exhaust Air Energy Recovery Wind Turbine. In the papers, the performance improvement of a small scale/building integrated of wind turbine utilized air cooling systems a source of exhaust air energy recovery is discussed. Most of results prove that there is increment performance exhaust air energy recovery wind turbine, especially with enclosure at enclosed area.
By turning waste energy into usable energy like electricity, this energy recovery system has a high market potential and a fast payback period as there are numerous global exhaust air systems. It can be used as an additional power for building lighting or to be fed into the electricity grid for energy demand in urban buildings. It was concluded from previous literatures that this invention is not only capable of recovering the energy, but also does not have any significant negative impact on the performance of the cooling tower if it is installed in the correct position.
6. Acknowledgement
The authors would like to thank and gratefully acknowledge for the financial support by Universiti Teknologi MARA Johor under grant Bestari 600-UiTMCJ (PJIA. 5/2).
References
Alnoman, A. A. (2013). A Review on Wind Turbines Proposed for the City of Erbil – Iraq. Open Access-Renewable Energy, 3–7.
Bui, D. M., & Melis, W. J. C. (2013). Micro Wind Turbines for Energy Gathering in Build Up Areas. 2(2), 105–114.
Carriveau, R. (2011). Fundamental and Advance Topic in Wind Power (Teodora Smiljanic (ed.);
1st ed.). Intech Open Access Publisher.
Chauhan, S., & Singh, R. (2014). Design of Domestic Helix Vertical Axis Wind Turbine to Extract Energy from Exhaust Fans. 5(12), 23–29. www.iiste.org
Chew, P. S., Abdullah, A. F., Sean, O. C., & Ching, T. C. (2011). Exhaust Air and Wind Energy Recovery System for Clean Energy Generation. 2011 International Conference on Environment and Industrial Innovation (ICEII 2011), 12, 45–49.
Chong, W. T., Fazlizan, A., Poh, S. C., Pan, K. C., Hew, W. P., & Hsiao, F. B. (2013). The design, simulation and testing of an urban vertical axis wind turbine with the omni-direction-guide- vane. Applied Energy, 112, 601–609. https://doi.org/10.1016/j.apenergy.2012.12.064
Chong, W. T., Yip, S. Y., Fazlizan, A., Poh, S. C., Hew, W. P., Tan, E. P., & Lim, T. S. (2014).
Design of an exhaust air energy recovery wind turbine generator for energy conservation in
commercial buildings. Renewable Energy, 67, 252–256.
https://doi.org/10.1016/j.renene.2013.11.028
Chong, Wen Tong, Fazlizan, A., Poh, S. C., Yip, S. Y., & Hew, W. P. (2012). The design and testing of an exhaust air energy recovery wind turbine generator. World Renewable Energy Forum, WREF 2012, Including World Renewable Energy Congress XII and Colorado Renewable Energy Society (CRES) Annual Conferen, 4, 2721–2727.
Chong, Wen Tong, Poh, S. C., Fazlizan, A., Yip, S. Y., Koay, M. H., & Hew, W. P. (2013). Exhaust air energy recovery system for electrical power generation in future green cities. International Journal of Precision Engineering and Manufacturing, 14(6), 1029–1035.
https://doi.org/10.1007/s12541-013-0138-3
E.A.D. Kumara K.G.R.M. Jayathilake, N. K. H. (2017). Review Paper- Overview of the Vertical Axis Wind Turbines. International Journal of Scientific Research and Innovative Technology, 4(September), 56–67.
Fazlizan, A., Chong, W. T., Yip, S. Y., Hew, W. P., & Poh, S. C. (2015). Design and experimental analysis of an exhaust air energy recovery wind turbine generator. Energies, 8(7), 6566–6584.
https://doi.org/10.3390/en8076566
Hyams, M. A. (2012). Wind energy in the built environment. Metropolitan Sustainability:
Understanding and Improving the Urban Environment, 457–499.
https://doi.org/10.1533/9780857096463.3.457
Islam, S. M., Nayar, C. V., Abu-Siada, A., & Hasan, M. M. (2018). Power Electronics for Renewable Energy Sources. In Power Electronics Handbook (4th ed.). Elsevier Inc.
https://doi.org/10.1016/b978-0-12-811407-0.00027-1
Kumar, A., Khan, M. Z. U., & Pandey, B. (2018). Wind Energy: A Review Paper. Gyancity Journal of Engineering and Technology, 4(2), 29–37. https://doi.org/10.21058/gjet.2018.42004 Kumara, E. A. D., Hettiarachchi, N. K., & Jayathilake, K. G. R. M. (2017). Review Paper:
Overview of the Vertical Axis Wind Turbines. 4(8), 56–67.
Li, J. Y., Li, R., Gao, Y., & Huang, J. (2010). Shape Optimization of Wind Turbine Blades.
Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, 224(6), 827–838. https://doi.org/10.1243/09576509JPE888
Medeiros, E. E., & Dias, A. M. S. (2013). Experimental and Numerical Analysis of Vickers.
17(November), 9–18.
Müller, G., Chavushoglu, M., Kerri, M., & Tsuzaki, T. (2017). A resistance type vertical axis wind turbine for building integration. Renewable Energy, 111(May), 803–814.
https://doi.org/10.1016/j.renene.2017.05.017
Paulides, J. J. H., Encica, L., Jansen, J. W., & Lomonova, E. A. (2013). Small-scale Urban Venturi Wind Turbine : Direct-Drive Generator. 1368–1373.
Poh, S. C., Sim, S. Y., Chong, W. T., Fazlizan, A., Yip, S. Y., Hew, W. P., Omar, W. Z. W., &
Zain, Z. M. (2014). Computational fluid dynamics simulation of the effect of guide-vane angles on the performance of the exhaust air energy recovery turbine generator. Energy Procedia, 61, 1286–1289. https://doi.org/10.1016/j.egypro.2014.11.1082
Sathiya Moorthy, K., Sundar Singh Sivam, S. P., Shivashankar, P., & Adithya, S. (2016). Wind energy recovery from a cooling tower with the help of a wind turbine generator. Indian Journal of Science and Technology, 9(37). https://doi.org/10.17485/ijst/2016/v9i37/94792
Shivsharan, B. A., Magade, P. B., Chavan, S., & Magade, S. (2020). A Review Paper on Vehicle Mounted Wind Turbine. 15(7), 740–747.
Simatupang, J. W., & Sulistiohadi, K. (2016). Portable Wind Turbine for Energy Recharging Device Applications. 1(1), 19–24.
Stanford III, H. W. (2012). - Cooling Tower Fundamentals. HVAC Water Chillers and Cooling Towers, 152–165. https://doi.org/10.1201/b11510-13
Tabatabaeikia, S., Nik-Ghazali, N. N. Bin, Chong, W. T., Shahizare, B., Fazlizan, A., Esmaeilzadeh, A., & Izadyar, N. (2016). A comparative computational fluid dynamics studyv on an innovative exhaust air energy recovery wind turbine generator. Energies, 9(5).
https://doi.org/10.3390/en9050346
Tong, W. (2009). Fundamentals of wind energy. WIT Transactions on State of the Art in Science and Engineering, Vol 44, ISSN 1755-8336 (on-Line) Doi 10.2495/978-1-84564-205-1/01, 34, 1755–8336. https://doi.org/10.2495/978-1-84564
Tumewu, Y., Crescenzo, P., & Sivaselvan, M. (2017). Numerical Simulation of the Influence of Platform Pitch Motion on Power Generation Steadiness in Floating Offshore Wind Turbines.
International Journal of Environmental Science & Sustainable Development., 2(1), 92.
https://doi.org/10.21625/essd.v1i2.39
Tummala, A., Kishore, R., Kumar, D., Indraja, V., & Krishna, V. H. (2016). A review on small scale wind turbines. Renewable and Sustainable Energy Reviews, 56, 1351–1371.
https://doi.org/10.1016/j.rser.2015.12.027
Wang, T. (2012). A brief review on wind turbine aerodynamics. Theoretical and Applied Mechanics Letters, 2(6), 62001. https://doi.org/10.1063/2.1206201
Yap, H. T., Ong, Z. C., Chong, W. T., Kong, K. K., Khoo, S. Y., Ismail, Z., & Rahman, A. G. A.
(2014). Design optimisation of shroud-augmented dual-rotor exhaust air energy recovery wind turbine generator using hybrid non-destructive evaluation approach. Energy Procedia, 61, 1266–1269. https://doi.org/10.1016/j.egypro.2014.11.1077
