The present work uses the blade element momentum theory method for evaluating the performance of horizontal axis wind turbine. The wind turbine performances are described in term of the thrust coefficient CT, torque coefficient CQ and the power coefficient CP. The blade element momentum theory (BEMT) represents the wind turbine performance prediction method as result of combining two methods, namely the blade element theory (BET) and the momentum theory (MT). Both theories are able to formulate the axial forces and torques which work on the blade. Equating axial force and torque formulated by BET is equal axial force and torque by MT, makes one allows the axial induction factor and the angular induction factor a^’, the unknown quantities, can be defined and furthermore the wind turbine performances can be evaluated. The BEMT method used here is the combination of BEMT. The implementation this method as the tool for predicting the wind turbine performances are work well. However, for wind turbine configuration need a little adjustment, especially in setting the hub radius rh where the blade element momentum theory starts to make calculation from the inner blade to the tip. The high pitch angle and a relatively a large chord length at rh, make the BEMT fail to converge. In addition to the present work found that the three wind turbine performance coefficients are formulated by using the momentum theory is less accurate compared with BET formulation.

The purpose of this study is to experimentally investigate the engine performance and pollutant emission of a commercial SI engine using ethanol–gasoline blended fuels with various blended rates (0%, 5%, 10%, 20%, and 30%). Fuel properties of ethanol–gasoline blended fuels were first examined by the standard ASTM methods. Results showed that by increasing the ethanol content, the heating value of the blended fuels is decreased, while the octane number of the blended fuels increases. It was also found that with the increment of ethanol content, the Reid vapor pressure of the blended fuels initially increases to a maximum at 10% ethanol addition, and then decreases. Results of the engine test indicated that using ethanol–gasoline blended fuels, torque output and fuel consumption of the engine slightly increase; CO and HC emissions decrease dramatically as a result of the leaning effect caused by the ethanol addition; and CO2 emission increases because of the improved combustion. Finally, it was noted that NOx emission depends on the engine operating condition rather than the ethanol content.

Biodiesel remains an alternative fuel of interest for use in diesel engines. A common characteristic of biodiesel relative to petroleum diesel, is a lowered heating value (or energy content of the fuel). This review paper discusses the characteristics of biodiesel that has a great influenceon the performance and emission of diesel engine. A lower heating value of the fuel, assuming all other parameters are equal would result in decreased engine torque. Since engine torque is often user-demanded, the lower heating value of the fuel generally translates into increased brake specific fuel consumption.The biodiesel from edible oils isnon-toxic, biodegradable and renewable alternate fuel that can be used as a substitute for diesel in diesel engines. There is some indication that the use of biodiesel fuel can degrade diesel engine oil performance to such an extent that shortening of oil drain intervals is required. Oil, which is fuel-diluted with biodiesel, which is also known to contain unsaturated hydrocarbon bonds would be expected to be more prone to oxidation. Besides, the use of biodiesel leads to the substantial reduction in PM, HC and CO emissions accompanying with the imperceptible power loss, the increase in fuel consumption and the increase in NOx emission on conventional diesel engines with no or fewer modification. Plus, it favors to reduce carbon deposit and wear of the key engine parts. Therefore, the blends of biodiesel, with small content in place of petroleum diesel, can help in controlling air pollution and easing the pressure on scarce resources without significantly sacrificing engine power and economy. However, many further researches on optimization and modification of engine, low temperature performances of engine, new instrumentation, methodology for measurements and etc., should be performed when petroleum diesel is substituted completely by biodiesel. In this study, reports about biodiesel engine performances and emissions, published by highly rated journals in scientific indexes were cited preferentially since the year 2000. From these reports, the effect of biodiesel on engine power, economy, durability, emissions including regulated and non-regulated emissions and the corresponding effect factors are surveyed and analyzed in detail.

The application of wind energy is not a foreign thing, especially in this era of unlimited globalization where humans need green energy to run their daily lives. Therefore, the idea of evaluating the aerodynamic performance of the helical wind turbine blade designs is the major factor for the start-up of this project. Besides, the scope of the study for this project is to develop helical wind turbine CAD models by using SolidWorks software and also perform CFD simulation for the helical wind turbine design by using ANSYS software. This project involves combining the process of Computer-Aided Design (CAD) and Computational Fluid Dynamics (CFD). Computer-Aided Design (CAD) is used to design the wind turbine blade and Computational Fluid Dynamics (CFD) is used to simulate the wind turbine blade. This project is carried upon few blade characteristics tested such as blade length and blade angle and from the simulation, the final degree of torque could be obtained thus enable the power generated to be calculated by using a mathematical equation of power. The results for the best blade angle show that 45 Degree blades produce the highest power. Next, the results for the best blade length show that a 100 cm blade produces more power compare to the other. The 45 Vertical Blade produced less power compare to the commercial design which is 177.96 Watts in the transverse direction but proved more efficient in the longitudinal direction as it generates the power of about 475.76 Watts.

This study presents an analysis of wind power potentials for two meteorological stations in the eastern part of Malaysia using the statistical Weibull distribution method over a period of ten years stretching from 2010 to 2019.As the estimation of the resource potentials is crucial towards the planning of a wind energy project, the primary objective of this study is to reveal the characteristics and potentials of the two selected sites.The results show that the highest annual average wind speed was 3.4 m/s at Kudat station and 2.3 m/s at Santubong station.The maximum shape and scale parameters were respectively 1.68 and 2.88 m/s and both appeared at Kudat station.The wind power density ranged between 9.45 W/m 2 and 24.24 W/m 2 .The maximum energy density at Kudat was 207.60 kWh/m 2 /year and 106.01 kWh/m 2 /year at Santubong.The most probable wind speeds and wind carrying maximum energy were predicted at 1.68 m/s and 4.59 m/s and both speeds were observed at Kudat in 2019.The maximum deviation between observed frequencies and Weibull frequency distributions was around 27%.While the wind power at each site differs considerably, both of these two stations fall outside of the category of pacific northwest national laboratory (PNNL) classifications due to their low mean wind speeds.Nevertheless, it can be categorized for a smaller scale of wind power generation at a wind turbine elevation of more than 10 m.

The present paper aims to study the possibility of dispensing an auxiliary power unit (APU) in an aircraft powered by fossil fuels to reduce air pollution. It particularly seeks to evaluate the amount of power generated by the ram air turbine (RAT) using the novel counter-rotating technique while characterizing its optimum axial distance. The ram air turbine (RAT), which is already equipped in aircrafts, was enhanced to generate the amount of energy produced by the APU. The approach was implemented by a CRRAT system. Six airfoil profiles were tested based on 2D models and the best airfoil was chosen for implantation on the RAT and CRRAT systems. The performance of the conventional single-rotor RAT and CRRAT were analyzed using FLUENT software based on 3D models. The adopted numerical scheme was the Navier–Stokes equation with k–ω SST turbulence modeling. The dynamic mesh and user-defined function (UDF) were used to revolve the rotor turbine via wind. The results indicated that the FX63-137 airfoil profile showed a higher performance in terms of the lift-to-drag ratio compared to the other airfoils. The optimum axial distance between the two rotors was 0.087 m of the rotor diameter and the efficiency of the new CRRAT increased to almost 45% compared to the single-rotor RAT.

Savonius wind turbine is an interesting type of vertical axis wind turbines (VAWTs) which has a low cost of manufacturing, however, this turbine has a relatively low power output compared to the other types of VAWTs. Further study is required to enhance its performance to match the high demand of the power generation in small-scale applications. The main objective of the current study is to enhance the power output coefficient (Cp) of the conventional Savonius rotor by adding two-inner blades to the geometry. The performance assessment was performed for five different angles of inner blades (100 degrees, 120 degrees, 140 degrees, 160 degrees, and 180 degrees). Moreover, the effect of spacing between inner blades was numerically examined for three values of spacing i.e. 0.02, 0.01, and 0.005 m. The current two-dimensional simulation was performed utilizing the Ansys Fluent solver. The simulation results affirmed that the maximum enhancement to be 32.9% compared to the conventional rotor at TSR equal to 0.7 when the spacing between inner blades is 0.005 m with an inner blades angle of 100 degrees. Moreover, results demonstrated that the Ct max is 0.435 at TSR = 0.4 for the rotor with 160 degrees inner blades and a spacing of 0.005 m.

Wind power is sustainable and prevalent virtually all over the globe. However, the conversion efficiency of the conventional single-rotor wind turbine (SRWT) is still far from satisfactory. The dual-rotor counter-rotating concept is among the reliable techniques used to enhance the efficiency of a wind energy conversion device for its renowned effectiveness. This study aims to investigate the performance of a Savonius dual/twin-rotor system, particularly in low-speed wind conditions while employing the counter-rotating technique. The evaluation of this technique is presented in terms of aerodynamic characteristics, including the power and torque coefficients. The results have shown that the new concept was able to improve the performance of the system extensively and was capable of operating in a lower wind speed condition. Compared to a single-rotor system, an additional 42% more torque was possible owing to the existence of a second rotor in the new system. The results have also revealed that the conversion efficiency of the system has been enhanced substantially. A corresponding average power coefficient of up to 28% was achieved. The present technique is thought to be promising for wind energy conversion systems, including sites with poor wind conditions.

Enclosing a wind turbine within a flanged diffuser is an innovative mean to increase the power harvested by turbine blades and it is among the most effective devices for increasing wind turbine energy. The geometric parameters of the empty flanged diffuser contribute efficiently to increase mass flow in the diffuser, hence improve the turbine performance. The study presents developed models of the geometrical parameters of an empty flanged diffuser that suitable for a scaled-down (1-6.5) horizontal axis wind turbine, the geometry parameters were involved the diffuser length, diffuser angle, flange height and flange angle. The geometrical models were verified and CFD investigated in 2-D and 3-D domains. Results obtained from CFD simulations show that, using a compact size of flanged diffuser within optimum geometrical parameters can give well acceptable for flow velocity increase at suggested place for the turbine rotor install. The increase in flow velocity is due to lower pressure at the outlet of the diffuser. As there is also a significant effect of the flange angle on increasing the flow velocity inside the diffuser where the rate of increase in wind velocity at turbine position was calculated for two flange angles (0 degrees and 5 degrees). In another hand, the results also provided information on the velocity contours and velocity streamlines around diffuser geometry.

Shrouding of HAWT in a flanged diffuser is among techniques of wind power augmentation especially in urban areas.In this paper, a small scale of Flanged Diffuser Augmented Wind Turbine (FDAWT) was presented with flanges angle (ϴf) of 0°.The rotor fit for FDAWT was designed based on a modified blade element momentum theory, which adopts on developing the preliminary rotor blade geometry in terms of pitch angle.The modification of the blade pitch angle was based on the maximum wind speeds in the empty flanged diffuser at rotor position along the blade sections.The models of rotor and diffuser were fabricated and experimented in the wind tunnel.The experimental tests were conducted to calculate the power at a different wind velocity ranged 5 -9 m/s.The performance tests were in terms of power coefficient, CP and torque coefficient, CQ as a function of the tip speed ratio as well as maximum power as a function of the wind velocity.The results show the rate of increase in the maximum power producing for the FDAWT with the modified rotor up to 291% more than what it is for the preliminary bare HAWT, while this increase was only 257% for FDAWT with the preliminary rotor.

The Savonius wind turbine is considered as one of the solutions for harvesting the kinetic energy from the wind in the urban areas, due to magnificent features such as, low construction cost, high starting torque, and self-starting ability especially at low wind speed. However, the conventional rotor suffers from low efficiency. Thus, modifying the configuration of the rotor may be an effective solution for providing electricity to the communities with no access to the power grid. Thus, this investigation aims to study numerically the effect of adding two inner blades on the performance of the Savonius wind rotor at low tip speed ratios (TSRs). The simulations are carried out using the two-dimensional simulation with the assist of ANSYS software. For turbulence modelling, the K-ε/realizable model was adopted in this study. Power coefficient (C p ) and torque coefficient (C t ) at various TSRs for the rotor are determined under a constant external overlap of 0.018 m. Furthermore, the effect of space between the inner blades was also investigated using three values of spacing. The simulation results show that the rotor with two inner blades performs better than the same rotor without inner blades at all tested TSRs expect at low considered values of 0.2 and 0.25. The heights Cp was 0.188 with 17.1% performance improvement at TSR = 0.4. Furthermore, the numerical results show that C p values decrease with the decrease of the space between the blades.

The present study investigated the airflow characteristics of wind turbine system to harness wind energy for electric powered pickup truck. The wind turbine consists of the rotating drag-type rotor installed in the duct casing for wind concentrator. The geometry of the wind turbine system was modelled using SolidWorks software. The additional features of guide vane, additional outlet channel and second rotor blade were implemented to improvise the performance of previous design. CFD simulation work was conducted using commercial software of ANSYS Fluent. Initial inlet velocity were set for three different values i.e. 16.7m/s (60 km/h), 25m/s (90km/h) and 33.3m/s (120km/h). The results obtained indicated that the new design of duct casing with guide vane is capable to increase the air speed. The circulated air trapped in the duct casing which caused the negative torque of the rotor blade to occur were significantly reduced and increased the angular velocity as the additional outlet channel was introduced in the system. In addition, the implementation of double rotor blades in the modified design tends to increase the power generated by a factor of 1.5 as compared to the single rotor blade system.

The performance of the single and double blade Savonius rotors are numerically analyzed using the K-ε/realizable turbulence model. The computations are implemented at different values of tipspeed ratio from 0.2 to 0.4 with a step of 0.05. Both rotors have the same dimensions with an external overlap between their blades equals 0.02 m. The results indicate that the double blade rotor performs better than the single blade rotor in terms of power coefficient. In addition, the torque coefficient is improved at all tested values of tip-speed ratio. Furthermore, the results of the simulation show that the maximum power coefficient was 0.163 at tip-speed ratio = 0.4 for the double blade rotor, whereas the maximum improvement of the double blade rotor occurs at tipspeed ratio = 0.2 with a percentage of 11.86% compared to the single blade rotor. Moreover, the highest value of the torque coefficient was 0.524 at tip-speed ratio = 0.2 for the double blade rotor.

New inventions is relating to the idea of mounting a wind turbine for power generating system in vehicles. This study will investigate on the existing energy conversion and storage systems used in standard vehicle's power system. This study involves with a proposed design of a vehicle's wind turbine system. The energy that has been generated by wind turbine will be stored in the 12 volt battery and will then, be distributed to the entire vehicle for the use of the vehicle components. The optimal design for energy conversion system is created based on the review of the existing energy conversion and storage systems which are used in vehicle's power system. A simulation study using NI Multisim (National Instrument Software) is conducted on the energy conversion and storage system that. The objectives of this study are to convert a mechanical energy from the blade to electrical energy to generate 12V voltage and to store it in a 12 volt battery. The 12V battery voltage will then be supplied to a high voltage system, up to 200V voltage capacity. From the analysis that has been done, the energy from a turbine has the potential to generate power to car system. The wind energy is possible to integrate with other existing and renewable energy. At this stage, the energy gained does not replace the existing one but it can be considered as a new energy source in the future energy development

In this study, the meteorological statistics recorded of seven-year wind speed data of the capital city of Jordan, Amman at height 10 m is utilized to assess the potential of wind energy. Also, statistical assessment of wind characteristics is evaluated by the two-parameter Weibull function. Monthly and annual wind speed variation is also analyzed. The study shows that Amman city is more suitable for small-scale wind turbine farms with the current wind speeds. The values of the shape Parameter K, and scale Parameter c show a various ranges between (1-1.5) and (1.5 m/s - 3.5 m/s), respectively. It was also noticed that the annual mean wind speed v̅ is between 2.2 and 3.02 m/s. Results also showed that the highest wind power density is in June whereas the lowest is in October. In wind direction estimation, it was found that most of wind direction for the seven-years is between the southwest and the northwest, i.e. (135°-215°).

The present work focused on solving two dimensional compressible Euler equation based on cell-cantered finite volume discretization technique with the convective terms appear in the Euler equation were evaluated by using Roe scheme [4]. These methods used for solving the flow past through bump with different setting on their boundary conditions. Six different setting of boundary conditions had been applied; three of them are able to provide a convergent solution, while three others tent to diverge. It is clear the result shows that boundary condition plays an important role in determining the flow solution.

ABSTRACT Thin airfoil theory idealizes the flow around a thin airfoil, and addresses an airfoil of zero thickness and infinite wingspan. It is particularly notable in providing a sound theoretical basis for the important properties of airfoils in twodimensional flow. This paper gives attention to the gap between the theory and the numerical experiment data in order to make the classification of NACA airfoils and then proposing a simple guideline on the use of the theory. The twodimensional viscous and incompressible flow around the airfoils is assumed. Several NACA airfoils are considered in the theoretical calculation against the numerical solution. It is found that the theory is applicable for real airfoils within specific range of angle of attack and defined accuracy.