The wind is an energy source that has the properties of a clean, free, and readily available energy source. However, the efficiency of the existing rotors used to harness wind power is still not satisfactory. Thus, in this current study, the development and aerodynamic performance investigation of ten NACA airfoils comprising of five symmetrical and five non-symmetrical airfoils have been analyzed through the computational fluids dynamic (CFD) simulation approach. The main motive of this study was to investigate the aerodynamic performance of NACA airfoils to be used on a vertical axis wind turbine (VAWT), which will assist in further understanding the physics of the interaction between airflow and the wind turbine blades. The simulation was performed using two-dimensional computational models based on an unsteady state K-omega Shear Stress Transport (SST) turbulence model. This study covers a parametric study based on the variations of tip-speed ratios and constant wind velocity. The aerodynamic performances are evaluated in terms of torque, torque coefficient, and also power coefficient. The performance of NACA0018 was found to be the best among the other airfoils with a power coefficient of 0.3. NACA0010 displayed the lowest power coefficient among the other airfoils but had a more extensive operating range compared to the other airfoils. However, for non-symmetrical NACA airfoils, NACA2421 scored the highest power coefficient, followed by NACA4412. It was also found that most of the non-symmetrical NACA airfoils can operate at a higher range of tip-speed ratios compared to the symmetrical NACA airfoils.

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Wind power is an energy source that is becoming an alternative to burning fossil fuels that may harm the environment during operations due to the emission of harmful gases. In this study, simulation and performance investigations of a counter-rotating vertical axis wind turbine (VAWT) based on the Savonius S-type rotor have been analysed through a computational simulation approach. The foremost motive of this study is to widen the operating wind speed range of the counter-rotating concept in a VAWT while enhancing the conversion efficiency of a single-rotor VAWT system. The 3D simulations were performed based on the K-omega shear stress transport (SST) turbulence model. The results have shown that the counter-rotating model possesses better performance characteristics in terms of torque, power and their corresponding coefficients compared to a single-rotor design of a wind turbine. A maximum output of more than two times was obtained from the new CRWT system compared to that of a single-rotor wind turbine (SRWT). Moreover, the output of the top rotor was higher than the bottom rotor due to the increased higher rotational speed of the top rotor.

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This paper presents the modeling the drying process of shell mould layering process for the ceramic shell mould fabrication process. As this process involves the repeated drying of the different wetted/saturated layers, therefore modeling of this phenomena involve a sequent approach to tackle the whole development of shell mould layering process. In this work an Ab-Initia approach was selected as the best simulation technique to map the drying mechanism. Saturation or moisture content was selected as the best parameter that will represent the drying of layering process. Using FEM with quadrilateral shape mapping of several interested points were selected to predict the moisture/saturation movement during the drying of shell layering stages. Standard drying time with 2 hours and early drying time were chosen to measure the moisture movement as layer added to the previous dried coated shell or layers. This complex mechanism of drying and penetration layering shell were then numerically solve with fully implicit backward time stepping scheme. Hopefully, this model and can be used to measure the complex movement of the main parameter i.e saturation/temperature in the drying process of multilayer system which is sometimes impossible directly measured under experimental technique

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.