Sajjad Miran

This paper aims to analyze the performances of the interpolation covers method in the enrichment of a standard four-node quadrilateral finite element (FE) solution. The interpolation covers (IC) method has shown to be efficient in the local enrichment of the solution by increasing the polynomial degree of approximation using neighboring elements within a predefined set of covers. The enriched FE approximation is capable of capturing high stress gradients accurately, even using coarse mesh, thereby reducing the computational cost. As reported in existing studies, researchers have used neighboring nodes and polynomial enrichment to construct interpolation covers, but the combined effect of the selection of the number of neighboring nodes and their position in the patches and polynomial enrichment has not explored been yet. This study therefore performs a parametric investigation of these factors for enriched four-node, quadrilateral-shell finite elements. Two numerical applications are treated to demonstrate the effectiveness of the method. It is found that the selection of the closest neighboring nodes results in high solution accuracy.

The rising need for sustainable energy sources and less dependence on fossil fuels leads to research on alternative fuels. Motorcycles across a wide range of categories often use single-cylinder, spark-ignition, four-stroke engines. This research analyzes the performance of a single-cylinder engine with different bioethanol–gasoline blends at varying engine speeds. The present study used the numerical simulation tool AVL BOOST for one-dimensional simulation. A numerical model was developed for the single-cylinder engine in order to determine its performance, where a number of fuel mixtures were considered at different engine speeds. Parameters such as power, torque, engine efficiency, temperature, BMEP, BSFC, and fuel consumption were obtained to analyze the engine performance. The current results indicate that engines operating on lower ethanol blends achieve maximum power output at lower speeds. The E20 blend produces 12.29% more power and 4% more torque than gasoline. Additionally, E20 demonstrates a 2.89% increase in mechanical efficiency compared to gasoline. The E30 blend performs similarly to E20 and shows potential for reduced fuel consumption at lower speeds, though only E20 exhibits marginal power gains at lower speeds, achieving 52% more power than gasoline. Furthermore, the results highlight that both power and indicated efficiency increase with higher ethanol content in the blends, while the brake mean effective pressure (BMEP) slightly decreases after 2000 RPM. The brake specific fuel consumption (BSFC) ranges from 0.6 to 0.9 kg/kw.h Fuel consumption rises gradually with engine speed; however, after 2000 RPM, fuel consumption using ethanol (E0) increases significantly. Each blend recorded slightly different exhaust gas temperatures. Overall, the findings identify E20 as a promising alternative to pure gasoline for the investigated single-cylinder engine, offering improved power output, torque, and mechanical efficiency. This study provides numerical insights into the influence of ethanol–gasoline blending ratios on motorcycle engine performance and supports the potential use of bio-ethanol blends as a means of improving engine performance and reducing dependence on conventional fossil fuels.

Modern automotive, aerospace, and manufacturing sectors use tungsten inert gas (TIG) welding widely as a critical procedure due to the weld's quality and joint efficiency. In this study, mechanical characterization of TIG-welded joints of high strength low alloy (HSLA) steel with two different grades (S1 and S2) was performed experimentally and mechanical properties were calculated in terms of hardness profile along the weldment and load-displacement curves. True stress-strain curves of base metal, heat-affected zone, and melted zones were used for calibration of the 8-node solid numerical model. The highest hardness value of 386 HV was obtained in the melted zone whereas a softening zone was observed in the heat-affected zone (HAZ) of S2 where the Vicker's microhardness value was 270 HV. During the comparison of simulation results with experimental data, it was found that the overall error was less than 5% which reflects a good accuracy of material models used for numerical modeling. A higher ultimate tensile strength was found in similar S1-S1 steel joints as compared to similar S2-S2 and dissimilar S1-S2 steel joints. Furthermore, the results of simulations revealed that the maximum von Mises stress (1050 MPa) concentrations were found in the HAZ of a similar S1-S1 welded joint, whereas the minimum von Mises stresses (880 MPa) in S2-S2 welded joint, and intermediate von Mises stresses (1010 MPa) on the side of S1 HAZ in S1-S2 dissimilar welded joint. The results of simulations and experimental study of TIG welding joints show good agreement with reasonable accuracy.

Power augmentation in a small-scale horizontal axis wind turbine, with its rotor encased in a flanged diffuser is explored. The power output of the wind turbine varies with changes in the diffuser design and the resulting back pressure. Reduction in this back pressure also results in early flow separation at the diffuser surface, which hinders turbine performance. The main aim of this study is to numerically investigate the local configuration of the wind turbine location inside the diffuser by varying diffuser angles and wind speeds. Therefore, shroud and flange were modeled and analyzed using the computational fluid dynamic (CFD) analyses and experiments were performed at two wind speeds 6 m/s and 8 m/s with and without the diffuser for model validation. The divergence angle of 4° was found to have no flow separation, thus maximizing flow rate. The proposed design shows wind speed improvement of up to 1.68 times compared to the baseline configuration. The corresponding optimum flange height was found to be 250 mm. However, increasing the divergence angle had a similar output. The dimensionless location of wind turbine was found to be between 0.45 and 0.5 for 2° and 4° divergence angle respectively. Furthermore, the maximum augmentation location varies with wind speed and diffuser’s divergence angle as described by dimensionless location of wind turbine, thus presenting a noteworthy contribution to the horizontal axis wind turbine area with the flanged diffuser.

The electrochemical treatment of canal water was investigated in a batch-wise system in the presence of stainless steel 316-grade electrodes. Three effective process parameters, including current density, reaction time, and electrode spacing, were evaluated in the range of 0.25–2.5 mA/cm², 1–10 min, and 0.5–2.5 cm, respectively. Operational variables of electrochemical disinfection are optimized in response surface methodology (RSM) using Box–Behnken design. Before electrochemical disinfection, a pretreatment process of coagulants mixing for turbidity removal was conducted. Results revealed that a 10 ppm dosage of Ferric chloride (FeCl₃.6H₂O) and alum (Al₂(SO₄)₃·16H₂O) at neutral pH is appropriate. Furthermore, the RSM analysis shows that interelectrode spacing is the most prominent factor affecting the disinfection performance, and increasing electrode spacing inversely affects the disinfection efficiency. Results revealed that 1.52 mA/cm² current density, 6.35 min reaction time, and 1.13 cm of electrode spacing are the optimum conditions, resulting in a statistically 98.08% disinfection of the total coliform. The energy required for electrochemically disinfection of water at optimum conditions was 0.256 kWh/m³.

Renewable energy resources are promising in power generation due to their sustainability aspect and environment friendliness as they are means of pollution free power production. Wind energy.y is utilized for power production with the help of wind turbines. The offshore and onshore windfarms consisting of horizontal axis wind turbines are major contributors in the wind energy. However, this type of turbine is not domestically viable mainly due to limitations of directionality and noise. Vertical axis wind turbines do not have these constraints and may blend in the urban environments. In built environments, the wind flow is quite complex due to large scale effects and turbulence. In this paper, the academic building of a university is studied as a possible platform for harnessing the wind energy resources. This case study is performed on academic blocks of University of Gujrat. These building environments were modeled and analyzed with computational fluid dynamic software to model the wind behavior on the building roof top. These results show that there is potential in setting up micro windfarms for the academic environments. The simulation for single building showed a potential for 61.8kW whereas this potential decreased substantially when terrain effects are considered using the circular arrangement for the simulation.