Journal of Applied Engineering Design and Simulation

Assessing the Impact of Dual Alcohol Blends on Diesel Engine Performance and Exhaust Emissions

2024-09-06T18:39:35+08:00

The increasing reliance on diesel fuel has heightened concerns about depleting fossil fuel reserves and environmental impacts. In response, researchers are exploring alternative fuel options, such as blends of alcohol and diesel, to improve sustainability. This study investigates the performance and emissions characteristics of several ethanol, methanol, and diethyl ether (DEE) blends with biodiesel and diesel. The tested fuel blends include B10 (90% diesel, 10% biodiesel), BDE (75% diesel, 10% biodiesel, 15% ethanol), BDE2DEE (75% diesel, 10% biodiesel, 15% ethanol, 2% DEE), BDE5DEE (75% diesel, 10% biodiesel, 15% ethanol, 5% DEE), and MBD2DEE (75% diesel, 10% biodiesel, 15% methanol, 2% DEE). Engine performance was evaluated in terms of brake-specific fuel consumption (BSFC), brake power, exhaust gas temperature, and mass and volume flow rates at varying engine loads. The results demonstrate that fuel blends with diethyl ether, particularly BDE5DEE, exhibited superior performance in reducing emissions. NOx emissions decreased by up to 16.2%, while CO2 emissions were reduced by 15.0%. Additionally, blends with diethyl ether lowered brake-specific fuel consumption by 30.7% compared to standard diesel (B10). The blend MBD2DEE, which includes methanol, delivered the highest brake power at higher loads (75%), peaking at 2.91 kW, indicating its strong potential for high-load applications. These findings suggest that dual alcohol-diesel blends, especially those containing diethyl ethers, offer a promising route for improving fuel efficiency and reducing harmful emissions, making them viable alternatives to traditional diesel fuel.

Numerical Analysis on the Effect of Building Spacing and Podium on the Flow Structure Over High Rise Residential Buildings

2024-09-18T15:28:15+08:00

Urban environments with high-rise buildings often experience intensified wind speeds at the pedestrian level, which can compromise comfort and safety. The growing demand for urban housing has led to the proliferation of such buildings, but the impact of building geometry and configuration on local wind conditions remains underexplored, particularly concerning the presence of podium structures. This study addresses the critical issue of pedestrian-level wind (PLW) by investigating how the spacing between buildings and the inclusion of podiums affect wind dynamics. Using computational fluid dynamics (CFD) simulations, the study models wind flow around two high-rise residential buildings arranged back-to-back under different spacing configurations (0.16H, 0.31H, and 0.63H) with and without podiums. The primary objective is to assess wind speed ratios and vortex formations to identify optimal design configurations for enhancing pedestrian comfort and safety. The results show that building spacing of 0.31H without podiums yields the lowest wind speed ratio at the pedestrian level, enhancing safety. The introduction of a podium significantly alters wind flow patterns, particularly by increasing downwash flow and generating larger vortices above the podium level, which can exacerbate wind speeds at higher elevations. These findings underscore the importance of careful urban design considerations, particularly regarding building spacing and podium integration, to mitigate adverse wind effects. The study provides actionable insights for architects and urban planners to create wind-sensitive designs that improve the quality of life in densely built environments.

CFD Analysis of 500W Centrifugal Compressor Performance

2024-09-02T10:05:43+08:00

This paper used Computational Fluid Dynamics (CFD) to analyse the performance of a 500W centrifugal compressor, aiming to develop a comprehensive performance map under various operating conditions. The methodology includes stages such as geometry and grid generation, mesh generation, boundary condition setup, and CFD analysis using ANSYS software. The compressor blade profile was generated using ANSYS BladeGen, followed by meshing that consists of roughly 446,886 nodes and 417,312 elements via ANSYS TurboGrid. Boundary conditions were established by using the CFX-Pre, detailing the inlet and outlet conditions, such as mass flow rate, total temperature, and total pressure. The CFD simulations were conducted using CFX-Solver for 500 iterations, targeting a residual mean square (RMS) of 1 × 10-5, and the results were analysed using CFX-Post. The analysis was conducted under ambient conditions with a mass flow rate ranging from 0.01 kg/s to 0.065 kg/s and speeds of 60,000 rpm, 70,000 rpm, and 80,000 rpm. The expected outcomes include detailed performance maps that provide valuable insights into parameters like Mass Flow Parameter (MFP), Pressure Ratio (PR), and Efficiency (η) across different operating conditions. By employing the k-ε turbulence model in ANSYS CFX, the project aims to offer significant insights into the compressor's performance characteristics. The analysis, conducted under ambient conditions with a mass flow rate ranging from 0.01 kg/s to 0.065 kg/s and speeds of 60,000 rpm, 70,000 rpm, and 80,000 rpm, yielded significant results. The maximum power achieved at the design speed was 771 W at a mass flow rate of 0.05 kg/s. The maximum efficiency recorded was 77.8% at the same mass flow rate, with the efficiency average around 65.5% across the design speed.

Modelling and Simulation of Cyclic Nanoindentation for Y-TZP Ceramic

2024-09-17T20:54:46+08:00

Cyclic nanoindentation is a robust experimental method that enables an in-depth analysis of how materials behave mechanically under repeated loading conditions. The aim of this study is to utilize the cyclic nanoindentation technique in order to assess the mechanical characteristics, including elastic and plastic deformations, of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) ceramic material through simulation. A two dimensional Finite Element Analysis (FEA) model is employed to create a nanoindentation simulation with a Berkovich indenter. The cyclic nanoindentation simulation model provides the outcome of the sample's deformation response and the load-displacement curve for each loading cycle of peak load of 500 mN. This model builds upon our previous research with Saedon et al., where we successfully replicated the load-displacement curve obtained by earlier researchers through a single nanoindentation simulation. Given that the sample model is reliable, the results achieved with Y-TZP ceramic are also depandable. In conclusion, this research has successfully replicated the cyclic nanoindentation method using a Berkovich indenter simulation to analyse and understand the mechanical characteristics of Y-TZP ceramic, which is commonly employed in dental prosthetics.

Evaluation of Tribological Performances of Palm Oil-Blended Food Grade Lubrication

2024-09-26T10:44:33+08:00

Conventional industrial lubricants from mineral oil are recognized for their harmful effects on both humans and the environment. It has driven a worldwide shift to embrace food-grade lubricant due to their biodegradability, favourable viscosity, cost-effectiveness, and wide availability. This study evaluates the tribological performances of blended palm oil, assessing its suitability as an eco-friendly and efficient alternative in the industry. Although there have been numerous studies exploring the tribological performances of vegetable oils, research on the food-grade lubrication using a blend of palm oil and industrial gear oil still has potential for further improvement and advancement. Therefore, this investigation intends to measure the wear rate and coefficient of friction using the Pin-on-Disc tribometer according ASTM G-99 standard. Using industrial gear oil as the base, 15 different samples with concentrations of 0%, 15%, and 30% palm oil were tested under varying applied loads, ranging from 30N - 60N, and speeds ranging from 600 rpm - 900 rpm. Utilizing the Surftest machine SV600, both samples of S7L3P15 and S7L4P15 indicated the lowest surface roughness (Ra), which is 0.04 µm. Furthermore, the FTIR spectrometer demonstrated the presence of aliphatic hydrocarbons, olefins, and esters in the functional groups of both G70P30 and G85P15 sample oils. Beyond this point, out of 15 samples tested, 12 samples had wear rates under 50 (10^-6) mm³/Nm and coefficients of friction below 0.1 in the Pin on Disc test. G70P30 is the optimum biolubricant concentration because it reduces wear rate and friction more than G100P0 and G85P15. In conclusion, the blended palm oil can increase the development of biodegradable and environment-friendly lubricant oil without concerns about downgrading the tribological performances.

Comparative Computational Modal Analysis of Uniform and Tapered Plates

2024-09-13T22:59:58+08:00

Thickness variation in structures has significant influence in their structural properties which makes it as an important consideration in engineering design. Varying thickness profile has gained many attention in its application due to the potential to optimise performance and reduce material usage. However, the impact of these thickness variations on modal behaviour of structures has not been fully understood. This study aims to investigate the effects of thickness variation on the modal properties of structural plates. Two plates with different configuration were modelled in MSC.Nastrab/Patran Software in which one plate has uniform thickness while the other has tapered thickness. Finite element modal analysis was performed to determine the natural frequencies and mode shapes of both plates. The results revealed that the plate with varying thickness has lower natural frequencies and its mode shapes are more complex and asymmetric compared to the plates with uniform thickness. These findings suggest that thickness variation can significantly alter the vibrational characteristics of structures which is important in design optimization of applications such as automotive and aerospace engineering.

Bending and Free Vibration Analysis of Functionally Graded Sandwich Plates with porosity using Higher-Order Shear Deformation Theory

2024-09-23T14:37:13+08:00

In this paper, for the first time, the bending and free vibration analysis of porous functionally graded sandwich (PFGS) plates is investigated using a higher-order shear deformation theory (HSDT) C0 type and finite element model. This construction consists of a single homogenous ceramic core and two distinct functionally graded skins. The mechanical results related to bending and free vibration behaviours of it are searched using the Matlab software. The other plates with different materials or arbitrary forms can use this code as well in the future. To verify the procedure's potential of use, the study's findings are contrasted with those of previous studies in the literature. Additionally, the effects of a number of parameters on the bending and vibration of PFGS plates are provided, including the porosity factor, volume fraction index, and geometric ratio. These results show that the distribution of porosity plays a significant role in the mechanical properties of PFGS plates.