Journal of Research and Applications in Mechanical Engineering

In-Depth Analysis of Municipal Solid Waste's Heating Value for Green and Clean Renewable Energy in the context of Way of Live

K. Laohalidanond, T. Wiangthong, S. Kerdsuwan — Mon, 03 Jun 2024 00:00:00 +0700

The increase in global waste levels and the decrease in fossil energy sources are major concerns around the world. Waste-to-Energy (WtE) technologies have been used to transform Municipal Solid Waste (MSW) into energy and minimize concerns about global waste levels and fossil energy. However, MSW presents a number of challenges when used as a feedstock for energy production due to its heterogeneous composition, low energy content, and high moisture. To design waste incineration power plants, it is necessary to measure the Higher Heating Value (HHV) and the composition characteristics of MSW. Therefore, this paper proposes a most suitable correlations based on ultimate analysis to accurately estimate the HHV of MSW. The correlations consider all parameters that influence the HHV of MSW. MSW was collected from both urban and rural areas. Ultimate analysis was performed to characterize the chemical composition of MSW from both areas, and the HHV was also determined to compare the differences in the chemical properties of MSW from different areas. This work helps save experimentation costs and assists in the design and management of waste incineration plants.

Comparison of Disc Brake Squeal between Ordinary and Drilled Brake Discs Using Finite Element Method

A. Sodsong, C. Suphawimol, R. Kittipichai — Mon, 03 Jun 2024 00:00:00 +0700

During the braking of the automobile, the brake squeal is a direct concern for the driver. Sometimes, the automaker loses revenue from the customer's warranty claims. The automaker needs to solve or alleviate the squealing noise during the brake action. The study aimed to compare the disc brake squeal of general and drilled brake discs. The disc brake squeal is an instability of the disc brake system. One popular theory used in the analysis is Complex Eigenvalue Analysis and simulation using Finite Element Technique. In this work, three models of brake discs were compared: an ordinary brake disc and two drilled brake discs. For drilled brake discs, the first and second models had 30 and 60 holes on the disc, respectively. The study revealed that a more stiffness structure generates higher frequencies than a flexible structure. Each model generated a different amount of unstable frequency modes.

Nonlinear Analysis of New Electromagnetic Vibration Actuator

H. Yaguchi, R. Sato — Mon, 03 Jun 2024 00:00:00 +0700

The inspection and maintenance of infrastructure such as bridges, which may collapse during an earthquake, is important. Numerous robots have been proposed for structural inspections. These robots have complicated mechanisms and require the adhered device to have a relatively large weight. The authors previously proposed an electromagnetic vibration actuator for structural inspection. However, an analysis that considers the nonlinearity of the translational spring was not performed for this actuator. In this study, a dynamic analysis that considers the nonlinearity of the vibration component is performed. Furthermore, a prototype of the vibration actuator is constructed and its movement characteristics are measured. The measurement and theoretical analysis results are in relatively good agreement, verifying the validity of the theoretical analysis. Based on the theoretical analysis, the movement characteristics of the vibration actuator can be calculated for various parameter values. This paper demonstrates the possibility of applying the theoretical analysis to calculations for other highly nonlinear models in which the electromagnetic force and vibration systems are combined.

Flow Characteristics of Plane Jets Passing Over Two-Dimensional Flat Plates

K. Ishiwata, K. Nishibe, K. Sato — Mon, 03 Jun 2024 00:00:00 +0700

A simple model was proposed to consider situations in which jet flows pass over seats in high-speed trains and aircraft cabins. Efforts were made to understand the flow characteristics inside the cavity when jet flows pass over partition plates (2D flat plate arrays). Flow visualization experiments and numerical calculations were conducted, and various geometric conditions were investigated for typical flow patterns. It was demonstrated that the inflow rate into the cavity and size of the recirculation region formed inside the cavity depended on the offset ratio and length of the partition plate. In particular, the influence of the distance from the slot to the tip of the partition plate on the internal flow characteristics of the cavity was discussed.

Nondestructive Evaluation of Three-Dimensional Plastic Strains Based on Nonlinear Inverse Analysis Using Displacements

S. Fujii, M. Ogawa — Mon, 03 Jun 2024 00:00:00 +0700

In order to achieve a rapid supply of electricity from power plants after an earthquake, the integrity of power plants needs to be assessed more quickly and accurately. Currently, hardness tests are used as a method to evaluate the plastic strain of pipes after a relatively large earthquake, but only the outer surface of the pipes can be measured. Furthermore, it cannot be regarded as a non-destructive test, as the hardness test produces indentations. There is a method to estimate the three-dimensional plastic strain, which is the cause of the displacement, from the non-destructively measured surface displacement by inverse problem analysis. The aim of this study is to apply this method to the non-destructive estimation of plastic strains for whole structure using displacements caused by external forces, and to verify its effectiveness by numerical analysis. Here, the relationship between plastic strains and displacements becomes non-linear when relatively large plastic strain is generated. In order to solve such a non-linear problem, an inverse analysis method using iterative calculations was introduced. In order to verify the principle of the method, a simple three-point bending model is used in this numerical analysis and its plastic strains are estimated using the surface displacements. The numerical results show that the plastic strain distribution can be estimated with relatively high accuracy for large deformation where the relation between plastic strains and displacements becomes non-linear.

Design and Analysis of Shear Pin of Lever Arm in Generator Circuit Breaker Using Finite Element Method

K. Jaiyen, W. Rangsri — Sun, 09 Jun 2024 00:00:00 +0700

Interruption in mechanism of the generator circuit breaker is a main cause of an overload impact and fracture of lever arm, resulting in suspension of the power plant’s electricity transmission. Recently, shear pin has gained more interest owing to its ability to be a force-transmitting and break-away parts. Herein, finite element simulation analysis was investigated using Abaqus explicit software. Three-dimensional (3D) model of the lever arm and clevis pin were simulated based on actual dimension and velocity for analysing stress and force between the lever arm and pin due to impact. Notch and hollow pins with different shear cross-sectional areas were also simulated using the similar model. Deformation, energy dissipation, and failure load of various shear pin dimensions were investigated to yield the suitable shear pin for preventing lever arm’s fracture. The great potential notch pin with 6 mm in-depth to protect the lever arm from damages could be assumed.

Static Bending Test of a Carbon Fiber Posterior Leaf Spring Ankle Foot Orthoses (PLS-AFOs)

P. Akarasereenont, A. Wisessint — Sun, 09 Jun 2024 00:00:00 +0700

Drop foot is a condition that limits the ability to move the foot upward, which can impair walking. Carbon fiber ankle-foot orthoses (AFOs) are commonly used to assist people with drop foot, but they can be expensive and difficult to obtain. This study investigated the use of 3D printing to create carbon fiber posterior leaf spring AFOs (PLS-AFOs). The foot part or Heel support component of PLS-AFOs were printed using carbon fiber and polylactic acid (PLA) filaments. The strength, weight, and load-displacement relationship of the PLS-AFOs were compared. The results showed that PLS-AFOs made from carbon fiber were stronger, and had a better load-displacement relationship than those made from PLA. This suggests that 3D printing can be used to create affordable and accessible carbon fiber PLS-AFOs. The findings of this study will be used to design a new generation of PLS-AFOs that are stronger, and more affordable than traditional AFOs, making them more accessible to people with drop foot.

Investigating Adaptive CPG-based Control of a Snake Robot with Switch Signal Input for Maneuvering in Varying Environments

P. Ngamkajornwiwat, N. Pothita — Sun, 16 Jun 2024 00:00:00 +0700

This study makes an essential contribution to robotics by revealing how to manage snake robots using adaptive Central Pattern Generators (CPGs) with switch signal input. The work optimizes CPG hyperparameters, characterizing robot behavior to improve navigation in obstacles and limited areas. Three indices are used to evaluate parameter adjustments: index based on moving time, index based on movement frequency, and index based on movement path. Quantitative investigation reveals how these hyperparameters influence the efficiency and adaptability of snake robots across situations. The findings emphasize the effectiveness of the proposed methodology by emphasizing quantitative values resulting from parameter modifications. The work uses stringent testing criteria to identify ideal parameter values (𝜇 = 0.8, A = 0.007, B = 0.005), boosting the approach's resilience and applicability.

Effect of Plane Walls on Flow Characteristics of Primary Jets Controlled by Secondary Flow

H. Tezuka, K. Yabu, K. Nishibe, D. Kang, K. Sato — Sun, 16 Jun 2024 00:00:00 +0700

The method for controlling the direction of primary jets by secondary flow is called fluid thrust vectoring. It was originally studied for application in aircraft attitude control, where it was expected to reduce fuel consumption and improve motion performance. It has been demonstrated that the direction of the primary jet can be adjusted by adjusting the momentum of the secondary flow generated near a curved surface (Coanda surface), such as a cylinder. However, there is limited research applying the abovementioned method to fields such as aviation for flows other than external flows. To use this method for internal flows, such as airflow control in a room, knowledge of the geometric boundaries near the jet flow is required. That is, the interference problem between the jet and wall boundaries must be investigated to realize jet direction control using secondary flows in various fields. Thus, this study investigated the effects of wall length and step height (offset ratio) on the flow characteristics of jets controlled by secondary flow near the Coanda surface. Typical flow patterns are presented in this paper, and the jet deflection characteristics are discussed primarily through flow visualization and velocity distribution measurements.

BDF Synthesis using Clamshell as Ecofriendly Catalyst

J. Liang, Y. Jiang, N. Zhu — Sun, 16 Jun 2024 00:00:00 +0700

BDF (Bio-diesel Fuel) is regarded as a kind of SAF (Sustainable Aviation Fuel) that can be used for diesel engine. The basic method of producing BDF is based on transesterification reaction where vegetable oil reacts with methanol under conditions of proper catalyst and temperature. So far, catalysts such as NaOH, KOH, CaO and H₂SO₄ have been suggested for BDF synthesis. Though higher BDF yield ratio up to 95% was reached, after treatment of using large quantity of water to wash the remained catalyst out of the produced BDF caused some environmental problems. For example, to produce 900L BDF, usually 60L water is needed. In order to deal with this problem, we have successfully employed eggshell as the ecofriendly catalyst to produce BDF under microwave irradiation. In this case, even water-washing is not applied to BDF-producing process, BDF yield ratio could reach 99.5%. In this paper, we aim to make suggestions of using clamshell to synthesize BDF. Firstly, calm shell is milled and prepared as catalyst. Secondly, it is characterized. Thirdly microwave irradiation based BDF synthesis are conducted under a certain of experimental conditions. Fourthly, The BDF yield ratio is measured. Finally, the physical properties such as density and viscosity are invested. It is found that the BDF ratio could reach 87.98% and the specific gravity was 0.895.

Radiant Floor and Traditional Cooling System Applications in Agricultural Product Storages

P. Janthasri, A. Pramuanjaroenkij, S. Kakaç, C. Chungchoo — Sun, 16 Jun 2024 00:00:00 +0700

The fluctuated temperatures and relative humidity inside storages are not suitable for food and agricultural products since these parameters directly affect product moisture contents, freshness, and integrity. With a limited amount of research, in this work, traditional vapor compression (fixed- and variable-speed compressors) and radiant floor cooling systems were experimentally investigated as solo and combined systems in no heat load and heat-loaded cooling-storage rooms. The latter systems were newly introduced in storage applications. When the compression systems were examined, they were set at 18°C and 22°C to find their operating effects. The results showed that the radiant floor cooling systems not only assisted both compression systems to consume less energy, but the floor cooling systems also created fewer fluctuating conditions. The combined systems were highly recommended to be used in storages containing products that were sensitive to fluctuating conditions such as ready-to-eat and fresh fruit products. The energy consumption investigation imparted valuable information for operation costs.

Hydrogen Generation based on Chemical Reaction and its Application

Y. Takeuchi, N. Zhu, K. Amano, K. Fukuda — Sun, 16 Jun 2024 00:00:00 +0700

In recent years, the effects of global warming due to CO₂ emissions have become serious. Since internal combustion engines (ICEs) where gasoline or diesel are used as fuel release huge amount of CO₂, attentions have been paid to the new decarbonization countermeasures of Ices. Among them, H₂ is regarded as a kind of eco-friendly fuel not only for fuel cell but also for Ices. So far, we have modified a gasoline electric power generator for using H₂ as fuel by amounting a surge tank with a special intaking flow system. Though many useful results have been obtained, problems such as H₂ supply method for on-site operation or backfire phenomenon at high load still remain. Therefore, in current paper, in order to deal with the above-mentioned problems. Firstly, H₂ generation method based on chemical reaction for onsite operation is suggested and verified. Secondly, a new intake flow system for stable operation was designed and manufactured based on simulation and engine performance test was experimentally investigated. Finally, engine operation test using H₂ generated by chemical reaction on-site was conducted. As a result, the maximum H₂ generation was 29.3 L/min, and the error from the theoretical value was 2.4 %. In engine performance test for new Intaking flow system, the maxi mum output was 900 W, and the thermal efficiency was 19.0%. In engine operation testing generated H₂ on-site, the engine speed decreased by up to 900 rpm compared to compressed H₂.

Multi-Objective Optimization of Lightweight Inboard Bearing Design for High-Speed Railway Axle

T. Nwe, A. Tantrapiwat, M. Pimsarn — Sun, 30 Jun 2024 00:00:00 +0700

This research delves into the intricate balance between reducing axle weight and maintaining structural integrity in high-speed rail transportation. Focusing on the critical factor of weight reduction in high-speed axle design, the study employs finite element simulations and standard calculations to systematically explore inboard and outboard bearing wheelsets. Particularly noteworthy is the examination of inboard bearing axles, revealing advantages in mass reduction, deflection, and stress mitigation, with an 8% lower weight than outboard bearing axles. Utilizing multi-objective optimization, the research achieves a remarkable 4% reduction in mass and an associated 4% decrease in stress, resulting in a 12% mass reduction compared to traditional axles. The study also enhances fatigue resistance, demonstrated through radial fatigue reverse factor (FRF) analysis. With a detailed methodology involving ABAQUS modeling, Python scripting, and optimization using the Pointer algorithm in Isight, this research adeptly navigates the trade-off, significantly contributing to the advancement of railway transportation systems.

Efficiency and Control: Modelling and Validation of an Electric Fan Bus Cooling System

A. Kosin, A. Kosiyanurak, T. Sri-on, N. Pothi, J. Srisertpol — Sun, 30 Jun 2024 00:00:00 +0700

The cooling systems in the majority of passenger buses typically depend on mechanical or hydraulic cooling systems. These systems utilize the engine's generated energy to function, leading to increased engine workload and higher fuel consumption. However, an electric cooling system presents the advantage of reducing the engine's workload and providing enhanced control. This paper focuses on modelling, validating, and presenting experimental results of an electric fan cooling system. Based on the accuracy assessment of the heat exchange system's mathematical model studied in this research, the evaluation was conducted using the Root Mean Square Error (RMSE) of the mathematical model's response compared to the actual system response obtained from experiments. It was observed that the RMSE of the outlet air temperature is 0.50, and the RMSE of the cooling water temperature at the water outlet is 0.21. Therefore, it can be concluded that the estimated mathematical model is accurate and closely approximates the real system. Additionally, it aims to utilize the benefits of the mathematical model to design a control system specifically tailored to the engine's operating conditions.

Rolling Resistance Evaluation of Non-pneumatic Tire with Linked Zig-zag Structure using Scale Model

Sun, 30 Jun 2024 00:00:00 +0700

In automobiles, it is increasingly important to reduce the frequency of maintenance due to accidental failures, and puncture-free non-pneumatic tires (NPT, airless tires) are expected to be used. We proposed a new NPT with a linked zig-zag structure to reduce rolling resistance (RR). Finite element analysis (FEA) results showed that NPT with a linked zig-zag structure can reduce RR more than other NPTs. The purpose of this paper is to verify the reduction of RR by the proposed structure using an actual machine. In order to verify the actual machine, we formulated the equivalent stiffness of the proposed structure and designed an actual scale model that can be prototyped. As a result of the rolling test, we were able to verify the reduction of RR in the scale model as well as the structural analysis.