Computational Engineering Commons^™

Effect Of Various Canopy Shapes On The Drag Coefficient Of Pickup Trucks, Khairil Anwar, Muhammad Syaiful Fadly, Muhammad Wahyu Hermanto

Journal of Mechanical Engineering Science and Technology (JMEST)

The aerodynamic performance of light commercial vehicles, such as the Suzuki Carry, plays a crucial role in their fuel economy and road stability. One typical add-on, a canopy, often changes that airflow and, as a result, alters the drag acting on the vehicle. In this study, three different canopy shapes, flat, curved, and triangular, were examined to understand how each one affects the drag coefficient (Cd). To investigate this, both wind tunnel trials and CFD runs were conducted to track the airflow and measure any changes in drag with greater detail. For reference, the exact vehicle without a canopy was …

Signal Modeling Of High Purity Germanium Detectors, Brooke Parker Thibodeau

Honors Scholar Theses

Pulse shape analysis can be used to analyze radiation incident on a semiconductor diode detector. Finite element analysis (FEA) can be used to simulate high purity germanium detectors with user-specified geometry, impurity concentration, and bias voltage. Subsequent streamline calculation can be used to conduct pulse shape analysis for single and multiple site gamma-ray interactions within the detector volume. Cross sections of the detector can be visualized by contour plots of the electric field, drift velocity magnitude, and collection time, as well as t30 and t90 rise-time values.

Mechanistic Insights Into Polymer-Assisted Graphene Exfoliation: The Roles Of Velocity, Adhesion, Cohesion, Temperature, Peeling Mode, And Edge Defect Via Coarse-Grained Molecular Dynamics, Linjiale Dai

All Theses

Graphene exfoliation is a critical step in the fabrication of high-quality graphene

layers. However, the underlying fracture mechanisms remain poorly understood. In this

work, I employed coarse-grained (CG) molecular dynamics (MD) simulations to

investigate how factors such as interfacial binding energy, substrate cohesion, temperature,

peeling mode, and edge defects influence the outcome of the exfoliation process. To model

polymer-assisted mechanical exfoliation, I used a finite-size system in which multilayer

graphene (MLG) is sandwiched between two thin polymer films. Leveraging the

spatiotemporal efficiency of the CG model, I performed fifty simulation iterations per

parameter set and analyzed the results from a …

Assessment Of H2s-Induced Cracking Susceptibility In Steam Line Pipes And Weld Zones During Geothermal Well Construction, Riene Kaelamanda Pragitta, Yudha Pratesa

Journal of Materials Exploration and Findings

The susceptibility of steam line pipes, especially in the HAZ (heat-affected zone) and weldment areas, to hydrogen sulfide in the geothermal industry is crucial to understand from the early stages, particularly during construction. The combination of tensile stress from residual stresses after welding and metallurgical phase transformation makes the joint areas vulnerable to sulfide stress cracking. This condition becomes even more extreme when the equipment operates during the well stimulation phase. This research assesses the severity of H₂S-induced cracking using NACE MR0175 and ISO 15156-1 standards, focusing on the effects of pH and partial pressure of H₂S (p_{H₂S …}

Spin Coater Design With Pid Algorithm Using Polynomial Regression Approach And Bias Tuning For Tio2 Deposition Process, Geo Surya Andika, Nofrijon Sofyan, Donanta Dhaneswara, Akhmad Herman Yuwono

Journal of Materials Exploration and Findings

The thin-film deposition technique using spin coating offers a cost-effective alternative to Chemical Vapor Deposition (CVD) and Physical Vapor Deposition (PVD). The spin-coating process requires precise control of the motor drive system to ensure that the rotational speed, measured in rotations per minute (RPM), aligns with the set point and remains stable. This study presents the design and development of a spin coater prototype to achieve uniform thin-film deposition. The control method employed utilizes a Proportional-Integral-Derivative (PID) algorithm, incorporating a polynomial approach with bias tuning. The PID control was chosen to achieve stable operation in a non-linear system. The performance …

A Comparative Study Of Conventional And Statistically Active Corrosion Methods For Corrosion Growth Assessment Of A 24-Inch Gas Pipeline, Rudi Rinaldi, Jaka Fajar Fatriansyah

Journal of Materials Exploration and Findings

Component failures in oil and gas pipelines can have fatal consequences, leading to operational downtimes and environmental damage. Knowledge of the corrosion growth rate is fundamental to pipeline integrity management, as it is essential for risk assessment and decisions related to asset management. This article aimed to compare two approaches for the corrosion growth estimation of the 24-inch offshore gas pipeline: the conventional method versus the Statistically Active Corrosion (SAC) method. This article is based on the in-line inspection (ILI) results of two consecutive assessments from 2020 to 2023 of the entire 73 km of the pipeline. The results show …

Neural Operator And Physics-Informed Deep Learning Approaches For Inverse Design Of Composites And Manufacturing Processes, Minglei Lu

All Dissertations

In this dissertation, artificial intelligence (AI) models are designed and used to accelerate inverse design of composites and manufacturing processes. The critical bottlenecks in machine learning (ML) including data availability, data quality, model generalization and adaptation, interpretability, physical consistency, and the ’black box’ nature of models for the inverse design are addressed. And the proposed AI models are tested under different engineering scenarios. Firstly, a fast deep neural operator (DNO) structure was developed to significantly reduce training time. This model was tested in the context of additive manufacturing, a transformative industrial technology that allows for the creation of materials with …

Analysis Of Biomass Briquette Mixed Bagasse And Sugarcane Peel On The Performance Of Forced Top-Lit Updraft Gasifier Stove, Intan Hardiatama, Aron Enruico, Yuni Hermawan, Muhammad Trifiananto, Skriptyan N.H. Syuhri

Journal of Mechanical Engineering Science and Technology (JMEST)

The population growth in Indonesia from 270 million in 2020 to 279 million in 2024 has increased LPG consumption, potentially leading to future fuel shortages. The top-lit updraft (TLUD) gasifier stove using renewable biomass materials, offers a sustainable alternative. Biomass such as bagasse and sugarcane peel can be optimized into charcoal briquettes with high calorific value and low emissions. The calorific value of briquettes can be further enhanced by blending other high–calorific biomass materials. This experimental research focuses on testing the calorific value of raw bagasse and sugarcane peel before carbonization, as well as briquette mixtures (70:30, 50:50, 30:70) using …

Synthesis And In Vitro Testing Of Mg-6zn-Xhap Biocomposites From Beef Bone As Biodegradable Bone Implant Material, Jojor Lamsihar Manalu, Francisca Tjhay, Theodora Kristoforus, Sovian Aritonang

Journal of Mechanical Engineering Science and Technology (JMEST)

This study aimed to develop biodegradable Mg-6Zn hydroxyapatite (Mg-6Zn HAp) biocomposites for potential use in bone replacement applications. The hydroxyapatite (HAp) powders, sourced from cow bone, were synthesized through an eco-friendly and cost-effective process, leveraging bioresources for material sustainability. The Mg-6Zn and HAp powders were mechanically mixed through ball milling for six hours to ensure homogeneity. The resultant powder mixture was then subjected to isostatic pressing at a high pressure of 570 MPa, forming a dense coin-shaped composite with a 1.5 cm diameter. This coin was consolidated in a capsule furnace at elevated temperatures for one hour to enhance material …

Simulation-Based Methodology To Investigate The Impact Of Material Type And Compressive Speed Variation On Effective Strain Rate And Springback, Radhi Nurvian Amrullah, Syamsul Hadi, Muhammad Akhlis Rizza

Journal of Mechanical Engineering Science and Technology (JMEST)

To obtain the desired results in the manufacturing process, especially the bending process, the occurrence of springback must be reduced. The effective strain rate must be increased to predict the increase in material. This study uses a simulation method to determine the influence of material type and compressive speed variation on spring back and effective strain rate. This study uses 3 kinds of materials: JIS SPHD, JIS A1100 BE, and JIS SN400A, and speed variations, namely: 90 mm/s, 105 mm/s, and 120 mm/s. This study shows that JIS SN400A material has the smallest springback value compared to JIS A1100 BE …

Turbine Engine Reliability Analysis Using Reliability Availability Maintainability (Ram), Oyong Novareza, Zefry Darmawan, Nasir Widha Setyanto, Effendi Bin Mohamad

Journal of Mechanical Engineering Science and Technology (JMEST)

Electrical energy is a vital necessity characterized by ever-increasing electricity consumption. The most dominating power plant in Indonesia in supplying electricity is the steam power plant, which is 50%. In its implementation, there is damage that occurs where the highest damage is to the general unit with the highest damage to the turbine unit. Therefore, the author uses the reliability, availability, and maintainability method or RAM. The purpose of this study is to determine the value of RAM on the turbine system at PLN and provide recommendations for improvements to system performance. The results showed that the MTTF and MTTR …

Innovative Approaches For Improving Orc Performance: A Review Of Pure Fluids, Zeotropic Mixtures, And Nanoparticles, Ebenezer Kumi, Vasudevarao Veeredhi, Christopher Enweremad

Journal of Mechanical Engineering Science and Technology (JMEST)

Although the organic Rankine Cycle (ORC) is said to effectively capture low-grade heat, its commercialization has been limited because of working fluid constraints and inefficiencies resulting from operating at low temperatures. This study reviews the working fluids used in organic Rankine cycles and examines how nanoparticles could enhance the efficiency of the ORC, by enhancing the thermophysical properties of the working fluids. Results from this review showed that zeotropic mixtures of pure fluids, provide a viable approach to improving the thermophysical characteristics of organic working fluids and have the potential to achieve thermo-economic performance superior to that of individual pure …

Analysis Of Tidal Energy Potential In The Merauke Papua River Waters Indonesia, Peter Sahupala, Daniel Parenden

Journal of Mechanical Engineering Science and Technology (JMEST)

The purpose of this study is as a source of information to study the potential of tidal energy at the estuary of the Maro River in the waters of Merauke Regency. This study uses a quantitative method, while the method for determining the location of the study used is the purposive sampling method where the data collection point is right at the end of the estuary of the Maro River because it faces directly onto the Arafura Sea. Tide data for 5 months, namely September 1, 2023 to January 31, 2024 with a pool area of 1,260,000 m2, with the …

Innovations In Additive Manufacturing For Socket Fabrication: An Overview, Linda Ziyadatul Faiza, Wahyu Caesarendra, Wahyu Dwi Lestari

Journal of Mechanical Engineering Science and Technology (JMEST)

Additive Manufacturing (AM) has transformed the prosthetics industry, particularly in socket production, which plays a critical role in the comfort, fit, and functionality of prosthetic limbs. This article examines the latest advancements in AM technologies and their applications in socket fabrication. Key techniques like stereolithography (SLA), selective laser sintering (SLS), and fused deposition modeling (FDM) have facilitated the production of highly personalized, lightweight, and durable prosthetic sockets. These methods not only improve design precision but also allow for the use of biocompatible, flexible materials, enhancing both comfort and functionality. Digital design tools have streamlined the production process, reducing lead times …

Structural Simulation Of Wheelchair Ramp Using Finite Element Method, Bhre Wangsa Lenggana, Agung Nugroho, Ubaidillah Ubaidillah

Journal of Mechanical Engineering Science and Technology (JMEST)

Wheelchairs are essential mobility aids for people with disabilities, but they are often limited to flat surfaces and cannot overcome height differences. Portable ramps are an effective solution to overcome this limitation. This research aims to simulate and analyze the structure of a portable ramp for wheelchairs. Simulations were conducted using finite element method analysis software to assess the portable ramp's von Mises stress, deformation, and safety factor in various loading positions. Finite element method (FEM) analysis software was utilized to evaluate key mechanical properties, including von Mises stress, deformation, and safety factor, under different loading conditions and positions. The …

Study On Thermal-Fluid-Solid Coupling Characteristics For Helicopter Intermediate Spiral Bevel Gear Reducer, Dongping Sheng, Jie Yang, Chun Su

Journal of Mechanical Engineering Science and Technology (JMEST)

In the helicopter transmission system, the intermediate reducer is particularly special. It uses bevel gear pairs to change the transmission direction and to transfer the rotational speed effectively. Therefore, an in-depth study of the spiral gear pair is crucial to improve the overall performance of the helicopter rotor system. This study focuses on the study of the thermal-fluid-solid coupling characteristics and one-way steady-state thermal finite element analysis are conducted based on volume of fluid multiphase flow simulation theory to provide strong support for the design and optimization of the helicopter intermediate reducer. Several conclusions could be obtained. Firstly, it could …

The Potential Of Ramie Fiber As Reinforcement In Calcium Carbonate-Filled Polyester Resin Matrix Composites For Roofing Applications, Reinaldo Reinaldo, Djoko Setyanto

Journal of Mechanical Engineering Science and Technology (JMEST)

Polymer matrix composite roofing materials available in the Indonesian market typically consist of 30%wt chopped strand mat glass fiber embedded in unsaturated polyester resin, filled with 30 parts per hundred resin (PHR) calcium carbonate. The aim of this research is to evaluate whether natural ramie fibers can potentially replace glass fibers. In the first stage of the study, we compared three types of natural fibers abundant in Indonesia: banana stem fibers, sugarcane bagasse, and ramie. Showed that ramie fiber performed the best. Its flexural strength, flexural modulus, and impact toughness were the highest, measured at 191.57 MPa, 6691 MPa, and …

Characterization Of Hydroxyapatite Derived From Scallop Shell Waste Synthesized By Sonochemical Method With Different Temperature Calcination, Diki Dwi Pramono, Poppy Puspitasari, Aminnudin Aminnudin, Jeefferie Abd Razak

Journal of Mechanical Engineering Science and Technology (JMEST)

One common bio-ceramic material used in the biomedical industry is hydroxyapatite. Because of its crystallographic and molecular resemblance to the hard tissues of the human body, hydroxyapatite is thought to form. Scallop shells are one natural source of hydroxyapatite, which is high in calcium. This study examines how the calcination temperature affects the characteristics of hydroxyapatite made from leftover scallop shell. Hydroxyapatite was synthesized via the sonochemical method, with calcination conducted at temperatures of 900°C, 1000°C, and 1100°C. The hydroxyapatite that was prepared was assessed using Xray diffraction (XRD) to determine the phase and crystallite size, Scanning Electron Microscopy (SEM) …

The Role Of Banana Peel Surface Pores Through Increasing Temperature For Efficient Hydrogen Production, Abid Fahreza Alphanoda, Erlanda Augupta Pane, Agus Riyanto, Avita Ayu Permanasari

Journal of Mechanical Engineering Science and Technology (JMEST)

Porous carbon derived from banana peel has been synthesized by increasing the temperature range variation from 180 oC - 270 oC. The prepared carbon was tested in an experiment using double-chamber photoelectrochemistry to see the results of hydrogen production. SEM-EDX, FTIR, and TGA analyses identified all banana peel carbons. Optical and electrochemical properties were analyzed and measured by UV-Vis, Tauc Relationship, and Pearson Absolute Electronegativity. The amount of hydrogen gas produced from the simulation of UV-A visible light irradiation on variations of BP-240, BP-210, BP-180, and BPNatural. The surface of BP-270 has more pores and can produce the most significant …

Impact Of Natural Polymer Proportions On The Fire-Retardant Properties Of Bioplastics, I Gusti Ngurah Nitya Santhiarsa, Ni Made Dwidiani, I Gusti Ngurah Putu Tenaya, I Gede Artha Negara

Journal of Mechanical Engineering Science and Technology (JMEST)

This research investigates the influence of varying proportions of natural polymers on the fire-retardant properties of bioplastic. Tapioca starch (Manihot esculenta) and corn starch (Zea mays) were selected as the bioplastic materials, with different weight fractions employed in the analysis. These materials, as naturally occurring polymers, are biodegradable and serve as promising components in the development of bioplastics. Fire resistance testing was conducted in accordance with ASTM D635-03, utilizing weight ratios of tapioca to corn starch at 70:30, 60:40, and 50:50. The results included photographic documentation of each specimen alongside the corresponding outcomes from the fire resistance tests. These images …

Analysis Of Titanium Mesh Ti6al4v Formation Using Die Press Forming Machine For Cranioplasty, Ahmad Ayyub Syaiful Rizal, Mahros Darsin, Robertoes Koekoeh K. Wibowo, Khairul Anam

Journal of Mechanical Engineering Science and Technology (JMEST)

Cranioplasty is required for patients with head defects, where the deformed part of the head is replaced with Ti6Al4V titanium wire implants. The titanium wire forming process is usually done manually, which can take a long time and give results that do not match the anatomical shape of the head. Therefore, it is important to develop domestic technology that can produce titanium wire automatically. This study aims to analyze the frame and mold of the automatic wire mesh molding machine before production. The tool is made using press forming method and finite element analysis with ANSYS software. The machine frame …

Characteristics Of Liquid Products From Spirulina Platensis Pyrolysis Under Microwave Irradiation With Activated Carbon Additive, Mohammad Mirza Yuniar Romaz, Sukarni Sukarni, Retno Wulandari

Journal of Mechanical Engineering Science and Technology (JMEST)

Global energy consumption has surged due to the population's rapid growth, leading to a switch to using renewable and clean energy. Among various strategies for developing renewable and clean energy, biomass pyrolysis emerged as attractive, and microwave irradiation pyrolysis is a prominent technique. This research aims to determine the ideal parameters for microwave-assisted pyrolysis of Spirulina platensis (SP) microalgae in order to produce high-value liquid products with the addition of activated carbon (AC) additives. Liquid bio-oil products were characterized concerning their calorific value, chemical bonds, and thermal stability. This research also investigates product distribution as a function of AC loading. …

Friction Modeling Of Composite Brake Pads With Ulin Wood Powder (Eusideroxylon Zwageri), Muhammad Rezki Fitri Putra, Hajar Isworo, Muhamad Noor Yasin, Rachmat Subagyo

Journal of Mechanical Engineering Science and Technology (JMEST)

This study investigates the performance of composite brake pads made of Ulin (Eusideroxylon zwageri) sawdust using simulation modeling, focusing on the pressure distribution, frictional stress, and contact state in five brake pad designs (DS0 to DS4). The brake pad designs used U-shaped grooves to improve cooling efficiency and debris removal. The results show that DS1 and DS2 exhibit the most uniform pressure distribution, with maximum values of 0.045 MPa and 0.048 MPa, respectively. DS1 recorded the highest peak frictional stress at 2.53 × 10-8 MPa, while DS2 showed consistent stress stability, reducing the possibility of uneven wear. DS3 achieved a …

Characterization And Performance Nanofiltration Membranes In Water Quality For Goldfish (Carassius Auratus) Aquaculture, Inpita Casuarina Eqisetia Utari, Uun Yanuhar, Asus Maizar Suryanto Hertika, Heru Suryanto, Jibril Maulana, Nico Rahman Caesar, Mahrus Ismail, Leong-Seng Lim

Journal of Mechanical Engineering Science and Technology (JMEST)

Water quality is an important factor in aquaculture activities, including goldfish (Carassius auratus) farming. One approach to improving water quality is the use of nanofilters. This study aims to evaluate the performance of nanofilters made from Sargassum sp. with the addition of copper oxide nanoparticles. The method used involves the fermentation of bacterial cellulose from Acetobacter xylinum using Sargassum sp. extract as a medium, followed by homogenization and the addition of CuO-NPs at concentrations of 0.5%, 1%, and 1.5%, and subsequent oven drying. The nanofilter membrane will then be analyzed using SEM, XRD, and FTIR to characterize its properties. Performance …

Captivating Combustion Traits Of Bio-Oil Droplets Enriched With Bio-Additives From The Areca Shell Waste, Muhammad Alif Raehan, Helen Riupassa, Hendry Y. Nanlohy

Journal of Mechanical Engineering Science and Technology (JMEST)

Fuel derived from crude vegetable oil, such as coconut oil, holds promise as an alternative energy source to mitigate the increasing reliance on fossil fuels driven by population growth and industrial activities. The experiment involved suspending a single droplet of crude coconut oil mixed with activated carbon from areca shell waste and placed at the junction on R-type thermocouple (Pt/Pt-Rh13%). The droplets were ignited using a hot wire and subjected to atmospheric pressure and room temperature. Coconut oil comprises a saturated triglyceride carbon chain compound of approximately 91%, and areca shell waste possesses a porous structure that fosters favorable interactions …

The Effect Of Mixing Time And Rotation Speed On The Consistency Of Dough Viscosity In A Horizontal Mixer, Muhammad Akhlis Rizza, Ekky Yovianto Dharsono, Anggit Murdani, Ratna Monasari, Radhi Nurvian Amrullah, Supa Kusuma Aji, Dian Noorvy Khaerudin

Journal of Mechanical Engineering Science and Technology (JMEST)

Cassava must go through several manufacturing processes before it becomes chips on the market, including the process of stirring the dough. The stirring process is an important stage in various food industries. In the stirring process, the viscosity change in the dough is influenced by various factors, including the stirring process time and speed in stirring. Research on dough viscosity is important because it is directly related to the quality of the final product. The purpose of this study is to provide recommendations to users, both in the context of using horizontal mixers and the process of making similar products. …

Optimization Of The Number Of Cylinder Blades In Coffee Pulper Machine: Finite Element Analysis And Simple Additive Weighting Methods, Mochamad Rifki Syahriza, Dwi Djumhariyanto, Nasrul Ilminnafik, Mahros Darsin, Danang Yudistiro, Hari Arbiantara Basuki, Robertoes Koekoeh Koentjoro Wibowo, Ahmad Syuhri, Sumarji Sumarji

Journal of Mechanical Engineering Science and Technology (JMEST)

The increasing interest in coffee in all circles means that coffee production and quality must always increase due to consumer demands. One way to maintain the quality of coffee beans is by breaking them down using a huller machine. This research aims to improve the optimization of coffee machines by modifying the cylinder blades of huller machines with variations of 3, 4, 5, and 7 cylinder blades in terms of static loading design and quality and production capacity of coffee bean breaking. The experiment was carried out using 400 rpm and breaking 10kg of dry coffee cherries every time the …

Tactical Activities To Improve The Effectiveness Of Concrete Batching Plant Based On Overall Equipment Effectiveness Analysis, Yurida Ekawati, Iddo Christian Sutrisno, Teguh Oktiarso

Journal of Mechanical Engineering Science and Technology (JMEST)

The growth of infrastructure projects has led to an increased demand for ready-mix concrete. A company that produces ready-mix concrete using a batching plant encountered difficulties in fulfilling customer orders due to the high rate of machine downtime. Overall equipment effectiveness (OEE) was employed to examine these issues at the tactical activities, where the root causes of losses that occur in the OEE components of availability, performance, and quality were addressed. The OEE analysis was extended to encompass maintenance effectiveness measures, as the anticipated solution to the problem was not the replacement of the machine, but rather an enhancement of …

The Influence Of Sodium Chloride Treatment On The Sisal Fiber Bundle’S Properties, Tamaryska Setyayunita, Heru Suryanto, Aminnudin Aminnudin

Journal of Mechanical Engineering Science and Technology (JMEST)

Currently, composite board manufacturing using natural fiber has the potential to be expanded due to environmental awareness. To produce high-performance natural fiber, treatment is needed to improve natural fiber’s mechanical and physical properties. One of chemical treatments is by using sodium chloride (NaCl). This study aimed to investigate the characteristics of sisal fiber after NaCl treatment. The concentrations of NaCl treatment were 1, 3, and 5 (wt.%) at room and boiling temperature and the soaking duration was 1 hour. Meanwhile, tensile strength, strain, and Young’s modulus were tested to evaluate the mechanical properties. Fiber bundle diameter, weight change due to …

Development Of Machine Learning-Based Tool For Prediction Of Long-Term Field Performance Of Asphalt Concrete Overlays In A Hot And Humid Climate, Elise Mansour

LSU Doctoral Dissertations

The performance of pavement plays a critical role in Maintenance, Rehabilitation and Reconstruction (MR&R) for highway agencies. Reliable and accurate estimation of pavement performance can be instrumental in prioritization of the limited resources and funding for highway agencies. The latter requires robust prediction models that can handle large-scale, real-world data and can forecast pavement performance in the long run. Unfortunately, the traditional performance prediction models have raised concerns regarding their efficiency and accuracy. It is because these models were based on a limited number of explanatory variables, were not up-to-date and were designed for forecasting short-term (up to five years) …