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All Journal International Journal of Electrical and Computer Engineering IAES International Journal of Artificial Intelligence (IJ-AI) Media Statistika Jurnal Ilmiah Teknologi dan Rekayasa ELKHA : Jurnal Teknik Elektro Jurnal Teknologi Rekayasa Mesin Media Mesin: Majalah Teknik Mesin Jurnal Rekayasa Mesin Turbo : Jurnal Program Studi Teknik Mesin Journal of Energy, Mechanical, Material and Manufacturing Engineering JTERA (Jurnal Teknologi Rekayasa) Angkasa: Jurnal Ilmiah Bidang Teknologi Jurnal Kreativitas PKM TELKA - Telekomunikasi, Elektronika, Komputasi dan Kontrol Jurnal Muara Sains, Teknologi, Kedokteran dan Ilmu Kesehatan Infotekmesin Jurnal Asiimetrik: Jurnal Ilmiah Rekayasa Dan Inovasi Journal of Applied Sciences and Advanced Technology International Journal of Marine Engineering Innovation and Research Jurnal Bakti Masyarakat Indonesia Teknosains : Jurnal Sains,Teknologi dan Informatika jurnal syntax admiration Madaniya Journal of Community Development Logic : Jurnal Rancang Bangun Dan Teknologi Jurnal INFOTEL Jurnal Keamanan Nasional ABDIKOM Jurnal Polimesin
James Julian
Department Of Mechanical Engineering, Faculty Of Engineering, Universitas Pembangunan Nasional Veteran Jakarta
Religion Aerospace Engineering Agriculture, Biological Sciences & Forestry Humanities Automotive Engineering Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Civil Engineering, Building, Construction & Architecture Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Education Electrical & Electronics Engineering Energy Engineering Environmental Science Health Professions Industrial & Manufacturing Engineering Languange, Linguistic, Communication & Media Law, Crime, Criminology & Criminal Justice Library & Information Science Materials Science & Nanotechnology Mathematics Mechanical Engineering Medicine & Pharmacology Nursing Physics Public Health Social Sciences Transportation Other

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Study of hydrodynamic characteristics in oscillating wave surge converter julian, james; Anggara, Rizki Aldi; Naufal, Ridwan Daris; Ramadhani, Rifqi; Prasetyo, Eko Andi; Wahyuni, Fitri; Gunasti, Nabilah Dwi
Jurnal Polimesin Vol 22, No 2 (2024): April
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/jpl.v22i2.4715

Abstract

In the realm of renewable energy, researchers worldwide have been paying close attention to developing the Oscillating Wave Surge Converter (OWSC) device. This device has the potential to harness the power of ocean waves and convert it into a reliable source of clean energy. Hydrodynamic characteristics are essential parameters in developing OWSC devices. Therefore, this research conducted a hydrodynamic study on the OWSC device with variations in ocean wave periods, including T= 1.5, 1.7, 1.9, 2.1, and 2.3. The Boundary Element Method (BEM) describes the interaction between sea waves and floating body structures. This method assumes incompressible, inviscid, and irrotational flow. A numerical approach is used as a calculation method followed by verification and validation to support the level of actualization. The research results showed that the incident wave caused the OWSC device to experience a deviation from its equilibrium position in the form of an oscillating flap inclination angle as a form of hydrodynamic characteristics. The sea wave period correlatedwith the rate of change in flap position over time, including the maximum deviation in the flap angle. As a power plant, the performance of the OWSC device can work at reasonably short-wave period intervals based on the device's ability to produce mechanical power. The highest average mechanical power was achieved in the T= 1.5 period of 34.49 Watts with an efficiency of up to 52.43%. The OWSC device requires a high intensity of wave energy in a short duration to generate optimal mechanical power. It is important to note that optimal mechanical power generation is crucial for the OWSC device to function effectively. Therefore, the device should be placed in a location where the wave energy intensity is consistently high.
Numerical Study On Characteristics Of The Backward-Facing Step Flow With Variations Of The Slope Angle Of The Step julian, james; Anggara, Rizki Aldi; Wahyuni, Fitri
Jurnal Polimesin Vol 22, No 1 (2024): February
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/jpl.v22i1.4052

Abstract

The phenomenon of flow separation plays a vital role in the industrial world. The backward-facing step (BFS) is a general form representing flow separation. This study investigates the influence of the slope angle of the step on BFS flow characteristics at various low Reynolds numbers. According to the CFD results, the flow separation phenomenon forms a circulation zone for each increase in Reynolds numbers. This phenomenon is a result of the sudden expansion of the channel geometry. The BFS with the slope angle of the step demonstrates that the increase in the recirculation zone can be minimized, thus appropriately delaying flow separation. The recirculation zone causes fluid flow to reverse direction, affecting fluid flow efficiency due to resulting pressure differences. Therefore, a BFS with the slope angle of the step exhibits a more efficient flow phenomenon by minimizing the recirculation zone.
Analisis Daya Keluaran pada Kinerja Motor Listrik Tipe Synchronous Berbasis Komputasional Ferdyanto, Ferdyanto; Farha, Auditya; Julian, James; Wahyuni, Fitri; Rizal, Reda
TELKA - Telekomunikasi Elektronika Komputasi dan Kontrol Vol 9, No 2 (2023): TELKA
Publisher : Jurusan Teknik Elektro UIN Sunan Gunung Djati Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15575/telka.v9n2.107-116

Abstract

Masalah yang menjadi pertimbangan dalam penggunaan motor listrik adalah daya keluaran yang dihasilkan pada saat motor bekerja. Penelitian ini berfokus pada analisis daya keluaran Permanent Magnet Synchronous Motor (PMSM) yang akan diuji pada kecepatan tertentu serta ditinjau terhadap perubahan sudut torsi tiap putaran. Tujuan penelitian ini adalah mendapatkan analisis daya keluaran dengan karakteristik yang stabil serta kinerja PMSM yang menghasilkan efisiensi sesuai standar. Penelitian menggunakan metode komputasi dengan model finite element analysis (FEA) yang dilakukan dengan menggunakan software. Hasil dari penelitian ini diperoleh performa PMSM dengan arus input sebesar 1.5 kA pada setiap fasa sehingga motor dapat beroperasi dengan kecepatan 13300 rpm serta menghasilkan torsi sebesar 164 Nm. Fluks magnet yang terbentuk berada dalam kondisi stabil dengan nilai 0.02 Wb dan membentuk distribusi medan magnet yang merata pada setiap kumparan stator. Rata-rata daya keluaran maksimum yang dihasilkan jangkar rotor adalah 107.6 kW pada sudut torsi 114°. Penelitian telah berhasil memperoleh analisis daya keluaran pada PMSM melalui metode komputasi. Hasil analisis tersebut dapat menjadi acuan dalam proses manufaktur PMSM. The problem that is considered in the use of electric motors is the output power generated when the motor is working. This research focuses on analyzing the output power of a Permanent Magnet Synchronous Motor (PMSM) which will be tested at a certain speed and looking at changes in torque angle for each rotation. The aim of this research is to obtain an output power analysis with stable characteristics and PMSM performance that produces efficiency according to standards. The research uses computational methods with finite element analysis (FEA) models which are carried out using software. The results of this research obtained PMSM performance with an input current of 1.5 kA in each phase so that the motor can operate at a speed of 13300 rpm and produce a torque of 164 Nm. The magnetic flux formed is in a stable condition with a value of 0.02 Wb and forms an even magnetic field distribution in each stator coil. The average maximum output power produced by the rotor armature is 107.6 kW at a torque angle of 114°. Research has succeeded in obtaining output power analysis on PMSM through computational methods. The results of this analysis can be used as a reference in the PMSM manufacturing process.
Thermal Performance of a Branching-Channel Liquid Cooling System for Cylindrical Li-Ion 18650 Batteries Anggie Topan Wijaya; James Julian; Fitri Wahyuni; Riki Purba; Fathin Madhudhu; Elvi Ermadani; Adi Winarta
Logic : Jurnal Rancang Bangun dan Teknologi Vol. 25 No. 3 (2025): November
Publisher : Unit Publikasi Ilmiah, P3M, Politeknik Negeri Bali

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31940/logic.v25i3.210-218

Abstract

Lithium-ion batteries need effective thermal management to avoid safety risks like thermal runaway. This study analyzes and optimizes a liquid cooling system. Battery Thermal Management System (BTMS) using a branching mini-channel cold plate design for eight Li-ion 18650 batteries. A Computational Fluid Dynamics model was developed to simulate performance at a 2C discharge rate with configurations of 3 (N3), 5 (N5), and 7 (N7) branches. The results, validated against experimental data, showed that all configurations kept maximum temperatures below 37°C and maintained temperature uniformity (ΔT) below 5°C. Increasing branches reduced pressure drop, with the N7 design showing the lowest ΔP of 5.16 Pa. Although it had a lower heat transfer coefficient, N7 achieved the highest J/F factor, indicating optimal thermo-hydraulic performance for liquid-cooled battery systems.
Comprehensive Analysis on the Influence of Flap Width on the Hydrodynamic Parameters of OWSC Devices Rasya Aulia Nathania Nisa; James Julian; Fitri Wahyuni; Riki Hendra Purba; Fathin Muhammad Mahdhudhu; Elvi Armadani
Logic : Jurnal Rancang Bangun dan Teknologi Vol. 25 No. 3 (2025): November
Publisher : Unit Publikasi Ilmiah, P3M, Politeknik Negeri Bali

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31940/logic.v25i3.201-209

Abstract

The growing need for renewable energy has driven significant interest in harnessing ocean wave power, particularly through Oscillating Wave Surge Converters (OWSCs). This study focuses on examining the effect of flap width on the hydrodynamic capacity of an OWSC, as flap geometry plays a crucial role in energy capture efficiency. A numerical methodology utilizing the Boundary Element Method (BEM) was employed to assess hydrodynamic parameters across both temporal and frequency domains. Five flap width variations were tested under regular wave conditions with different periods, while mesh independence and validation against experimental data ensured accuracy. The results in the time domain revealed a direct correlation between flap width and angular deviation, velocity, torque, and power output, although wider flaps exhibited less stability due to increased inertia. Frequency domain analysis indicated that each flap width had a distinct resonant peak, with narrower flaps performing best at shorter periods and wider flaps at longer ones. Notably, moderately sized flaps (W2 and W3) achieved the highest efficiency, with Capture Width Ratios exceeding 70%, outperforming wider flaps despite their larger surface area. These findings highlight the importance of optimized flap width for efficient and reliable OWSC design.
Numerical investigation of heat reduction system in 42110 Lithium-Ion battery packs using cooling plate spacing variations Adhitama, Bima Rakha; Julian, James; Wahyuni, Fitri; Madhudhu, Fathin Muhammad; Armadani, Elvi
Jurnal Polimesin Vol 23, No 6 (2025): December
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/jpl.v23i6.7692

Abstract

An efficient thermal reduction system is crucial for ensuring the optimal performance and safety of Electric Vehicle (EV) batteries, notably by maintaining uniform temperature distribution and minimizing the risk of thermal runaway. This study presents a numerical investigation of the thermal behaviour of a liquid-cooled system for a cylindrical Li-ion 42110 battery pack, focusing on the influence of varying cold-plate spacing. Three cold plate configurations with spacing ratios r = 0.78, r = 0.33, and r = 0 were examined, with r = 0.78 corresponding to the most significant separation. The simulation employed a Reynolds-Averaged Navier–Stokes (RANS) model to resolve fluid flow and energy transport, and the heat-generation profile was derived from experimental data. The results show that all cooling configurations substantially reduced the maximum temperature relative to the uncooled case, with the widest spacing (r = 0.78) achieving the most significant average reduction of 19.736%. However, designs with smaller spacing exhibited slightly higher temperatures and reduced uniformity, particularly near the positive pole, where heat concentration is more pronounced. The temperature deviation remained within the acceptable 2% threshold. These findings highlight not only the thermal effectiveness of each spacing ratio but also its design implications, demonstrating that spacing plays a critical role in controlling peak temperature and maintaining uniformity. Overall, the study emphasizes that strategic cold-plate spacing is essential for reliable, efficient, and thermally stable battery operation in EV applications.
The effect of flap thickness on the hydrodynamic performance of an oscillating wave surge converter Julian, James; Nisa, Rasya Aulia Nathania; Wahyuni, Fitri; Purba, Riki Hendra; Madhudhu, Fathin Muhammad; Armadani, Elvi
Jurnal Polimesin Vol 23, No 6 (2025): December
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/jpl.v23i6.7682

Abstract

With the growing demand for energy and the need to transition to renewable sources, ocean wave energy presents great potential. The Oscillating Wave Surge Converter (OWSC) is a promising technology due to its nearshore applicability, structural simplicity, and robust design. This study systematically investigates the effect of flap thickness on the dynamic performance of a hinge-mounted OWSC using the Boundary Element Method (BEM).   The research models the hydrodynamic interactions and analyzes the effects of three different flap thicknesses on key metrics, including maximum angle deviation, angular velocity, torque, and power capture. The results indicate that all flap variations demonstrate stable oscillatory movement, but greater flap thickness reduces the maximum angle deviation due to increased inertia and hydrostatic pressure. A resonant peak was observed for all thicknesses at a wave period of 1.3 seconds, where energy transfer was maximized. At this frequency, the thickest flap achieved the highest efficiency (78.94%), followed by the intermediate (77.50%) and thinnest (70.77%) variations. The findings suggest that while flap thickness influences efficiency, the primary factor for maximizing energy capture is the alignment of the wave period with the device's natural frequency.
THE EFFECT OF OFFSET RATIO ON OFFSET JET FLOW STRUCTURE Ramadhani, Rifqi; Julian, James; Wahyuni, Fitri; Purba, Riki Hendra; Madhudhu, Fathin Muhammad; Armadani, Elvi
TURBO [Tulisan Riset Berbasis Online] Vol 14, No 2 (2025): TURBO: Jurnal Program Studi Teknik Mesin
Publisher : Universitas Muhammadiyah Metro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24127/trb.v14i2.4538

Abstract

Jet flow is a crucial fluid dynamic phenomenon that has been extensively studied. It is essential for various industrial applications, including surface cleaning, flow control, and cooling electronic components.  Offset jet is an innovation in jet flow configuration that offers advantages in flow pattern control by expanding the impingement area and regulating surface pressure distribution. This study employed a Computational Fluid Dynamics (CFD) approach to investigate the influence of variations in the offset jet ratio on the aerodynamic characteristics of the flow, specifically the impingement zone area, pressure coefficient distribution, and skin friction coefficient. The standard k-ε turbulence model, utilizing a structured mesh and a Reynolds number of 10,000, was employed in this research. The number of mesh elements used was a fine mesh of 200,000 with an error percentage of 0.09436%. The results of the study show that an offset ratio of 3 produces the highest cf value of 0.0047 and a stable Cp distribution of 0.218, while also providing the best impingement zone area. These findings indicate that OR 3 is the most optimal configuration in terms of aerodynamics for precision system applications, with a focus on flow pattern control and wide impingement zone coverage.
Investigation of the Influence of Plate Thickness on Orifice Flow Using the Computational Fluid Dynamics Method Rivai, Mokhammad Bahtiar; Julian, James; Wahyuni, Fitri; Purba, Riki Hendra
TURBO [Tulisan Riset Berbasis Online] Vol 14, No 2 (2025): TURBO: Jurnal Program Studi Teknik Mesin
Publisher : Universitas Muhammadiyah Metro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24127/trb.v14i2.4286

Abstract

Piping systems provide effective fluid distribution and are crucial to industrial operations. Despite their effectiveness, flow control devices like orifice plates can result in significant pressure drop that can lower system efficiency and wear out the system’s mechanical components. This study aims to optimize orifice plate design by examining the effect of plate thickness on flow characteristics using Computational Fluid Dynamics (CFD). Simulations were conducted on orifice plates with thicknesses ranging from 1.5T to 3.0T under Reynolds numbers from 10⁴ to 10⁶. Results show that increasing the thickness reduces pressure loss, with the 3T configuration achieving a 1.35% reduction compared to the baseline. Improvements are linked to a higher discharge coefficient (Cd), shorter flow reattachment distance (Xr), smaller recirculation zones, and reduced velocity through the orifice throat. These findings suggest that geometric modifications can enhance flow performance and reduce the risk of mechanical damage in piping systems.
Performance Evaluation of Liquid Cooling Systems in 18650 Batteries: A Case Study of Mass Flow Rate Variations in Mini-Channel Cold Plates Fourlando, Rainer Samuel; Julian, James; Topan, Anggie Wijaya; Purba, Riki Hendra; Madhudhu, Fathin Muhammad; Armadani, Elvi Wijaya; Wahyuni, Fitri
JTERA (Jurnal Teknologi Rekayasa) Vol 10, No 2: Desember 2025
Publisher : Politeknik Sukabumi

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Pengelolaan energi termal yang esensial sangat penting bagi performa optimal, keamanan, dan umur pakai baterai lithium-ion (Li-ion), yang menghasilkan panas cukup besar selama operasi. Suhu berlebih dapat menyebabkan degradasi kapasitas dan thermal runaway. Studi ini secara numerik menyelidiki kinerja termal dari sistem pendingin cair yang menggunakan mini-channel cold plate untuk sebuah modul yang terdiri dari delapan baterai Li-ion tipe 18650. Tujuan utama penelitian ini adalah mengevaluasi pengaruh variasi laju alir massa pendingin (air) terhadap temperatur maksimum baterai (TMAX) dan keseragaman temperatur (ΔT). Model computational fluid dynamics (CFD) yang telah divalidasi dengan data eksperimen digunakan dalam analisis ini. Tiga variasi laju alir massa disimulasikan, yaitu 0,0005 kg/s, 0,0015 kg/s, dan 0,0025 kg/s. Hasilnya menunjukkan bahwa sistem yang diusulkan memiliki efisiensi tinggi, mampu menjaga TMAX baterai di bawah 26,5 °C pada semua konfigurasi, dengan penurunan lebih dari 49% dibandingkan kondisi tanpa pendinginan, di mana suhu mencapai 52 °C. Laju alir massa tertinggi (0,0025 kg/s) memberikan kinerja terbaik, dengan TMAX terendah sebesar 25,83 °C serta rata-rata penurunan temperatur tertinggi sebesar 50,5%. Selain itu, konfigurasi ini juga memberikan keseragaman termal yang lebih baik dan berhasil menjaga perbedaan temperatur internal setiap sel tetap di bawah ambang kritis 5 °C. Temperatur maksimum yang dicapai dengan sistem pendingin cair ini menunjukkan bahwa sistem tidak hanya mampu mencegah thermal runaway tetapi juga berkontribusi dalam memperpanjang siklus hidup dan daya tahan baterai. Sistem pendingin ini membantu meminimalkan mekanisme degradasi termal yang umumnya mempercepat penuaan baterai.
Co-Authors Achmad Zuchriadi Ade Fikri Fauzi Adhitama, Bima Rakha Adi Winarta, Adi Akmal, Reza Najmi Aldi Anggara, Rizki Anggara, Rizki Aldi Anggie Topan Wijaya Annastya Bagas Dewantara Anton Prabowo Armadani, Elvi Wijaya Armansyah Armansyah Armansyah Armansyah Armansyah Bagas Dewantara, Annastya Billad, Rayhan Fariansyah Budiarso Budiarso, Budiarso Bunga, Nely Toding Demo Putra Demo Putra Desta Sandya Prasvita Dewantara, Annastya Bagas Dwi Yulia Handayani Elvi Armadani Elvi Armadani Elvi Ermadani Ermadani, Elvi Faiz Daffa Ulhaq Farha, Auditya Fathin Madhudhu Fathin Muhammad Mahdhudhu Fauzi, Ade Fikri Ferdyanto Ferdyanto, Ferdyanto Firdaus, Talitha Fatiha Fitri Wahyuni Fitri Wahyuni Fitri Wahyuni Fitri Wahyuni Fourlando, Rainer Samuel Gunasti, Nabilah Dwi Hadinata, Tri Hapidzha, Putty Harinaldi . I Wayan Marlon Managi I Wayan, Marlon Managi Idris Marbawi Iskandar, Waridho Junaedi, Thomas Juri Saedon Kasih Prihantoro Lomo Mula Tua Lumbantoruan, Regina Lumbantoruan, Regina Natalindah Madhudhu, Fathin Muhammad Mahdhudhu, Fathin Muhammad Marbawi, Idris Miftahul Jannah Mirza Fauzan Lukiano Mufti Ahmad Fadilah Nandy Putra Naufal, Ridwan Daris Nisa, Rasya Aulia Nathania Nisa, Raysa Oktavia, Nana Triana Parker Stefan, Parker Patrick, Juan Prabowo, Anton Dwi Prakoso, Lukman Yudho Prasetyo, Eko Andi Purba, Riki Hendra Putty Fauthyda Zahra Hapidzha Ramadhani, Rifqi Rasya Aulia Nathania Nisa Reda Rizal Revan Difitro, Revan Ridwan Daris Naufal Rifqi Ramadhani Riki Hendra Purba Riki Purba Rivai, Mokhammad Bahtiar Rizki Aldi Anggara Rizki Aldi Anggara Rizki Anggara, Rizki Rudy Sutanto Saphira Anggraita Siswanto Sari, Rena Satria, Muhammad Fari Sedeq, Khalees Siswanto, Saphira Anggraita Toding Bunga, Nely Topan, Anggie Wijaya Tri Hadinata Tua, Lomo Mula Tulus Hidayat Yusanto Ulfa Hanifah Nurhaliza Ulhaq, Faiz Daffa Waridho Iskandar Waridho Iskandar Yuliana, Sekar Zackharia Rialmi