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All Journal Jurnal Asiimetrik: Jurnal Ilmiah Rekayasa Dan Inovasi Jurnal Mekanik Terapan
Bunga, Nely Toding
Universitas Pancasila
Automotive Engineering Civil Engineering, Building, Construction & Architecture Computer Science & IT Electrical & Electronics Engineering Energy Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mechanical Engineering

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Numerical Analysis of Gurney Flap Impact on NACA 4415 Airfoil Aerodynamics Performance James Julian; Mirza Fauzan Lukiano; Fitri Wahyuni; Waridho Iskandar; Nely Toding Bunga
Jurnal Asiimetrik: Jurnal Ilmiah Rekayasa dan Inovasi Volume 6 Nomor 1 Tahun 2024
Publisher : Fakultas Teknik Universitas Pancasila

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35814/asiimetrik.v6i1.5722

Abstract

Improving airfoil aerodynamic performance is an essential aspect of aerodynamic technology. The use of passive flow control is one way to enhance the aerodynamic performance of the airfoil. The influence of using gurney flaps as passive flow control was explored through the CFD approach employing the RANS control equations with the k-epsilon turbulence model. The airfoil model utilized in this investigation was the NACA 4415 operating at a Reynolds number of 1×106. This study explored three different variations of flap height, namely 0.5%, 1%, and 2% of chord length. The outcomes showed that adding gurney flaps showed quite positive results in increasing the lift and drag performance of NACA 4415. An airfoil with a 0.5%c height flap has an average percentage increase in Cl of 12%, followed by a height flap of 1%c, which is 23%, and a percentage Cl of 37% for a height flap of 2%c. Meanwhile, each variation in height flap affected the increase in Cd. A height flap of 0.5%c increased Cd with an average percentage of 2%, while a height flap of 1%c increased the percentage of Cd by 4% and 6% for a height flap of 2%c. Moreover, visualization of fluid flow with pressure and velocity contours given at AoA 12º to determine the effect on the increase in Cland Cd in NACA 4415.
Numerical Modelling of NACA 0015 Airfoil Under the Erosion Condition Rayhan Fariansyah Billad; James Julian; Fitri Wahyuni; Waridho Iskandar; Nely Toding Bunga
Jurnal Asiimetrik: Jurnal Ilmiah Rekayasa dan Inovasi Volume 6 Nomor 1 Tahun 2024
Publisher : Fakultas Teknik Universitas Pancasila

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35814/asiimetrik.v6i1.5875

Abstract

Airfoil that experiences erosion caused by flying debris that hit the airfoil can affect the performance of the airfoil. This research was studied to determine the effect of erosion with varying erosion length using numerical methods on the performance of the NACA 0015 airfoil. This research was simulated using the Computational Fluid Dynamics (CFD) approach. Reynolds Averaged Navier-Stokes (RANS) is implemented as the governing equation. The turbulence model used in this research is the k-epsilon model. The Reynolds number used is 1.5 x 10⁶. This research proves that the erosion effect can reduce the Cl value and increase the Cd value on the NACA 0015 airfoil. Increasing the erosion length on the airfoil can also affect the Cl value and Cd value, but this effect is insignificant. In the contour visualization, it can be seen that the airfoil that is experiencing erosion has a pressure contour that increases in the upper chamber and decreases in the lower chamber compared to the airfoil that does not experience erosion so that it can reduce the lifting force of the NACA 0015 airfoil. The flow velocity and streamline contours also show greater circulation in the erosion airfoil, which can accelerate the stall by 1o AoA. Then, variations in increasing erosion length on the airfoil do not show any significant differences in pressure contours or circulating flow.
Investigation of Flap Dimensional Parameters to Improve Hydrodynamic Performance of Oscillating Wave Surge Converter Device Rizki Aldi Anggara; James Julian; Fitri Wahyuni; Riki Hendra Purba; Nely Toding Bunga
Jurnal Asiimetrik: Jurnal Ilmiah Rekayasa Dan Inovasi Volume 7 Number 1 (2025)
Publisher : Fakultas Teknik Universitas Pancasila

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35814/asiimetrik.v7i1.7911

Abstract

Renewable energy transition is a strategic step in overcoming environmental damage due to fossil fuel exploitation. Ocean wave energy comes with its popularity, considering its advantages in supplying energy continuously and having high energy density. Therefore, technology that can extract other wave energy effectively and efficiently is needed. This study focuses on identification flap geometry to improve the oscillating wave surge converter (OWSC) hydrodynamic performance. Through a numerical approach, the Boundary Element Method (BEM) is applied in three-dimensional flap modeling to accommodate testing the characteristics and performance of the OWSC device. This study identified five different samples: geometry 1, geometry 2, geometry 3, geometry 4, and geometry 5. The results show that the second geometry variation is the most optimal flap dimension parameter. The best proportion is found in the dimensional characteristics parallel to the elevation of the ocean waves to maximize the output torque. Overall, the second geometry performs satisfactorily with an average maximum power achievement of 41.52 Watts at a wave period of T = 1.5s. In addition, the OWSC device with this variation can work at an expansive wave period interval with a maximum CWR efficiency achievement of up to 52.14%.
The Effect of Hydrostatic Pressure on the Performance of Oscillating Wave Surge Converter Anton Dwi Prabowo; James Julian; Fitri Wahyuni; Riki Hendra Purba; Nely Toding Bunga
Jurnal Asiimetrik: Jurnal Ilmiah Rekayasa Dan Inovasi Volume 7 Number 1 (2025)
Publisher : Fakultas Teknik Universitas Pancasila

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35814/asiimetrik.v7i1.7912

Abstract

The latest energy demand increasingly drives innovation in ocean wave energy technology, including the Oscillating Wave Surge Converter (OWSC). This consider analyzes the impact of water profundity varieties on the execution of OWSCs put on the seabed. The study was conducted numerically using the Boundary Element Method by testing four variations of air depth at wave periods between 1.2 and 2.8 seconds and wave amplitudes of 0.1 meters. The results show that the optimal depth, equivalent to the flap height (D2), produces the highest maximum displacement due to the balance between hydrostatic pressure and wave energy the flap receives. Conversely, depths that are too shallow (D1) or too deep (D4) result in smaller displacements due to the instability of the movement in shallow air and the attenuation of wave energy in deep air. In addition, more extended wave periods tend to decrease the changing cycle frequency but increase the symmetry of the flap movement at a certain depth.
Utilization of Single and Double Orifice Plates in Pipe Inner Flow Structure by Computational Method Ridwan Daris Naufal; James Julian; Fitri Wahyuni; Riki Hendra Purba; Nely Toding Bunga
Jurnal Asiimetrik: Jurnal Ilmiah Rekayasa Dan Inovasi Volume 7 Number 1 (2025)
Publisher : Fakultas Teknik Universitas Pancasila

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35814/asiimetrik.v7i1.7913

Abstract

The orifice plate is a device that disrupts the flow in the pipe. The disturbed flow results in the formation of flow structures. The flow structure formed can be utilized for several applications such as multi-fluid mixing and microbubble generator. Using orifice plates to utilize the flow structure results in more significant pressure loss. This study aims to identify the characteristics of the flow structure generated by single and double orifice plates with 1D and 2D spacing at various Reynolds numbers, namely Re = 1×104, 5×104, 1×105, and 5×105, as a basis for application in these various applications. The results show that single and double orifice plates can produce flow structure phenomena such as recirculation and vortex regions. The recirculation area is formed smaller in the double orifice plate due to the flow that is separated faster to converge back to the pipe wall but broader so that the flow of the orifice plate is narrower. Increasing the applied Reynold's number causes the separated flow to reconnect to the pipe wall faster, resulting in a smaller recirculation area. Double orifice plates are more suitable for applications that require a certain degree of mixing or pressure distribution, but with a consequent more significant pressure loss. Meanwhile, single plates can be used for simple needs with little pressure loss.
The Analysis of Banana Slices Machine Frame Using Computational Method Reza Najmi Akmal; James Julian; Fitri Wahyuni; Riki Hendra Purba; Nely Toding Bunga
Jurnal Asiimetrik: Jurnal Ilmiah Rekayasa Dan Inovasi Volume 7 Number 1 (2025)
Publisher : Fakultas Teknik Universitas Pancasila

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35814/asiimetrik.v7i1.7914

Abstract

The culinary industry, especially banana chip processing, dramatically supports the economy of micro and small enterprises (MSMEs) in Indonesia. However, the traditional process is time-consuming, especially at the cutting stage. The banana-slicing machine is designed to speed up this process with consistent and efficient cuts. This study analyzes the performance of the banana-slicing machine frame by testing variations in loading (20 N to 200 N) and frame materials, namely Low Alloy Steel, Structural Steel, Stainless Steel, Aluminum Alloy, and Cast Iron, to determine the optimal material. The results showed that Low Alloy Steel is the best material because it has the lowest total deformation, equivalent stress, and strain energy, reflecting high stiffness and load efficiency. With an elastic modulus of 212.5 GPa and an economical price ($1.3–1.5/kg), this material offers the best balance in terms of technical and economics. Structural steel also performed well but was slightly lower than low alloy steel. In contrast, Aluminum Alloy has the highest deformation and strain energy, making it less suitable for this application. Overall, Low Alloy Steel is an ideal choice to improve the efficiency and reliability of the banana-slicing machine.
Numerical Investigation on Aerodynamic Characteristics of Bio-Inspired Nose Airfoil NACA 4415 Fitri Wahyuni; James Julian; Saphira Anggraita Siswanto; Riki Hendra Purba; Fathin Muhammad Mahdhudhu; Elvi Armadani; Nely Toding Bunga
Jurnal Asiimetrik: Jurnal Ilmiah Rekayasa Dan Inovasi Volume 8 Number 1 (2026)
Publisher : Fakultas Teknik Universitas Pancasila

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35814/asiimetrik.v8i1.9428

Abstract

It is widely believed that bionic airfoils can influence aerodynamic performance. Therefore, this study focuses on analyzing the effect of a bio-inspired nose on the NACA 4415 airfoil. This study uses roughtoothed dolphins and spinner dolphins as modifications of the airfoil, which are then tested at Re = 1.6×105 using Computational Fluid Dynamics (CFD). From the simulation results, it was shown that the baseline NACA 4415 has the best aerodynamic performance across all Angles of Attack (AoA). The average percentage increase in Cd for the spinner dolphin is lower, at 40.399% compared to the baseline. On the other hand, the roughtoothed dolphin shows a higher percentage increase in Cd with an average of 51.479% compared to the baseline. While in the Cl data, the rough-toothed dolphin has a larger average percentage decrease, at -10.472%, whereas the spinner dolphin achieves an average decrease of only -5.194% compared to the baseline. Therefore, it can be concluded that the rough-toothed and spinner dolphin modifications do not enhance the aerodynamic performance of the NACA 4415 airfoil at AoA. However, at low AoA, the roughtoothed dolphin modification performs comparably to the baseline NACA 4415 airfoil.
The Influence of Bluff Body Shape Variations on Aerodynamic Characteristics in Flow Around a Cylinder Christian Jovie Yudhananta; Fitri Wahyuni; James Julian; Riki Hendra Purba; Fathin Muhammad Mahdhudhu; Elvi Armadani; Nely Toding Bunga
Jurnal Asiimetrik: Jurnal Ilmiah Rekayasa Dan Inovasi Volume 8 Number 1 (2026)
Publisher : Fakultas Teknik Universitas Pancasila

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35814/asiimetrik.v8i1.9429.2

Abstract

Fluid flow around an object plays an important role in various fields, including aerodynamics, building design, and transportation. This study examines the effect of three two-dimensional bluff body shapes, including Circular, Square, and Diamond, on the flow pattern, drag and lift coefficients, and vortex shedding characteristics. The methodology used is Computational Fluid Dynamics (CFD) simulation for incompressible flow with a Reynolds number of 100. The results show that variations in geometric shapes significantly affect the shape formation, flow stability, and aerodynamic force response. The three bluff body variations were found to produce fluctuating aerodynamic characteristics due to the influence of the von Kármán vortex phenomenon. In the diamond cylinder variation, it was found to be the configuration with the widest shape, having the highest average drag coefficient value of 1.84, and exhibiting the most significant force amplification, with an average lift coefficient value of 0.36 and a Strouhal number (St) of 0.18. Overall, variations in bluff body shapes significantly affect the flow pattern, Vortex Shedding frequency, and the total aerodynamic force acting on the object
Thermal Performance of Analysis of Serpentine Channel Cold Plate for 18650 Cylindrical Lithium-Ion Battery Fitri Wahyuni; James Julian; Rainer Samuel Fourlando; Riki Hendra Purba; Fathin Muhammad Mahdhudhu; Elvi Armadani; Nely Toding Bunga
Jurnal Asiimetrik: Jurnal Ilmiah Rekayasa Dan Inovasi Volume 8 Number 1 (2026)
Publisher : Fakultas Teknik Universitas Pancasila

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35814/asiimetrik.v8i1.9430

Abstract

This research evaluates the thermal performance of a liquid cooling system with serpentine channel inlets for an 18650 cylindrical lithium-ion battery module. The study analyzed an eight-cell module with a baseline configuration and variations featuring two, three, and four serpentine curves using computational fluid dynamics simulations validated against previous experiments. A fixed mass flow rate of 0.0001 kg/s was applied. Results showed all configurations-maintained battery temperatures below 37.5°C, preventing thermal runaway. The Baseline configuration achieved the lowest maximum temperature of 37.447°C and the highest performance factor (J/F factor) of 0.053. The two serpentine curves offered the best temperature uniformity (1.114°C) and highest heat transfer coefficient. Although more serpentine curves reduced maximum temperature, they increased pressure drop, decreasing the J/F factor. The study concludes that the serpentine cold plate design effectively manages thermal containment, with the two-curve configuration providing the best balance of heat transfer and temperature stability.
RANCANG BANGUN MESIN GERINDA COPY CAMSHAFT Nely Toding Bunga; Hendri Sukma; Hasan Hariri; Richard; Y. A. Sihombing
Jurnal Asiimetrik: Jurnal Ilmiah Rekayasa Dan Inovasi Volume 1 Nomor 1 Tahun 2019
Publisher : Fakultas Teknik Universitas Pancasila

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35814/asiimetrik.v1i1.214

Abstract

Mesin gerinda copy camshaft adalah mesin untuk menduplikat atau memperbanyak camshaft. Tujuan dari rancang bangun ini adalah agar pengerjaan pembuatan camshaft menjadi lebih mudah karena mesin melakukan copy master secara otomatis sesuai dengan master tersebut. Metode perancangan yang digunakan adalah metode Ulrich & Eppinger serta metode DFMA sebagai metode manufakturnya. Proses racang bangun mesin gerinda copy camshaft ini meliputi:pembuatan konsep desain, identifikasi bahan, identifikasi mesin dan peralatan yang digunakan, serta identifikasi gambar kerja. Hal yang perlu di perhatikan dalam pembuatan mesin gerinda copy camshaft ini adalah kerapatan sambungan pada rangka atas dan kaki rangka sehingga tidak terjadi getaran pada saat mesin beroperasi. Mesin ini memiliki dimensi panjang 1000 mm, lebar 600 mm, tinggi 500 mm. Pengujian kinerja mesin yang dilakukan dengan cara pengujian secaralangsung membuat camshaft. Hasil pengujian waktu yang dibutukan untuk membuat satu buah camshaft adalah 10 menit, dengan kecepatan putaran 2800 RPM.
Co-Authors A.A. Ketut Agung Cahyawan W Anton Dwi Prabowo Armansyah Christian Jovie Yudhananta Elvi Armadani Fathin Muhammad Mahdhudhu Ferdyanto Fitri Wahyuni Fitri Wahyuni Hasan Hariri Hendri Sukma James Julian James Julian Juri Saedon Lomo Mula Tua Mirza Fauzan Lukiano Rainer Samuel Fourlando Rayhan Fariansyah Billad Reza Najmi Akmal Richard Ridwan Daris Naufal Riki Hendra Purba Rizki Aldi Anggara Ruslan, Wegie Saphira Anggraita Siswanto Waridho Iskandar Waridho Iskandar Wegie Ruslan Y. A. Sihombing Yusuf Wibisono Zaky Assiddiqie