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Journal : Rotasi

Studi Eksperimental pada Emulator Surya Berdasarkan Intensitas Matahari Terhadap Unjuk Kerja Sel Surya 10 Wp Tipe Polycristalline Tira, Hendry Sakke; Natsir, Abdul; Anwar, Muhamad Saiful
ROTASI Vol 19, No 4 (2017): VOLUME 19, NOMOR 4, OKTOBER 2017
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (428.849 KB) | DOI: 10.14710/rotasi.19.4.237-242

Abstract

Energi merupakan salah satu kebutuhan utama dalam kehidupan manusia. Peningkatan kebutuhan energi dapat merupakan indikator peningkatan kemakmuran, namun bersamaan dengan itu juga menimbulkan masalah dalam usaha penyediaannya, karena manusia hanya mengandalkan energi fosil yang tentunya persediaannya masih sangat terbatas dan semakin menipis. Indonesia terletak di daerah khatulistiwa sehingga memiliki intensitas penyinaran matahari yang baik sepanjang tahun. Kondisi penyinaran ini potensial untuk digunakan dalam pembangkitan listrik tenaga surya (PLTS). PLTS merupakan teknologi ramah lingkungan yang memanfaatkan energi sel surya fotovoltaik dengan cara mengkonversi energi cahaya yang dipancarkan oleh matahari menjadi energi listrik. Tujuan dari penelitian ini adalah mengetahui pengaruh intensitas cahaya lampu terhadap arus titik daya maksimum (Impp), tegangan titik daya maksimum (Vmpp), daya maksimum power point (Pmpp), dan efisiensi dari panel surya 10 WP tipe polycristalline pada alat solar emulator. Penelitian ini dilakukan dengan merubah intensitas cahaya lampu pada alat solar emulator berdasarkan intensitas cahaya matahari tanggal 17-25 Maret 2016. Berdasarkan penelitian yang telah dilakukan, menunjukkan bahwa intensitas cahaya lampu mempunyai pengaruh terhadap Impp, Vmpp, Pmpp, dan Efisiensi dari panel surya 10 WP tipe polycristalline. Semakin tinggi intensitas cahaya lampu maka semakin tinggi pula nilai Impp, Vmpp, Pmpp, dan efisiensi yang diperoleh. Efisiensi panel surya tertinggi diperoleh pukul 12:00-12:40 WITA pada tanggal 22 Maret 2016 sebesar 4,14 %.
Numerical Study of Flat-top Piston Head Structure Under Different Materials Hendry Sakke Tira; Muhammad Ponco Zulfikar; I Made Adi Sayoga
ROTASI Vol 25, No 1 (2023): VOLUME 25, NOMOR 1, JANUARI 2023
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/rotasi.25.1.1-6

Abstract

Piston is an important component of two-wheeler since it is able to generate high pressure and convey combustion energy into crank rotation. Piston is typically made of aluminium alloy and other materials that can endure extremely high pressure and heat on the surface during combustion. Aluminium alloy and magnesium alloy are two distinctive materials that are frequently used in piston head. The objective of this study is to use numerical analysis to investigate and analyse a flat-top piston head made of two different materials. The design process allows usage Solidworks software, and the analysis process makes use of Ansys software. The Ansys simulation is intended for evaluating the maximum stress, total deformation variability, and safety factor for each material analysed. The findings from the analysis indicate that the deformation of the piston head made of aluminium alloy is smaller than that of magnesium. Whereas the aluminium alloy has a lower safety factor than magnesium. The von Mises stresses for the two materials, however, are essentially equal.
Numerical Analysis of the Drag Coefficient on Energy-Efficient Vehicle Prototypes Hendry Sakke Tira; Muhammad Agus Muliawan; Syahrul Syahrul
ROTASI Vol 25, No 3 (2023): VOLUME 25, NOMOR 3, JULI 2023
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/rotasi.25.3.46-51

Abstract

The focus of this investigation is to determine the drag coefficient on the prototype vehicle and also the pressure profile on the entire body of the prototype. The study was carried out on a prototype vehicle that would compete at Shell Eco-Marathon Asia-Pacific and Middle East 2023. The test was performed on an energy-efficient vehicle prototype built by the Mandalika Desantara Team, a team of mechanical engineering students at Mataram University. To accomplish this, a CFD approach simulation was performed using the Ansys 2023 R2 simulation software - fluent flow with a comparison of the drag coefficient and average pressure and wind speed of 30 km/h. According to the simulation results, the average drag coefficient value on the prototype design is 0.194. The highest average pressure can be detected on the front of the vehicle, where that part has a maximum pressure of 101374 Pa. While the airflow over the prototype body has the highest average speed of around 10 m/s. Based on these results, the prototype vehicle design still needs to be improved in order to compete in similar competitions.
The Effect of Various Two-wheeler Camshaft Materials on Dynamic Response Using Finite Element Analysis Tira, Hendry Sakke; Dwilingga, Ikhsan
ROTASI Vol 25, No 4 (2023): VOLUME 25, NOMOR 4, OKTOBER 2023
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/rotasi.25.4.68-74

Abstract

A camshaft from a 4-stroke engine operating at idle with an average speed of 650 rpm was studied. The study was carried out using the finite element method and the Ansys software. The study was carried out to determine the dynamic response (reaction force, stress distribution, and deformation) of a camshaft circuit operating under torsional pressure at 650 rpm for 1 s. Analysis studies were carried out by varying the camshaft materials such as structural steel, aluminum alloy, and stainless steel. The results of this numeric study show that the structural steel camshaft has the greatest total deformation when compared to the other two materials. Stainless steel has the highest equivalent stress value, followed by structural steel, and aluminum alloy has the lowest. These findings also suggest that aluminum alloy has a better structural response than other materials. This is due to the aluminum alloy having the lowest stress of 239.87 MPa. This is supported by the relatively high safety factor value of 2.165, which is higher than the other two materials.
Designing an Energy-efficient Prototype Vehicle by the Mandalika Desantara Racing Team Tira, Hendry Sakke; Nuarsa, I Made; Renaldy, Renaldy
ROTASI Vol 26, No 3 (2024): VOLUME 26, NOMOR 3, JULI 2024
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/rotasi.26.3.44-49

Abstract

In order to participate in the international fuel-efficient vehicle competition, a team from the Mechanical Engineering department of Mataram University has prepared a prototype vehicle. The competition is The Shell Eco-Marathon, held at the International Pertamina Mandalika Circuit in Lombok in July 2023 and attended by several teams from abroad. For this purpose, the team has developed an energy-efficient prototype vehicle using a two-wheeler engine. The team has modified the two-wheeler engine to achieve more fuel-efficient consumption compared to conventional vehicles. The study involves checking the two-wheeler engine's condition, conducting engine startup experiments, and analyzing engine performance. The Mandalika Desantara racing team reduced the piston diameter to minimize the combustion chamber volume. The results of the engine modification on the prototype vehicle show a fuel consumption rate of 71.66 km/l when driving on the Mandalika circuit. However, this figure has not yet reached the desired level of efficiency, considering that the estimated fuel consumption of vehicles with conventional motor engines is around 40-50 km/l.