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All Journal Jurnal Dedikasi SINTEK JURNAL: Jurnal Ilmiah Teknik Mesin Rekayasa Mesin R.E.M (Rekyasa Energi Manufaktur) Jurnal Turbo : Jurnal Program Studi Teknik Mesin Jurnal Mesin Nusantara Seminar Nasional Hasil Riset dan Pengabdian (SNHRP) Indonesian Journal of Innovation Studies PELS (Procedia of Engineering and Life Science) Procedia of Social Sciences and Humanities eProceedings of Management Prosiding SEMNAS INOTEK (Seminar Nasional Inovasi Teknologi) Journal of Aerospace Systems and Engineering Innovations Academia Open
Rachmat Firdaus
Universitas Muhammadiyah Sidoarjo
Aerospace Engineering Agriculture, Biological Sciences & Forestry Humanities Automotive Engineering Chemical Engineering, Chemistry & Bioengineering Civil Engineering, Building, Construction & Architecture Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Economics, Econometrics & Finance Education Electrical & Electronics Engineering Energy Engineering Environmental Science Industrial & Manufacturing Engineering Languange, Linguistic, Communication & Media Law, Crime, Criminology & Criminal Justice Materials Science & Nanotechnology Mathematics Mechanical Engineering Medicine & Pharmacology Public Health Social Sciences Transportation Other

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Analisis Pengaruh Variasi Bentuk Sudden Enlargement terhadap Head Loss pada Aliran Udara Laminar Wibisono, Satria Agung; Akbar, Ali; Fahruddin, A’rasy; Firdaus, Rachmat; Syahril, Muhammad
Jurnal Mesin Nusantara Vol 8 No 2 (2025): Jurnal Mesin Nusantara
Publisher : Universitas Nusantara PGRI Kediri

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29407/jmn.v8i2.24788

Abstract

Fenomena sudden enlargement pada sistem perpipaan merupakan salah satu penyebab utama terjadinya head loss yang dapat menurunkan efisiensi aliran fluida. Penelitian ini bertujuan untuk menganalisis pengaruh variasi bentuk sudden enlargement terhadap kehilangan energi pada aliran fluida laminar dengan menggunakan tiga variasi geometri, yaitu Square Edge, Rounded Edge, dan Projecting Edge. Pengujian dilakukan pada pipa berbahan akrilik menggunakan manometer U sebagai alat ukur tekanan dengan dua titik pengukuran, masing-masing pada diameter 12,7 mm dan 50 mm. Dua tingkat laju aliran udara diuji, yaitu 6 L/menit dan 4 L/menit. Data tekanan yang diperoleh diolah untuk menghitung kecepatan aliran dan head loss menggunakan persamaan dasar fluida. Hasil penelitian menunjukkan bahwa bentuk geometri memiliki pengaruh signifikan terhadap besarnya head loss. Pada laju aliran tinggi (6 L/menit), geometri Square Edge menghasilkan head loss terendah, sedangkan Rounded Edge memberikan performa optimal pada laju aliran rendah (4 L/menit). Geometri Projecting Edge secara konsisten menghasilkan head loss tertinggi pada kedua kondisi. Temuan ini menunjukkan bahwa pemilihan geometri sudden enlargement harus disesuaikan dengan kondisi operasi sistem. Penelitian ini diharapkan dapat menjadi referensi dalam perancangan instalasi perpipaan yang lebih efisien dan mendukung optimasi energi pada sistem transportasi fluida.
Analisis Distribusi Kecepatan Fluida pada Daerah Boundary Layer di dalam Pipa Lurus Secara Eksperimental Barafi, Keigant Abdullah; Akbar, Ali; Fahruddin, A’rasy; Firdaus, Rachmat
Jurnal Mesin Nusantara Vol 8 No 2 (2025): Jurnal Mesin Nusantara
Publisher : Universitas Nusantara PGRI Kediri

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29407/jmn.v8i2.24789

Abstract

Boundary layer adalah lapisan batas yang terbentuk akibat gesekan antara permukaan penampang dan fluida, sehingga terjadi gradiensi kecepatan. Penelitian ini mengamati gradiensi kecepatan fluida pada boundary layer dalam pipa lurus menggunakan metode eksperimental. Distribusi kecepatan fluida diukur menggunakan pipa akrilik berdiameter 1” dan jarum tumpul berdiameter 1,5 mm yang menyerupai tabung pitot dengan sistem perbedaan tekanan stagnasi dan tekanan statis. Fluida dengan berbagai viskositas dan laju aliran diuji untuk memahami pengaruhnya terhadap karakteristik lapisan batas. Dengan flowrate 10 liter/menit menunjukkan hasil pengukuran kecepatan fluida meningkat seiring bertambahnya jarak radial pada dinding pipa mulai dari =2 mm (0,334 m/s), =5,5 mm (0,341 m/s), =7,5 mm (0,425 m/s), =10,5 mm (0,438 m/s), dan pada =12,7mm (0,443 m/s). Kecepatan tertinggi tercatat di titik tengah pipa yang membuktikkan bahwa hasilnya sesuai dengan karakteristik boundary layer, di mana gaya gesekan dan viskositas berkurang.
ANALISA GAS BUANG PADA MOTOR HONDA REVO FI 2019 110CC DENGAN MENGGUNAKAN CAMPURAN BAHAN BAKAR Aziz, Eriq Helmy; Akbar, Ali; Firdaus, Rachmat
Prosiding SEMNAS INOTEK (Seminar Nasional Inovasi Teknologi) Vol. 6 No. 3 (2022): PROSIDING SEMINAR NASIONAL INOVASI TEKNOLOGI TAHUN 2022
Publisher : Universitas Nusantara PGRI Kediri

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29407/inotek.v6i3.2664

Abstract

Penelitian ini bertujuan untuk mengetahui hasil analisa gas buang pada percampuran bahan bakar shell super , shell v-power, pertamax dan pertamax turbo pada kendaaraan bermotor Pengujian properties dari shell super, shell v-power , pertamax dan pertamax turbo. Properties bahan bakar yang dihitung adalah yang berkaitan dengan karakteristik utama pembakaran yaitu: nilai Emisi gas buang sesuai dengan standar ASTM dengan perbandingan 50 : 50 percampuran bahan.dengan mengetahui berapa hasil nilai HC, CO, CO2 dan CO pada kendaraan bermotor.
Analisis Nilai Elongasi Material Terhadap Cracksheet Pada Proses Deep drawing Nozzle pada Unit Evaporator wira yudha, bhima endra; Akbar, Ali; Firdaus, Rachmat; Mulyadi, Mulyadi
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.v14i2.4401

Abstract

Penelitian ini bertujuan menganalisis nilai elongasi pada material Galvanized (DX51D, DX54D, DX53D) dan Stainless Steel (SUS304, SUS316, SUS441) sebagai parameter utama dalam proses deep drawing nozzle unit evaporator. Uji tarik dilakukan untuk menentukan kemampuan deformasi plastis tanpa menyebabkan keretakan, serta pencarian indikasi cracksheet yang dapat terjadi selama proses pembentukan. Hasil menunjukkan bahwa material stainless steel, khususnya SUS304 dan SUS441, memiliki nilai elongasi tertinggi sebesar 45%, menunjukkan ketahanan unggul terhadap deformasi ekstrem. Sementara itu, DX54D menjadi galvanis dengan elongasi tertinggi (36%) dan tidak mengalami retak saat deep drawing, berbeda dengan DX51D dan DX53D yang menunjukkan gejala cracksheet. Batas elongasi minimum untuk menghindari kegagalan struktural pada deep drawing ditentukan sekitar 30%. Pemilihan material dengan elongasi tinggi serta optimalisasi parameter proses menjadi krusial dalam menjamin kualitas dan efisiensi produksi. Hasil ini memberikan dasar untuk menentukan material optimal berdasarkan kombinasi performa teknis dan efisiensi biaya.
Effect Of Additional Variations Of Etanol Fuel On Exhaust Gas Emissions On Yamaha 125cc Motorcycles: Pengaruh Variasi Penambahan Bahan Bakar Etanol Terhadap Emisi Gas Buang Pada Sepeda Motor Yamaha 125cc Nur Afif Rozikin; Rachmat Firdaus
Academia Open Vol. 4 (2021): June
Publisher : Universitas Muhammadiyah Sidoarjo

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21070/acopen.4.2021.1969

Abstract

The very rapid development of the automotive world nowadays has made it a daily necessity for the community, in everyday human life it cannot be far from the name automotive, both in terms of transportation, and all kinds of supporting household needs. This can be seen from the number of motorbikes operating more when compared to other types of land transportation vehicles such as: cars. As we know, all transportation vehicles today still use non-renewable fuels. In line with the growing demand for fuel in the transportation, industrial and household sectors. Then this will result in unfavorable impacts on the environment, namely the residual exhaust gases from combustion. The remaining exhaust gases cause air pollution which can pollute the environment and can even destroy ozone which is very useful for living things on earth. In this study we use a reference concept which is then used as a concept, how is the effect of variations in the addition of ethanol fuel to exhaust gas emissions of Yamaha 125cc motorcycles by using variations in the percentage of ethanol 10%, 20%, 30% and variations in engine speed during testing, at 4600rpm, 5700rpm, and 6200rpm. It was found that the best torque and power were produced at a percentage of 10% ethanol at 6200 rpm indicating a power of 6.4 Hp and a torque of 10.6 Nm, and the best results on 30% preentae ethanol at 4600rpm showed 0.01% CO gas, 37 ppm HC gas, 1.8% CO2 gas and 18.06% O2 gas.
Optimization of Friction Stir Welding Parameters for AA6061-T651 Aluminum Alloy: Defect Analysis and Process Improvement: Optimalisasi Parameter Pengelasan Gesekan Aduk untuk Paduan Aluminium AA6061-T651: Analisis Cacat dan Peningkatan Proses Mulyadi; Rachmat Firdaus; Rahmania Sri Untari
Academia Open Vol. 8 No. 1 (2023): June
Publisher : Universitas Muhammadiyah Sidoarjo

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21070/acopen.8.2023.6665

Abstract

Friction Stir Welding (FSW) is an eco-friendly process known for high-quality joints without filler metal. This study investigated the physical properties of FSW-welded joints in AA6061-T651 aluminum alloy by varying the concave shoulder angle. Optimal process parameters were determined through Taguchi optimization using an Orthogonal Array design. Macro and micro testing revealed overlap defects, kissing bond defects, and wormholes in some samples. Systematic experimentation identified key parameters to avoid defects, including tool rotation speed, welding speed, tool tilt angle, tool indentation angle, and shoulder depth. Visual inspection and microstructural analysis played a crucial role in assessing weld quality. Optimizing welding parameters, such as rotational speed, welding speed, temperature, and tool geometry, was highlighted as crucial for defect-free joints. The study offers valuable insights for researchers and professionals in the field, promoting the advancement and application of FSW in aluminum alloy welding. Highlight: FSW: An environmentally friendly welding process with good joint quality. Defect Analysis: Identification of overlap defects, kissing bond defects, and wormholes in welded joints. Process Optimization: Determination of optimal parameters to avoid defects, including tool rotation speed, welding speed, tool tilt angle, tool indentation angle, and shoulder depth. Keyword: Friction Stir Welding, AA6061-T651 Aluminum Alloy, Welded Joint Analysis, Process Optimization, Defect Prevention
RCM II Identifies Critical GTG Components and Maintenance Strategy: RCM II Mengidentifikasi Komponen GTG yang Kritis dan Strategi Pemeliharaan Zulfikar, Raihan Maulana; Firdaus, Rachmat
Indonesian Journal of Innovation Studies Vol. 26 No. 4 (2025): October
Publisher : Universitas Muhammadiyah Sidoarjo

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21070/ijins.v26i4.2131

Abstract

General Background: Gas Turbine Generator systems play a critical role in industrial power generation, where failures can cause significant operational and safety risks. Specific Background: Conventional maintenance strategies are often reactive and fail to prioritize component criticality, leading to inefficient resource allocation. Knowledge Gap: There is limited application of structured Reliability Centered Maintenance II integrated with Failure Mode and Effects Analysis to systematically identify failure risks and optimize maintenance strategies in GTG systems. Aims: This study aims to apply RCM II to determine critical components, analyze failure modes using FMEA, and define appropriate maintenance strategies based on risk levels. Results: The analysis identifies key components such as the compressor and combustion system as high-priority failure modes, with RPN values reaching 360 and 336 respectively. Other components fall into medium and low priority categories. Maintenance strategies are classified into proactive tasks using RCM II, simple FMEA-based actions, and run-to-failure approaches. Novelty: The study integrates RCM II decision diagrams with detailed RPN-based prioritization for GTG maintenance planning. Implications: The findings provide practical guidance for improving maintenance efficiency, optimizing labor allocation, and supporting reliable operation in industrial energy systems. Keywords: RCM II, Gas Turbine Generator, FMEA Analysis, Risk Priority Number, Maintenance Strategy Key Findings Highlights Risk evaluation highlighted dominant failure contributors in power generation unit Structured prioritization grouped components into three maintenance categories Decision-based tasks defined preventive and corrective operational actions
Co-Authors Ahmad Ahfas Ajitiyo Dananjoyo Alfiansyah Satrio Wicaksono Ali Akbar Ali Akbar Annisa Nurbaiti Aziz, Eriq Helmy Barafi, Keigant Abdullah Deannes Isynuwardhana Edi Widodo Efendi, Muchammad Fahruddin, A'rasy Fahruddin, A’rasy Ferdiansyah, Faris Fernanda, Ardhi Shefta Hamzah Setiawan Huesein, Wa Ode Asma’ul Husna Iqlima, Anita Rahma Nur iswanto Iswanto Iswanto Mochammad Nur Rizki Mohammad Afif Fajar Mohammad Dani Iswanto Muhammad Syahril MULYADI Mulyadi Mulyadi Mulyadi Mulyadi Nia Nuraeni Suryaman Nur Afif Rozikin Pangestu, Eka Adji Paramitha Amelia Kusumawardani Perbawa, Dafva Ari Prantasi Harmi Tjahjanti Prasetya, Fikri Putra , Ahmad Nurwanda Bawono Rachmadani, Dhaniar Gumelang Rahmania Sri Untari Ribangun Bamban Jakaria Sari, Ghulam Muhammad Abdu Shodiq, Ja’far Siti Cholifah Waluyo, Satrio Wibisono, Satria Agung wira yudha, bhima endra Yulianto, Achmad Irfan Zulfikar, Raihan Maulana