cover
Article Per Year (5 Year)
All
Home Page
OAI Link
Editorial Team
Contact
Reviewer
Google Scholar
Contact Name
-
Contact Email
-
Phone
-
Journal Mail Official
-
Editorial Address
-
Location
Kota semarang,
Jawa tengah
INDONESIA
Rotasi
Published by Universitas Diponegoro
ISSN : 1411027x     EISSN : 24069620     DOI : -
Core Subject : Engineering,
Mechanical Engineering
Arjuna Subject : -
Articles 676 Documents
 54   55   56   57   58 
Simulasi Karakteristik Co-Firing Batubara - Sekam Padi pada PLTU Batubara Pulverized Coal Kapasitas 400 MWe Nur Cahyo; Ruly Bayu Sitanggang; Meiri Triani; Rasgianti Rasgianti; Eko Supriyanto; Paryanto Paryanto
ROTASI Vol 24, No 2 (2022): VOLUME 24, NOMOR 2, APRIL 2022
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/rotasi.24.2.43-53

Abstract

A study on co-firing using coal and rice husk biomass has been carried out on a pulverized coal power plant with a capacity of 400 MWe by varying the co-firing biomass ratio from 0 to 50%. The mixing of coal fuel and rice husk biomass in the model is carried out before entering the pulverizer/mill. After the model iteration shows convergence, the output simulation is validated by comparing the simulation output value with the design and actual parameter values. The evaluation is carried out by comparing the simulation results of baseline conditions with co-firing conditions on the parameters of performance, power output, equipment condition, energy consumption itself, and the impact on emission products. The addition of 1% of the co-firing ratio using rice husks showed a decrease in the boiler efficiency (HHV) by 3.19%. Net plant heat rate and SFC increased by 5.22% and 2.53%. Gross output power decreased by 2.53%. ESP power consumption and total auxiliary power increased by 220% and 17.25%. Furthermore, co-firing using risk husk also reduces SO2 emission and increases the particulate rate.
Effect of Extruder Temperature on Dimensional Accuracy and Surface Roughness of Fused Deposition Modeled (FDMed) PLA and PLA/Wood Composite Juan Pratama; Noverdo Mayanda; Didik Sugiyanto
ROTASI Vol 24, No 2 (2022): VOLUME 24, NOMOR 2, APRIL 2022
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/rotasi.24.2.1-9

Abstract

The ability of Fused Deposition Modeling (FDM) 3D printing to create complex products makes this technology increasingly popular and widely used by both hobbyists and even industrial scale. Despite the advantages of FDM technology, the poor dimensional accuracy and surface finish of the FDM-printed product is one of the major drawbacks of this process. Several studies have shown that printing parameters can affect the quality and surface finish of the printed polymers products. In this paper, the effect of extruder temperature on dimensional accuracy and surface roughness of FDM-printed PLA and PLA/Wood composite were investigated through an experimental approach. The results showed that the extruder temperature was proven to affect the roughness and dimensional accuracy of FDM-printed PLA and PLA/Wood composite. The different behavior of polymers and polymer matrix composites concerning temperature variations is evident and briefly discussed.
Back Matter Rotasi Vol. 24 No. 2 April 2022
ROTASI Vol 24, No 2 (2022): VOLUME 24, NOMOR 2, APRIL 2022
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/rotasi.24.2.App. 1-4

Abstract

Pembuatan Sisipan Sol Sepatu Dari Material Komposit Silicone Rubber Menggunakan Cetakan Berbahan Dasar Kayu Kevin Dwi Ananta Tarigan
ROTASI Vol 24, No 2 (2022): VOLUME 24, NOMOR 2, APRIL 2022
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/rotasi.24.2.54-60

Abstract

Sepatu merupakan salah satu kebutuhan manusia yang berguna untuk melindungi kaki. Selain itu, kegunaan sepatu saat ini disesuaikan dengan aktifitas yang dilakukan seperti acara formal, olahraga hingga peningkat gaya hidup. Sepatu memiliki variasi dari bahan yang baik sampai bahan yang jelek. Saat kita memilih sepatu, kebanyakan dari kita memilih model dan kenyamanannya. Oleh karena itu bahan pembuatan sepatu dititik beratkan pada sifat-sifat untuk bagian atas, sol dalam dan sol luar yang berhubungan dengan kenyaman dalam pemakaian. Saat manusia berdiri tegak, ke dua telapak kaki bagian belakang  menanggung beban 60% dari berat tubuh. Saat berjalan dan tumit menghentak di landasan beban satu kaki di area tumit bisa mencapai 70% dari berat tubuh. Sehingga dibutuhkan suatu insole sepatu untuk mengatasi permasalahan tersebut. Penelitian ini bertujuan untuk membuat cetakan insole sepatu berbahan dasar kayu, serta mencetak insole sepatu dan meneliti hasil cetakan insole sepatu. Proses perancangan cetakan menggunakan software Solidwork, dilanjutkan dengan proses CAM / pembuatan G code menggunakan software Rhinoceros 6. Proses permesinan yang digunakan dalam pembuatan cetakan insole sepatu adalah Non-konvensional permesinan yaitu dengan mesin CNC (Computerized Numerical Control). Proses permesinan yang dilakukan adalah proses milling untuk pembuatan contour dari insole sepatu pada cetakan kayu. Variasi komposisi talc yaitu 10% dan 25%. Hasil cetakan insole sepatu menggunakan cetakan berbahan dasar kayu secara akurasi dimensi , pada cetakan kaki kiri memiliki akurasi dimensi terbesar 0,19% dan yang terkecil yaitu 2,23%. Sedangkan pada cetakan kaki kanan memiliki akurasi dimensi terbesar yaitu 0,557% dan yang terkecil yaitu 2,08%. Kemudian secara organoleptis menurut SNI 12-0172-200 tentang Sepatu Kanvas Untuk Umum, sudah memenuhi persyaratan, yakni bagian atas atau permukaan sol tidak boleh cacat berupa lepuh, sobek, dan warna tidak merata.Kata kunci:  cetakan kayu, silicone rubber, shoe insole
Perancangan Mesin Balancing Dinamis pada Putaran Maksimal 1485 RPM dengan Metode 4 Massa Coba Imron Fahreza Yudha; Murni Murni
ROTASI Vol 24, No 4 (2022): VOLUME 24, NOMOR 4, OKTOBER 2022
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/rotasi.24.4.%p

Abstract

Unbalance is defined as the condition that exists in the rotor when a vibratory force or motion is exerted on its bearings as a result of centrifugal force. Balancing is the treatment of unbalanced components by providing another centrifugal force that will oppose the original centrifugal force or by eliminating the force. Balancing process aims to reduce vibrations that occur in the rotor system by adding or reducing mass in the rotor. To determine the state of unbalance, a vibration meter is used to measure the value of vibrations that occur in unbalanced test objects.The dynamic balancing machine is designed on a laboratory scale as a support for the lecture process related to testing the balance of objects that work in rotation on the Mechanical Design Engineering S.Tr campus. In the design and construction of this dynamic balancing test tool, the design was carried out using SolidWorks software with a motor power of 1 hp with a maximum rotational speed of 1485 RPM and using a fixed shaft mounted on a test object with 2 hole disks for placement of the test mass.In the test, the 4 dynamic trial mass method was used, with the condition of the disk object being an unbalance mass of 10 grams with a different position in the two planes. This increase in mass causes the object to experience dynamic imbalance, and the vibration value becomes higher than the initial state of the machine. Then a balancing calculation was carried out, the balancing mass value for the left rotor was 5.278 g at position 00 and 13.17 g at position 2700 , while on the right rotor a counterweight mass was 0.17 g at position 00 and 2.44 g at position position 2700. After the balancing mass is installed, the results of the decrease in vibration value due to the addition of mass are 74% on the left bearing and 88% on the right bearing. In this test, the rotor was tested at several rotational speeds and all of them showed a decrease in the vibration value.
Analisa Kerusakan pada Secondary Superheater Tube di Sistem Boiler pada Power Plant Akibat Proses Soot Blowing R Rusnaldy
ROTASI Vol 24, No 4 (2022): VOLUME 24, NOMOR 4, OKTOBER 2022
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/rotasi.24.4.48-56

Abstract

Makalah ini berisi analisa penyebab kerusakan pada permukaan pipa secondary superheater di suatu Power Plant berupa terjadinya penipisan pada dinding pipa. Pipa sudah beroperasi sekitar 10 tahun. Pipa belum mengalami pergantian karena memang didesain untuk beroperasi selama kurang lebih 30 tahun. Material pipa  adalah baja ASTM SA-213-T12. Ada bagian dari pipa yang ditemukan telah mengalami penipisan ketebalan pada bagian permukaan luar. Analisa kegagalan dilakukan terhadap pipa superheater yang meliputi inspeksi visual, analisa metalurgi, analisa mekanik dan termal serta melakukan simulasi untuk mendukung proses terjadinya kegagalan pada pipa superheater. Hasil analisis menunjukkan bahwa tidak ditemukan indikasi kerusakan pipa akibat deformasi plastis dan termal. Kerusakan berupa penipisan dinding permukaan pipa bagian luar disebabkan oleh peristiwa erosi akibat proses soot blowing yang digunakan untuk menghilangkann deposit fly ash yang menempel pada permukaan luar pipa.
Analisis Fisika dan Kimia Material Polimer Ramah Lingkungan Edible film Berbahan Rumput Laut E-Cottonii Sebagai Pengganti Kemasan Plastik Agus Dwi Putra; Yayi Febdia Pradani; Bella Cornellia Tjiptady
ROTASI Vol 24, No 4 (2022): VOLUME 24, NOMOR 4, OKTOBER 2022
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/rotasi.24.4.8-15

Abstract

Penelitian ini bertujuan untuk mmenanggulangi masalah sampah plastik terutama di indonesia. Adapun target dalam penelitian ini yaitu untuk menguji material polimer ramah lingkungan pengganti kemasan plastik yakni edible film. Pengujian pada penelitian ini dibagi menjadi dua jenis yaitu pengujian secara fisika dan secara kimia. Pengujian fisika dimaksudkan untuk menguji tingkat ketebalan edible film, kuat Tarik, elongasi, dan titik leleh. Kemudian pengujian kimia ditujukan untuk menguji kadar air dan kadar karbohidrat edible film. Edible film yang diujikan meliputi tiga jenis variasi dengan masing-masing variasi memiliki campuran tepung jagung dan gliserol dengann konsentrasi takaran yang berbeda. Hasil menunjukkan bahwa ketebalan maksimum edible film mencapai 0,17 mm sedangkan ketebalan minimum sebesar 0,062 mm. Berikutnya hasil pengujian kuat Tarik didapatkan bahwa kuat Tarik maksimum mencapai 82 N/cm2 sedangkan kuat Tarik minimum sebasar 18 N/cm2. Pada pengujian tingkat elongasi didapatkan hasil bahwa elongasi maksimum sebesar 33% dan elongasi minimum sebesar 20,5%. Selanjutnya pada pengajuan titik leleh edible film didapatkan hasil titik leleh maksimum sebesar 75,8oC sedangkan titik leleh minimum sebesar 65,9oC. Pada pengujian kadar air dan kadar karbohidrat didapatkan kadar air dan karbohidrat maksimum adalah 13,67% dan 71,68%. Sedangkan kadar ari dan kadar karbihidrat minimum sebesar 12,9% dan 60,8%.
Studi Eksperimen Tungku Biomassa pada Proses Pengeringan Chip Umbi Porang melalui Rumah Plastik Ultra-Violet (Solar Dryer) Sistem Hibrid Verdy A. Koehuan; Eflinda Milo; Defmit B. N. Riwu
ROTASI Vol 24, No 4 (2022): VOLUME 24, NOMOR 4, OKTOBER 2022
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/rotasi.24.4.57-64

Abstract

This study aims to determine the performance of a biomass stove with coconut shell biomass as fuel for the drying process in a hybrid system dryer house. The method used is an experimental method by testing and analyzing the efficiency of the biomass furnace and the efficiency of the drying house on the variation of the initial mass of coconut shells in the gasification chamber. The test results show that the furnace efficiency or the highest gasification efficiency occurs in combustion with an initial mass of 15 kg of coconut shell, which is 6.18%. Meanwhile, the initial mass of 12 kg and 18 kg showed furnace efficiency of 4.07% and 4.66%, respectively. The efficiency of this biomass furnace is still low, because of the pyrolysis process, which takes place at a relatively low temperature with relatively slow combustion. In the process of drying porang tuber chips through an ultra-violet plastic housing (solar dryer) this hybrid system showed a drying efficiency of 9.58% and a drying house efficiency of 30.02%. The use of biomass heat energy is 9.96%, while the largest heat energy comes from solar radiation into the drying house of 89.11%.
Analisa Cacat yang Terjadi pada Proses Pembuatan Roda Gigi Lurus Melalui Proses Pengecoran Besi Cor Nodular yang Menggunakan Chill Natalino Fonseca D.S. Guterres
ROTASI Vol 24, No 4 (2022): VOLUME 24, NOMOR 4, OKTOBER 2022
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/rotasi.24.4.16-25

Abstract

Gear surface hardening by using chill in the casting method is very unique in the gear manufacturing process because it shortens the stages of gear manufacturing. The problem that needs attention is the occurrence of defects in the tooth profile after the gears are cast. Porosity defects and shrinkage or expansion defects often occur in the final solidification step in nodular cast iron materials. The use of chill is a fast cooling rate on the surface between the cast and molded material. However, it is easy for air bubbles to occur in the process of forming spheroidal graphite at the end of the solidification step. The purpose of this study was to analyze shrinkage or expansion defects and porosity defects that occur on the tooth profile surface. Casting uses an electric furnace at a temperature of 1400oC and an open mold using silica sand. Before the pouring step, the chill will be heated at a temperature of 700oC. Dimensional change defects are detected by measuring the dimensions of the tooth profile. While the porosity defects were tested by radiography to determine the cavities in the chilled area, then the percentage value of porosity used the pycnometric method and the Archimedes principle. Shrinkage defects in the tooth thickness area are on average 0.2mm (0.04%), while porosity defects in chilled areas are cavities in the surface area of the tooth profile having the highest porosity value reaching 0.108wt.% because it is influenced by Cooling speed too high.
Heat Transfer Characteristics of Hybrid Nanofluids Al2O3/ZnO as Working Fluid in Electronic Cooling Systems Devia Gahana Cindi Alfian
ROTASI Vol 24, No 4 (2022): VOLUME 24, NOMOR 4, OKTOBER 2022
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/rotasi.24.4.65-71

Abstract

The use of nanofluid as a working fluid to improve equipment performance has been growing recently. Utilization of nanofluid hybrids is the development of mono nanofluid to improve heat transfer performance which is still not maximized when using mono nanofluid. This research was conducted to determine the performance of hybrid nanofluids with composition of Al2O3/ZnO-Distilled Water as working fluids in electronic devices. The process of making hybrid nanofluids was carried out using a two-step method using an ultrasonic cleaner for 3 hours. Furthermore, the test was carried out by varying the ratio of Al2O3 and ZnO nanoparticles at 25%:75%, 50%:50%, 75%:25% at exactly 0.5% volume fraction. Based on the test results, adding nanoparticles can increase the heat transfer in the working fluid. The use of nanofluid hybrids at varying ratios of Al2O3:ZnO (50%:50%) with a flow rate of 0.7 L/min has the highest heat transfer coefficient value of 220.14 W/m2.oC at Reynolds Number 178.4 and requires pumping power of 0.649 W. Moreover, distilled water with a flow rate of 0.7 L/min has the heat transfer coefficient of 77.48 W/m2.oC at Reynolds Number 130.1 and requires a pump power of 0.425 W.

Page 56 of 68 | Total Record : 676

 54   55   56   57   58 

Filter by Year

2000 2025


Reset
Filter By Issues
All Issue Vol 27, No 3 (2025): VOLUME 27, NOMOR 3, OKTOBER 2025 Vol 27, No 2 (2025): VOLUME 27, NOMOR 2, JULI 2025 Vol 27, No 1 (2025): VOLUME 27, NOMOR 1, JANUARI 2025 Vol 26, No 4 (2024): VOLUME 26, NOMOR 4, OKTOBER 2024 Vol 26, No 3 (2024): VOLUME 26, NOMOR 3, JULI 2024 Vol 26, No 2 (2024): VOLUME 26, NOMOR 2, APRIL 2024 Vol 26, No 1 (2024): VOLUME 26, NOMOR 1, JANUARI 2024 Vol 25, No 4 (2023): VOLUME 25, NOMOR 4, OKTOBER 2023 Vol 25, No 3 (2023): VOLUME 25, NOMOR 3, JULI 2023 Vol 25, No 2 (2023): VOLUME 25, NOMOR 2, APRIL 2023 Vol 25, No 1 (2023): VOLUME 25, NOMOR 1, JANUARI 2023 Vol 24, No 4 (2022): VOLUME 24, NOMOR 4, OKTOBER 2022 Vol 24, No 3 (2022): VOLUME 24, NOMOR 3, JULI 2022 Vol 24, No 2 (2022): VOLUME 24, NOMOR 2, APRIL 2022 Vol 24, No 1 (2022): VOLUME 24, NOMOR 1, JANUARI 2022 Vol 23, No 4 (2021): VOLUME 23, NOMOR 4, OKTOBER 2021 Vol 23, No 3 (2021): VOLUME 23, NOMOR 3, JULI 2021 Vol 23, No 2 (2021): VOLUME 23, NOMOR 2, APRIL 2021 Vol 23, No 1 (2021): VOLUME 23, NOMOR 1, JANUARI 2021 Vol 22, No 4 (2020): VOLUME 22, NOMOR 4, OKTOBER 2020 Vol 22, No 3 (2020): VOLUME 22, NOMOR 3, JULI 2020 Vol 22, No 2 (2020): VOLUME 22, NOMOR 2, APRIL 2020 Vol 22, No 1 (2020): VOLUME 22, NOMOR 1, JANUARI 2020 Vol 21, No 4 (2019): VOLUME 21, NOMOR 4, OKTOBER 2019 Vol 21, No 3 (2019): VOLUME 21, NOMOR 3, JULI 2019 Vol 21, No 2 (2019): VOLUME 21, NOMOR 2, APRIL 2019 Vol 21, No 1 (2019): VOLUME 21, NOMOR 1, JANUARI 2019 Vol 20, No 4 (2018): VOLUME 20, NOMOR 4, OKTOBER 2018 Vol 20, No 3 (2018): VOLUME 20, NOMOR 3, JULI 2018 Vol 20, No 2 (2018): VOLUME 20, NOMOR 2, APRIL 2018 Vol 20, No 1 (2018): VOLUME 20, NOMOR 1, JANUARI 2018 Vol 19, No 4 (2017): VOLUME 19, NOMOR 4, OKTOBER 2017 Vol 19, No 3 (2017): VOLUME 19, NOMOR 3, JULI 2017 Vol 19, No 2 (2017): VOLUME 19, NOMOR 2, APRIL 2017 Vol 19, No 1 (2017): VOLUME 19, NOMOR 1, JANUARI 2017 Vol 18, No 4 (2016): VOLUME 18, NOMOR 4, OKTOBER 2016 Vol 18, No 3 (2016): VOLUME 18, NOMOR 3, JULI 2016 Vol 18, No 2 (2016): VOLUME 18, NOMOR 2, APRIL 2016 Vol 18, No 1 (2016): VOLUME 18, NOMOR 1, JANUARI 2016 Vol 17, No 4 (2015): VOLUME 17, NOMOR 4, OKTOBER 2015 Vol 17, No 3 (2015): VOLUME 17, NOMOR 3, JULI 2015 Vol 17, No 2 (2015): VOLUME 17, NOMOR 2, APRIL 2015 Vol 17, No 1 (2015): VOLUME 17, NOMOR 1, JANUARI 2015 Vol 16, No 4 (2014): VOLUME 16, NOMOR 4, OKTOBER 2014 Vol 16, No 3 (2014): VOLUME 16, NOMOR 3, JULI 2014 Vol 16, No 2 (2014): VOLUME 16, NOMOR 2, APRIL 2014 Vol 16, No 1 (2014): VOLUME 16, NOMOR 1, JANUARI 2014 Vol 15, No 4 (2013): VOLUME 15, NOMOR 4, OKTOBER 2013 Vol 15, No 3 (2013): VOLUME 15, NOMOR 3, JULI 2013 Vol 15, No 2 (2013): VOLUME 15, NOMOR 2, APRIL 2013 Vol 15, No 1 (2013): VOLUME 15, NOMOR 1, JANUARI 2013 VOLUME 14, NOMOR 4, OKTOBER 2012 VOLUME 14, NOMOR 3, JULI 2012 VOLUME 14, NOMOR 2, APRIL 2012 VOLUME 14, NOMOR 1, JANUARI 2012 VOLUME 13, NOMOR 4, OKTOBER 2011 VOLUME 13, NOMOR 3, JULI 2011 VOLUME 13, NOMOR 2, APRIL 2011 VOLUME 13, NOMOR 1, JANUARI 2011 Volume 12, Nomor 4, Oktober 2010 Volume 12, Nomor 3, Juli 2010 Volume 12, Nomor 2, April 2010 Volume 12, Nomor 1, Januari 2010 Volume 11, Nomor 4, Oktober 2009 Volume 11, Nomor 3, Juli 2009 Volume 11, Nomor 2, April 2009 Volume 11, Nomor 1, Januari 2009 Volume 10, Nomor 4, Oktober 2008 Volume 10, Nomor 3, Juli 2008 Volume 10, Nomor 2, April 2008 Volume 10, Nomor 1, Januari 2008 Volume 9, Nomor 4, Oktober 2007 Volume 9, Nomor 3, Juli 2007 Volume 9, Nomor 2, April 2007 Volume 9, Nomor 1, Januari 2007 Volume 8, Nomor 4, Oktober 2006 Volume 8, Nomor 3, Juli 2006 Volume 8, Nomor 2, April 2006 Volume 8, Nomor 1, Januari 2006 Volume 3, Nomor 2, April 2001 Volume 3, Nomor 1, Januari 2001 Volume 2, Nomor 4, September 2000 More Issue