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Redaksi Jurnal Rekayasa Mesin Jurusan Teknik Mesin Fakultas Teknik, Universitas Brawijaya Jl. MT. Haryono 167 Malang, Jawa Timur Indonesia 65145
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Kota malang,
Jawa timur
INDONESIA
Rekayasa Mesin
Published by Universitas Brawijaya
ISSN : 23381663     EISSN : 24776041     DOI : 10.21776/ub.jrm
Core Subject : Engineering,
Rekayasa Mesin is published by Mechanical Engineering Department, Faculty of Engineering, Brawijaya, Malang-East Java-Indonesia. Rekayasa Mesin is an open-access peer reviewed journal that mediates the dissemination of academicians, researchers, and practitioners in mechanical engineering. Rekayasa Mesin accepts submission from all over the world, especially from Indonesia. Rekayasa Mesin aims to provide a forum for national and international academicians, researchers and practitioners on mechanical engineering to publish the original articles. All accepted articles will be published and will be freely available to all readers with worldwide visibility and coverage. The scope of Rekayasa Mesin are the specific topics issues in mechanical engineering such as design, energy conversion, manufacture, and metallurgy. All articles submitted to this journal can be written in Bahasa and English Language.
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Articles 965 Documents
Simulation of Fluid Flow Through Sedan Car YRS 4 Doors with Speed Variation using CFD Ilmi, Syamsuri; Lillahulhaq, Zain; Yusron, M
Jurnal Rekayasa Mesin Vol 11, No 3 (2020)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.jrm.2020.011.03.11

Abstract

Aerodynamic forces that occur around the vehicle must be considered since it involves safety, ergonomic, and fuel consumption. To reduce fuel consumption, the vehicle should be built as aerodynamic as possible to minimize drag forces. The vehicle becomes unstable at high speed due to increasing lift force. To balance the vehicle at high speed, a downforce should be generated to keep the tires attached to the road surface. Each type of car has a various value of aerodynamic force due to its design, dimension, and cross-section area. The characteristics of streamflow around the car are discussed in this paper. This research simulated 2D sedan car YRS 4 Doors in the steady condition in various velocities, i.e. 23 m/s, 26 m/s, and 40 m/s. This simulation used the Quad Pave mesh model and run in k-ε implicit turbulence model. The characteristics could be observed from the qualitative and quantitative data. The quantitative data used as measurable data were Coefficient of Pressure (CP) and Drag Coefficient (CD).  Quantitative data was shown to outline a better visual explanation of the streaming characteristic. The qualitative data used in this paper are path lines, velocity vectors, and contours. The high-velocity stream results in a low value of CP. When the fluid flowed at high speed through a surface, it had low pressure. The coefficient of drag in the high-speed car decreased as the free stream increased. The value of the coefficient of drag (Cd) from this research was app. 0.567.
Characterization of Aluminum Matrix Metal Composite Hybrid Reinforced With SiCw/(Al2O3-Mg) on Thermal Conductivity and Hardness Suarsana, Ketut; Soenoko, Rudy; Negara, DNK Putra; Sunu, P.W.
Jurnal Rekayasa Mesin Vol 12, No 1 (2021)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.jrm.2021.012.01.18

Abstract

Characteristics of composite materials that are light, strong, heat resistant, and high hardness are needed in their application. This study aims to obtain a hard material and good heat conductivity, with the innovation of making aluminum matrix composites (AMC) from aluminum powder as a matrix, combined with silicon-carbon whisker (SiCw) and alumina particles (Al2O3p), and adding Magnesium through the powder process metallurgy. The method of making composites was carried out by means of powder metallurgy. The research variables composition I, II, and II with Al/(SiCw+Al2O3/Mg), were given temperature treatment: 500, 550, and 600oC. The test results show that there is an increase in the mechanical properties of the composites both from variations in composition and also from variations in treatment temperature because the bond resulting from the addition of Al2O3 reinforcement has hard and fine grain properties. The physical and mechanical properties of the test results are in the form of the highest density at composition I, 600oC (2,699 gr/cm3) while the hardness at composition III is 600oC (42,438 HV) and heat conductivity at composition III, 600oC (185,183 Watt/m.oC). Scanning with SEM showed that the pore size decreased from the treatment temperature of 500oC to 600oC due to phase changes and a stronger bond between the matrix and the reinforcement. So that the influence of composition and temperature will affect the thermal conductivity, hardness, and density of the composites.
Experimental Study on The Effect of Cross Feed of Surface Grinding on the Vibration and the Surface Roughness of Hardened Tool Steel OCR12VM Anam, Chairul; Muzaka, Khairul; Pamuji, Dian Ridlo
Jurnal Rekayasa Mesin Vol 11, No 3 (2020)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.jrm.2020.011.03.2

Abstract

The grinding process is a machining process to obtain qualified surface roughness levels and high dimensional accuracy. There are two types of processes in the grinding process, namely the roughening and finishing processes. The vibration effect of the roughing process can damage and shorten the life of the tool/machine, while in the finishing process, the effect of vibration will reduce the dimensional accuracy, shape, and surface smoothness of the workpiece. This study aims to determine the effect of crossfeed on the amplitude of vibration and surface roughness of the workpiece on the surface grinding process. The materials used are hardened tool steel OCR12VM with a variety of grinding stone types A46QV and A80LV made of aluminum oxide. The Variables of process parameters are crossfeed (mm / step) and depth of cut (mm). The measurement of vibrations uses an accelerometer, which is processed by the math CAD program in the form of amplitude and frequency. For surface roughness measurements, it is used the MT-301 surface test with 5 sample points and a sample length of 0.8 mm. The results show that the greater the cross-feed value, the bigger the amplitude of the vibration level and the surface roughness of the workpiece. The magnitude of the amplitude of the vibration on the acceleration that occurs in the grinding stone type A46QV starts from 6,7369 -18.7525 g.rms, while the grinding stone type A80LV starts from 5.0904 g.rms to 18.2821 g.rms. The surface roughness achieved in both grit 46 and grit 80 is from N3 to N5.
Perbandingan Interaksi Karbon Aktif dengan Polaritas Minyak Nabati terhadap Karakteristik Pembakaran Premixed Purnami, Purnami; Wardana, I Nyoman Gede
Jurnal Rekayasa Mesin Vol 12, No 1 (2021)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.jrm.2021.012.01.9

Abstract

Crude oil consumption has increased since the discovery of crude oil-fueled engine technology. However, the increase in crude oil consumption is not offset by the productivity of the product. This results in a reduced availability of crude oil. One solution found was to use alternative fuels from vegetable oils. Several researches have proven that vegetable oils can be used as fuel. The results of the research found potential in jatropha oil and palm oil. However, jatropha oil and palm oil contain glycerol compounds which can affect the results of its combustion, because glycerol can absorb heat and result in firing more difficult. Based on that, modification and development are needed to support the use of jatropha oil and palm oil as alternative fuels by studying oil polarity and adding catalysts for coconut shell-activated carbon. Jatropha oil has low polarity (C18) which is more volatile than palm oil which has high polarity (C13). The variation used in this research is the addition of activated carbon with a concentration of 0 ppm, 200 ppm, and 400 ppm in each oil. The addition of activated carbon will facilitate evaporation because oil molecules become more reactive more freely.
Chatter Vibration Comparison Between Normal Helix Angle and Variable Helix Angle in End Milling Process Based on Spectrum Analysis Sonief, Achmad As'ad; Fauzan, Arda Nur; Azlan, Fachry; Bashori, Muhammad Aziz
Jurnal Rekayasa Mesin Vol 11, No 3 (2020)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.jrm.2020.011.03.25

Abstract

Chatter vibration in machining processes is often found in cutting processes which will decrease the machining efficiency and the surface quality of the products. Chatter is a relative vibration of the cutting tool and workpiece caused by the fluctuation of cutting force that is concerned to be a self-excited vibration. The variable Helix Angle Cutting tool which has pitch angle variation will also inflict different tooth passing frequencies on the flute that stand contiguous and trim the resonance frequency. This research aims to compare chatter vibrations that occurred between Normal Helix Angle and Variable Helix Angle cutting tool based on spectrum analysis on cutting parameter variety (depth of cut; rotation speed; feed rate milling). The outcome is spectrum analysis can detect the chatter phenomenon, measure the natural frequency (38-42 Hz), and also compare chatter vibrations between two tools appropriately.
Development of Accuracy Evaluation Method for Open Loop Educational CNC Milling Machine Winarno, Agustinus; Lasiyah, Sus; Tulung Prayoga, Benidiktus; Aris Hendaryanto, Ignatius; Sukidjo, Fransiskus Xaverius
Jurnal Rekayasa Mesin Vol 12, No 1 (2021)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.jrm.2021.012.01.23

Abstract

The open-loop educational computer numerical control (CNC) milling machine requires accuracy verification in order to ensure its accuracy and functionality. In this paper, the new verification method is proposed based on the length measurement using the fringe counting of He-Ne laser interferometry. The ideal translation length is defined by the number of electric pulses generated by the micro-stepping driver, while the actual length is measured using He-Ne laser interferometry. In the experimental process, the data of the fringe pattern of the He-Ne laser and the number of electric pulses which drive the stepper motors were simultaneously acquired using an oscilloscope. Hence, the data has been analyzed to obtain the ideal and actual lengths by using an in-house program developed in Python. By comparing the actual translation and ideal length, the accuracy of the educational CNC milling machine has been evaluated to be 50 µm for the length up to 200 mm.
Pengaruh Doping Cu terhadap Karakteristik Material dan Ketahanan Karbon pada Anoda Ni1-X-CuX-BCZY untuk PSOFC Setiawan, Nanang; Tseng, Chung-Jen; Shen, Chin Tien; Wardana, ING
Jurnal Rekayasa Mesin Vol 11, No 3 (2020)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.jrm.2020.011.03.16

Abstract

The purpose of this study is to investigate the microstructure characteristics of the Ni1-xCux-BCZY anode and to analyze the carbon resistance by doping Cu into the Ni-BCZY anode. Ni1-xCux and BaCe0.7Zr0.1Y0.2O3-𝛿 (BCZY) powder were prepared by solid-state reaction with Ni1-xCux /BCZY = 60:40 wt%. The powder is calcined at a temperature of 700 °C, sintered at 1450 °C, and reduced by pure H2. The results of the Ni1-xCux-BCZY microstructure show an increase in the average particle size from 2.71 to 2.88 µm with increasing calcination time from 0.5 to 1.5 hours. Furthermore, the conductivity of Ni1-xCux-BCZY (x = 0.1) is lower than Ni1-xCux-BCZY (x = 0), this is associated with enhancement electron scattering, which correlatives with large metal particle obtained. The optimum conductivity of Ni1-xCux-BCZY(x=0.1) is obtained at a calcination time of 0.5 hours. Furthermore, NiCu anode can effectively increase the carbon resistance while using methane as a fuel.
Pressure Drop dan Pola Aliran Dua Fase (Air-Udara) Melewati Pipa Groove Vertikal Aji, Supa Kusuma; Widhiyanuriyawan, Denny; Yuliati, Lilis
Jurnal Rekayasa Mesin Vol 11, No 3 (2020)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.jrm.2020.011.03.7

Abstract

This research was conducted to observe the effect of adding grooves in the two-phase flow of water-air in the same direction through a vertical pipe to changes in pressure and fluid flow patterns. Test section in the form of pipes with grooves made of acrylic material with a length of 100 cm and an internal diameter of 2.54 cm. The geometric shape of the acrylic pipe is modified by giving a groove in the direction of the pipe along the test section. Grooves used amounted to 4 and 16 and pipes without grooves used as a comparison. Tests are carried out by flowing water and air that has been mixed through the inlet side upward. The ratio of air velocity to water velocity (VG / VL ) is 0.24-1.13. The method used in this study is experimental. Retrieval of pressure drops data is done by using a differential pressure transmitter. Visual observations are also made using a DSLR camera equipped with a flash and video observations using a smartphone with slow-motion mode. The results showed changes in flow patterns and pressure drop values. Slugs in pipes with grooves disappear faster and pressure drops are lower than pipes without grooves.
Estimasi Jumlah Penghuni Ruangan Berdasarkan Konsentrasi CO2 Dengan Metode Bayesian MCMC Rahman, Haolia; Handaya, Devi; Budianto, Teguh
Jurnal Rekayasa Mesin Vol 12, No 1 (2021)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.jrm.2021.012.01.14

Abstract

The number of occupants in the building is important information for building management because it is related to security issues, evacuation, and energy saving. This article focuses on estimating the number of occupants using the Bayesian Monte Carlo Markov chain (MCMC) method based on indoor CO2 levels. Probability theory underlies the Bayesian MCMC principle, where the mass balance equation of indoor CO2 is used as a physical model of estimation calculations. Determination of the variables in the mass balance equation is investigated to obtain the effect on the accuracy of the estimated number of occupants. It found that the higher the standard deviation of the input variable on the physical model, the higher the error estimation produced. In addition, the Bayesian MCMC algorithm is tested in a real-time scheme of test-chamber. The result shows an estimated error of 39%. Rapid changes influence estimation errors in actual occupants relative to the sample interval and the time delay of the estimation.
Pengaruh Kecepatan Pengadukan pada Proses Stircasting terhadap Sifat Mekanik pada Paduan Aluminium Jauhari, Mochamad Helmi; Darmadi, Djarot B; Widodo, Teguh Dwi
Jurnal Rekayasa Mesin Vol 12, No 1 (2021)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.jrm.2021.012.01.5

Abstract

The composite material is a material composed of a mixture or combination of two or more of the major elements that macro differ in shape and material composition that basically can not be separated. In this research, the aluminum used was the outcome of production cesspool with the addition of volcanic dust from Mount Kelud by 2% as reinforcement. The stir casting process is the casting process by adding a material (powder form) in pure metal (aluminum), which has been melted and then stirring constantly. After that, the composite materials (the volcanic dust from Mount Kelud) were mixed slowly into the stirred liquid material. In this research, the variations of stirring speed were 0,200,300,400,500  and 600 rpm. The stirring each time for 4 minutes. In this study, the stirring speed in the casting process was 0, 200, 300, 400, 500, and 600 rpm. Tensile test, Impact test, and microstructure observations were carried out on the casting results. From these tests, the highest modulus of elasticity and impact value was obtained at the 600rpm stirring process. It may due to globular grains are more evenly distributed. And the result of metallographic testing was stirring speed could affect the amount and density of composite grain structure. The faster the stirring, the grain structure was getting smaller and close.