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Penurunan Kerugian Head pada Belokan Pipa dengan Peletakan Tube Bundle , Pratikto; Wahyudi, Slamet
Jurnal Teknik Mesin Vol 12, No 1 (2010): APRIL 2010
Publisher : Institute of Research and Community Outreach - Petra Christian University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9744/jtm.12.1.51-57

Abstract

Fluid flow flowing through an elbow causes separation. Separation leads to vortex, shake and cavity. As a result, the head loss will increase and the pipe installation is potentially damaged. Thus, separation must be eliminated. The separation is identified by the presence of high pressure decreasing in the downstream of elbow. To minimize the pressure decreasing in elbow, we need flow conditioner like a tube bundle. The aim of this research is to identify the influence of tube bundle placement toward the head loss such as pressure drop. The elbow being tested is placed on a pipe installation already equipped by testing aids such as computers and its software, pressure transmitter, and rotameter. The free variable in this study is the distance of the tube bundle from the outlet edge of the pipe turn 2D, 3D, 4D and 5D and fluid flow volume which flows through the installation that are 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900 and 2000 litres/hour. Whereas, the dependent variable is the pressure drop (p) measured by pressure transmitter and the head loss of which the value is obtained from the measurement of pressure drop. The test was conducted on 1.25 inch in diameter elbow with 22 holes of tube bundle and 27 mm in length. To know the head loss, so the pressure drop (p) of fluid at upstream and downstream of the pipe turn are measured using 2 pressure transmitters connected to the computer through ADC (Analog Digital Converter). The data had already recorded in computer was processed using the LabView software to get the averaged value of the pressure drop. Abstract in Bahasa Indonesia: Aliran Fluida yang mengalir melalui belokan pipa menyebabkan terjadinya separasi. Separasi mengakibatkan terjadinya vortex, getaran, dan kavitasi, dimana kerugian tersebut mengakibatkan kerugian head meningkat dan berpotensi merusak instalasi pipa sehingga separasi perlu dihilangkan. Separasi ini ditandai dengan penurunan tekanan yang besar pada bagian hilir belokan pipa. Untuk memperkecil penurunan tekanan pada belokan pipa diperlukan suatu alat pengkondisi aliran (flow conditioner) berupa tube bundle (gabungan pipa). Tujuan dari penelitian ini adalah untuk mengetahui pengaruh peletakan tube bundle tersebut terhadap kerugian head yang berupa penurunan tekanan. Belokan pipa yang diuji dipasang pada instalasi pipa yang telah dilengkapi alat bantu pengujian seperti komputer dengan software-nya, pressure transmitter, dan rotameter. Variabel bebas pada penelitian ini adalah jarak peletakan tube bundle dari sisi keluaran belokan pipa 2D, 3D, 4D dan 5D serta debit aliran fluida yang melewati instalasi yaitu 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900 dan 2000 liter/jam. Sedangkan variabel terikatnya adalah beda tekanan (p) diukur dengan pressure transmitter dan kerugian head yang nilainya diperoleh dari perhitungan beda tekanan tersebut. Pengujian dilakukan pada belokan pipa berdiameter 1,25 inci dengan jumlah lubang tube bundle 22 dan panjang 27 mm. Untuk mengetahui kerugian head yang terjadi, maka beda tekanan (p) fluida antara bagian hulu dan hilir belokan pipa diukur dengan menggunakan 2 buah pressure transmitter yang dihubungkan dengan komputer melalui ADC (Analog Digital Converter). Data yang telah terekam pada komputer diolah dengan bantuan LabView software sehingga diperoleh nilai rata-rata dari beda tekanan yang terjadi. Kata kunci: Kerugian head, tube bundle, belokan pipa.
Premixed Combustion of Coconut Oil on Perforated Burner Wirawan, I.K.G.; Wardana, I.N.G.; Soenoko, Rudy; Wahyudi, Slamet
International Journal of Renewable Energy Development Vol 2, No 3 (2013): October 2013
Publisher : Center of Biomass & Renewable Energy, Dept. of Chemical Engineering, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2.3.133-139

Abstract

Coconut oil premixed combustion behavior has been studied experimentally on perforated burner with equivalence ratio (φ) varied from very lean until very rich. The results showed that burning of glycerol needs large number of air so that the laminar burning velocity (SL) is the highest at very lean mixture and the flame is in the form of individual Bunsen flame on each of the perforated plate hole. As φ is increased the  SL decreases and the secondary Bunsen flame with open tip occurs from φ =0.54 at the downstream of perforated flame. The perforated flame disappears at φ = 0.66 while the secondary Bunsen flame still exist with SL increases following that of hexadecane flame trend and then extinct when the equivalence ratio reaches one or more. Surrounding ambient air intervention makes SL decreases, shifts lower flammability limit into richer mixture, and performs triple and cellular flames. The glycerol diffusion flame radiation burned fatty acids that perform cellular islands on perforated hole.  Without glycerol, laminar flame velocity becomes higher and more stable as perforated flame at higher φ. At rich mixture the Bunsen flame becomes unstable and performs petal cellular around the cone flame front. Keywords: cellular flame; glycerol; perforated flame;secondary Bunsen flame with open tip; triple flame
Premixed Combustion of Kapok (ceiba pentandra) seed oil on Perforated Burner Wirawan, I.K.G.; Wardana, I.N.G.; Soenoko, Rudy; Wahyudi, Slamet
International Journal of Renewable Energy Development Vol 3, No 2 (2014): July 2014
Publisher : Center of Biomass & Renewable Energy, Dept. of Chemical Engineering, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.3.2.91-97

Abstract

Availability of fossil fuels in the world decrease gradually due to excessive fuel exploitation. This situations push researcher to look for alternative fuels as a source of renewable energy, one of them is kapok (ceiba pentandra) seed oil. The aim this study was to know the behavior of laminar burning velocity, secondary Bunsen flame with open tip, cellular and triple flame. Premixed combustion of kapok seed oil was studied experimentally on perforated burner with equivalence ratio (φ) varied from 0.30 until 1.07. The results showed that combustion of glycerol requires a large amount of air so that laminar burning velocity (SL) is the highest at very lean mixture (φ =0.36) in the form of individual Bunsen flame on each of the perforated plate hole.  Perforated and secondary Bunsen flame both reached maximum SL similar with that of ethanol and higher than that of hexadecane. Slight increase of φ decreases drastically SL of perforated and secondary Bunsen flame. When the mixture was enriched, secondary Bunsen and perforated flame disappears, and then the flame becomes Bunsen flame with open tip and triple flame (φ = 0.62 to 1.07). Flame was getting stable until the mixture above the stoichiometry. Being isolated from ambient air, the SL of perforated flame, as well as secondary Bunsen flame, becomes equal with non-isolated flame. This shows the decreasing trend of laminar burning velocity while φ is increasing. When the mixture was enriched island (φ = 0.44 to 0.48) and petal (φ = 0.53 to 0.62) cellular flame take place. Flame becomes more unstable when the mixture was changed toward stoichiometry.
Analisis Perpindahan Panas pada Saluran Berliku Berpenampang Segi Empat dengan Variasi Clearance Belokan Wahyudi, Slamet; Kurniawan, Aris; Hamidi, Nurkholis
Rekayasa Mesin Vol 1, No 1 (2010)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

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Abstract

Heat transfer characteristics in rectangular with a sharp 180o turn have been examined experimentally using the naphthalene sublimation method. The sharp 180° turn was obtained by dividing a rectangular passage into two channels using a divider wall with a rounded tip at the location where the flow negotiates the turn. The channel cross-section (WxH) is 50×25 m, and three turn clearances of 30, 50, and 70 mm have been tested in this study. Local mass transferrates on all walls of the channel have been measured to clarify the heat transfer characteristics in the channel. The result indicated that the highest coefficient of heat transfer was achieved in the channel with turn clearances of 30 mm.Keywords: Heat Transfer Characteristics in Rectangular,Turn Clearances, Mass Transfers
Pengaruh Diameter Inner-Helical Fin Terhadap Characteristic of Performance Counter Flow Heat Exchanger Bula, Muhamad; Wahyudi, Slamet; Hamidi, Nurkholis
Rekayasa Mesin Vol 1, No 3 (2010)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

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Abstract

The study of energy conservation using the head exchanger with different fin shapes havebeen carried out, including research on the counter flow heat exchanger using a helical spiral shaped fin is placed on the inner pipe. The problem lies in the acquisition of the influence of the diameter of the helical fin to the characteristic of performance counter flow heat exchanger. The diameter of the helical fin which the test is 8 mm, 12 mm and 16 mm. The objective is achieved, the effect of the diameter of the helical fin characteristic of performance counter flow heat exchanger in the increase of hot water discharge 400 liters / hour, 500 liters / hour, 600 liters /hour, 700 liters / hour, 800 liters / hr and 900 liters / hour. Method of design of experiments with laboratory-scale experiments using a set-up equipment double tube heat exchanger is the method used. The results obtained, the highest effectiveness for all types of helical fins foundon discharge 400 liters / h with the order from highest to lower the effectiveness of internal diameter of 12 mm reached 17.66%, diameter of 8 mm effectiveness reaches 15:56% and the internal diameter of 16 mm effectiveness of achieving 14.29%. For the plain tube efektiftasobtained 11:48%.Keywords : heat exchanger, the diameter of the helical fin, hot water discharge, effectiveness
Pra Studi Kelayakan Potensi PLTM/PLTA Di Area PT. PJB Unit Pembangkit Brantas Budiono, Budiono; Wahyudi, Slamet; Sutikno, Djoko
Rekayasa Mesin Vol 2, No 1 (2011)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

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Abstract

In accordance with government policy to further optimize the utilization of renewable energy sources, and the policy of PT. PLN (Persero) to reduce the consumption of primary energy derived from fuel, then the PT Pembangkit Jawa-Bali (PT. PJB) plans to optimize the utilization of water resources in the Area PT. PJB Unit Pembangkitan Brantas that have the potential to be developed into minihyro power plants / hydro power plant with a capacity of under 10.0 MW. One purpose of this study is to anticipate the demand for electricity is increasing every year as well as to reduce dependence on primary energy derived from fossil tend thinning, as well as the concern of PT. PJB to environmental sustainability and clean development.Keywords : Pre-Feasibility Study, Potential of Minihydro Power Plants / Hydro Power Pant.
Optimasi Parameter Pemotongan Mesin Bubut CNC Terhadap Kekasaran Permukaan dengan Geometri Pahat yang Dilengkapi Chip Breaker Wibolo, Achmad; Wahyudi, Slamet; Sugiarto, Sugiarto
Rekayasa Mesin Vol 2, No 1 (2011)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

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Abstract

In machining operation, the quality of surface finish is an important requirement for many turned workpieces. Thus, the choice of optimized cutting parameters is very important for controlling the requied surface quality The focus of present experimental study is to optimize for cutting speed, feed rate, and radius chip breaker using two performance measures, metal removal rate and surface roughness. Response Surface Methodology (RSM). has been applied for developing models in the form of multiple regression equations correlating dependent parameters with cutting parameters and radius chip breaker, in a turning process. The central composite rotatable design was used to plan the experiment, and analysis of variance were employed to study the performance characteristics for three variable independent in turning operation. A second-order model which can describe the relation then to find combination between cutting parameters and radius chip breaker which resulting the maximum metal removal rate and minimum surface roughness. The experimental results reveal that the most significant cutting parameters for surface roughness is cutting speed, followed by feed rate and radius chip breaker. Based on the optimization results, recommended cutting speed, feed rate, and radius chip breaker is 35 m/mt, 0,2819 mm/rev, and 0,85 mm. By implementing this parameters, the surface roughness and metal removal rate is 2,18 μm and 6230,80 mm3/mt.Keywords : Surface Roughness, Metal removal rate, response surface methodology, turning
Pengaruh Ketebalan Inner-Helical Fin Terhadap Charcteristic of Performance pada Head Exchanger Usman, Ishak; Wahyudi, Slamet; Argo, Bambang Dwi
Rekayasa Mesin Vol 1, No 3 (2010)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

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Abstract

Effect of inner-helical fin on the rate of heat transfer and flow friction factor in a double pipe heat exchanger (double tube heat exchanger) to make a split and disrupt the flow pattern of a streamlined flow of the fluid flowing in the pipe section in the (inner tube) that cause turbulence (molecule-molecule level of randomness good fluid) that can increase the heat transfer rate in the the pipe . Inner-helical fin has a varied thickness of 1 mm, 22 mm and 3 mm are mounted on the pipe where the inside diameter of the inner-helical fin attached to the wall in the inner pipe. Hot water discharge on the inner pipe ditelitil ranging from 400 to 900 liters / h with interval increase in 100 liter / hour and the volumetric flow rate of cold water on the outer tube (outertube) is kept constant 900 liters / hour. The test results of each inner-helical fin thickness compared with the test results without the inner-helical fin (plain tube) and obtained the overall heat transfer rate has increased 60 to 65% of the plain tube, heat exchanger effectiveness of58.56 to 63, 64% and friction factor of 63.13 to 63.51 of the plain tube.Keywords : Inner-helical fin, Heat exchanger, rate of heat transfer, friction factor
Pengaruh Alkalisasi Komposit Serat Kelapa-Poliester Terhadap Kekuatan Tarik Maryanti, Budha; Wahyudi, Slamet
Rekayasa Mesin Vol 2, No 2 (2011)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

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Abstract

The purpose of this research is to analyze the effect of alkalization on the tensile strength and strain of coconut fiber composites with polyester matrix by varying the concentration of NaOH as follow 0%, 2%, 5% and 8%. Alkalization is one of modifications natural fibers to improve fiber-matrix compatibility.The method of this research used a hands lay-up method. As follow the 1st coconut fiber treated without alkalization or 0% alkalization and the 2nd coconut fiber immersed in alkaline solution (2%, 5% and 8% NaOH) for 1 hour. Then, each treatment specimen molded to composite according to standard tensile test ASTM D638 –I. Coconut fiber volume fraction 30% and 70% polyester, and arranged coconut fiber straightly. And used the matrix polyester resin type 157 BTQN with hardener MEKPO 1%.The results of this research showed that coconut fiber reinforced composites with NaOH concentrations of 0%, 2%, 5% and 8% respectively has a tensile strength that is 90,144 MPa, 93.75 MPa, 97,356 MPa and 94,151 MPa. The optimum concentration limit of 5% NaOH produced the highest tensile strength 97,356 MPa, while the composite of coconut fiber without alkalization has the lowest tensile strength 90,144 MPa. Keywords: coconut fiber-polyester composites, alkalization, tensile strength
Komposit Hibrid Polyester Berpenguat Serbuk Batang dan Serat Sabut Kelapa Lumintang, Romels C. A.; Soenoko, Rudy; Wahyudi, Slamet
Rekayasa Mesin Vol 2, No 2 (2011)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

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Abstract

Sawdust coconut trunks of palm trees and fiber coconut coir are two waste materials from the processing of coconuts and coconut tree trunks sawmill waste are plentiful materials can be utilized for producing composites using polyester resins. Both each properties materials as follow polyester resin: liquid in the open air conditions, sawdust coconut and coconut coir fiber properties is lightweight and fragile nature of the polyester adhesive used as a binder (binder) between fiber coconut coir and sawdust coconut palm tree trunks as a filler. The variation volume fraction between the sawdust and coconut trunks of fiber coconut coir in polyester resin influence mechanical properties for each composition of this composite. By comparizing the volume fraction of either polyester, sawdust coconut palm tree trunks and fiber coconut coir (Coir coconut) using tensile test standard ASTM D638-I, and the ASTM D6110 for impact testing. The result of tensile and impact test, obtained that the optimum percentage 30:10 per cent, mean tensile strength on 95.953 N/mm2 , mean elasticity 0,125 % , mean elasticity modulus 768.702 N/mm2, mean absorbed energy 2,679 J and mean impact value 0,068 J/mm2. Keywords: Polyester, Sawdust coconut, coconut coir fiber, mechanical properties