ROTOR
Not a member yet
257 research outputs found
Sort by
ANALISIS SIFAT MEKANIK HASIL PENGELASAN ALUMINIUM AA 1100 DENGAN METODE FRICTION STIR WELDING (FSW)
Get PDFAluminum and aluminum alloys have properties that are less well when coMPared to steel, such as specific heat and has a high conductivity. They are also easily oxidized and form an aluminum oxide Al2O3 which have a high melting point. Consequently, when they are welded the fusion between base and weld metal will be blocked. Moreover, if the cooling process is too fast it will form a smooth cavity ex-pouch of hydrogen. Friction stir welding (FSW) is a challenging alternative for joining aluminum alloy. In FSW, process occur in the solid state (solid state joining). In this research, some attempts were carried out to find the best quality of welding, in term of mechanical properties and microstructure. Tool rotation speed was varied at 780, 980, 1120 rpm. Whereas, feed rate used was keep constantly at 15 mm/min. The material to be welded is a- 4.0 mm thick aluminum AA 1100 strips. Result showed that the highest strength obtained is 56.528 MPa at 1120 rpm and the lowest strength obtained is 38.472 MPa at 980 rpm. Wormholes and the lack of penetration defects are the main things that reduce the tensile strength. From micro observations known on the grains shape of the stir zone, FeAl3 particles is spread more evenly in matrix of Al  due to the stir process during the welding process. Hardness tests showed that the weld metal is softer than the base metal. Keywords: Aluminum, welding, FS
OPTIMALISASI PRESTASI MESIN BENSIN DENGAN VARIASI TEMPERATUR CAMPURAN BAHAN BAKAR PREMIUM DAN ETANOL
Get PDFTo reduce dependence on oil usage that increasing every day, many countries have adopted a substitution of petroleum fuels with renewable fuels such as ethanol is used as a blend in gasoline. Because ethanol can be produced from agricultural products such as corn, sugarcane, rice, etc., then the ethanol is one of the best alternative fuel in motor gasoline. Blending gasoline with ethanol would not fully produce a homogeneous mixture, need for additional treatment to obtain a more homogeneous results, one way is to heat the fuel. If the fuel is heated, there will be expansion or changes in fuel volume, in addition to the viscosity of the fuel will be decreased. It’s can be explained by the theory of thermodynamics, which states that the higher the temperature of a fluid, the fluid molecules will move quickly so at fixed volume will increase the pressure. Fuel with low viscosity will be atomized better, resulting smaller granules. With these conditions the process of mixing fuel with air will be more homogeneous so that the fuel burn more. The results obtained from testing the performance of the engine is the highest maximum torque obtained when using T40˚C fuel, with 6.37 Nm at 3400 rpm, increased 22.5%. The highest maximum power obtained when using T40˚C fuel with 3.450 HP at 5600 rpm, increased 5.11%. lowest Fuel Consumption average obtained at T40˚C fuel with 4.46% more efficient. Keywords: gasoline, ethano
APLIKASI REFRIGERAN CAMPURAN LPG/CO2 PADA SISTEM REFRIGERASI KOMPRESI UAP
Get PDFA new binary mixture of R744 and R290 as an alternative natural refrigerant to halocarbon was presented in this paper. Its environmental performance is friendly. It has an ODP of zero and GWP smaller than 20. This work investigates the result of an experimental study carried out to determine the performance of a refrigeration system. Experimental studies for this mixture were performed on machine installation A.C. Bench, P.A. Hilton. Ltd.. Serial No. A573/41154. LPG-CO2 mixing ratio used was 90:10; 85:15; 80:20% by mass, with the total mass of the mixture of 300 grams. The results showed that the increase of air velocity at the evaporator with CO2 concentrations is constant, which is causing the increase on refrigeration capacity. While the addition of CO2 concentration mixed refrigerant causing decrease on refrigeration capacity. This is due to the increasing CO2 concentration causes a decrease in enthalpy of the mixture, which causes the refrigeration capacity is also decreased. Increased of air flow velocity at the evaporator at a concentration of CO2 remains causing compressor work resulting decrease. This is due to an increase in air velocity causing an increase in temperature of the evaporator so that the required compressor work is decrease. Increase of concentration of CO2 in the mixture causes the compressor work increases because CO2 has a high-pressure work so that the compression load is increasing and the compressor were employment given compressor is also increasing. Increase of air flow rate causes the coefficient of performance of refrigeration systems is getting increased. While the increase in CO2 concentrations has led to the decrease of performance coefficient Keywords: Hydrocarbon refrigerant, LPG, CO2, coeffisient of performance
PENGARUH KECEPATAN POTONG, GERAK MAKAN DAN KETEBALAN PEMOTONGAN TERHADAP GETARAN BENDA KERJA PADA PROSES SEKRAP
Get PDFShaping  machine  is  a  machine  tool  used  to  modify the  surface  of  the workpiece into a flat surface, good story, angled, and the flow corresponding to the shape  and  size  desired. Shaping process  is  a  process  similar  to  the  lathe,  the difference is in motion the process of intersection. In the process shaping machine tools with straight main motion back and forth vertically or horizontally. Chisel cut motion  in  a  straight  motion  of  the  workpiece  is  translational. In  this  case  the workpiece and cutting tool is at rest moving straight translation. At the chisel to move back, move the workpiece also bait (feeding). So your back will chisel stuck in a moving workpiece. Shaping machinery industry in the world used to work on areas of flat, convex, concave, disorderly, in a horizontal position, vertical, or oblique, etc. From the research results can be seen the effect of the parameters used to the chatter values obtained chisel and roundness. Can be seen carving the smallest value of the vibration generated from experimental data 1 is =0.5562 m/s2 at n = 5 m/min, f = 0,2 and a = 1 mm. While the biggest chisel vibration acceleration values obtained from experimental data collection to 27 for = 5,1659 m/s2 at n = 11 m/min, f = 0,6 and a = 2 mm. The results in general that the value of vibration acceleration, after the feeding motion raised the value of vibration acceleration of the workpiece increases, this is because the larger the feed motion is used then the resulting anger is also growing thicker so that the necessary cutting force increases. As a result, the tangential force is also up and cause the radial force and moment coupling. Keywords: cutting speed. feeding, dept of cut,  workpiece and vibration
PENGARUH PUTARAN SPINDEL, GERAK MAKAN DAN KEDALAMAN POTONG TERHADAP GETARAN SPINDLE HEAD HASIL PROSES DRILLING
Get PDFThe process  of  drilling  or  often  referred  to  as  the  drill  is  the  simplest machining  process  among  other  machining  processes.  Usually  in  the  garage  or workshop process is called the drill, although this term is actually less accurate. The process of the drill is intended as a process of making a round hole by using a drill (twist drill). While the process of drilling is the process to expand / enlarge the hole that can be done with a drill rod is not only done on the drill machine, but it could also machine tool, machine freis, or drilling machines. From the research results can be seen the effect of the parameters used to the chatter values obtained chisel. Can be seen carving the smallest value of the vibration generated from experimental data 1 is =0.6361 m/s2 at n = 136 rpm, f = 0,07 and a = 14 mm. While the biggest chisel vibration acceleration values obtained from experimental data collection to 27 for =,4267 m/s2 at n = 681 rpm, f = 0,22 and a = 20 mm. From the regression equation can be known parameters of the most influential pieces of depth of cut. The results in general that the value of vibration acceleration and determination, after  the meal motion raised the value of vibration acceleration chisel and roundness are also growing, this was due to the greater movement of food is used then the resulting anger is also getting thicker  so that the required cutting force increasing large. Consequently tangential force is also rising and  causing the radial force and moment coupling. Moments and radial forces which cause bending and twisting of the chisel, consequently the greater the roundness deviation. Key words: drilling, feeding, dept of cut, spindle head and vibration
STUDI EKSPERIMENTAL PERBANDINGAN ALIRAN MELINTASI DUA SILINDER SIRKULAR DAN SILINDER ELIPS TERSUSUN TANDEM DAN INTERAKSINYA TERHADAP DINDING DATAR
Get PDFThe study was conducted to obtain information about the characteristics of fluid flow that touches the surface of the bluff body. Bluff body in the form of circular and elliptical cylinders and brought near a wall. Phenomenon found is used to predict the aerodynamic loads on the bluff body and leads to a drag reduction efforts.Elliptic cylinder and circular cylinder are arranged in tandem position with longitudinal distance (L/D = 1.5) and gap distance variation (G/D) between cylinders and flat wall are 0.067, 0.133, 0.2, 0.267. Fluid flow characteristics investigated experimentally on open loop wind tunnel. The experimental results are used to explain flow interaction phenomenoum which is resulted coefficient pressure distribution (Cp) on the cylinder, on the flat wall and velocity distribution on the upstream and downstream. The placement of the elliptic cylinder at G/D = 0.267 exhibits the lowest drag. The whole research was done on the Reynolds number 53574 based on circular cylinder diameter. Keywords: circular cylinder, elliptic cylinder, drag force
EVALUASI KOROSI BAJA KARBON RENDAH ASTM A36 PADA LINGKUNGAN ATMOSFERIK DI KABUPATEN JEMBER
Get PDFAtmospheric corrosion is corrosion or degradation of materials in the atmosphere that occurs naturally. The corrosion rate varies for different materials and is influenced by several environmental factors, such as: humidity, temperature, and pollutant (NOx, SOx, Cl-, CO2). This research studies the corrosion rate of low carbon steel ASTM A36 in kabupaten Jember environment with different area. The location of research was done in the side of beach (Watu Ulo), the centre of city (Gajah Mada street) and the mountain range (Rembangan). The dimension of test racks and specimens for atmospheric exposure were prepared in accordance with the ASTM G 50 – 76. The cleaning of all corrosion products were done in accordance with the ASTM G 1- 90. The result shows that the highest corrosion rate is in the Watu Ulo as big as 2,82 mpy, than Gajah Mada street as big as 0,919 mpy. The lowest corrosion rate is in Rembangan as big as 0,844 mpy. From the micro photographs, it is found that low carbon steel ASTM A36 corrode by uniform and pitting formation. Keywords: atmospheric corrosion, uniform, pittin
ANALISA PENGARUH KARAKTERISTIK KEKUATAN PERSAINGAN PORTER TERHADAP KINERJA SEKOLAH DENGAN PENDEKATAN BALANCED SCORECARD
Get PDFThe Schools have to anticipate the influence of external environments. The external environment analysis consist of the macro and micro analysis. The micro analysis used Porter`s five force model of competitiveness consist of threat of new entrans, the bargaining power of supplier, the bargaining power of customer, threat of substitutes schools and rivalry among existing schools. The purpose of this study was to examine the Porter`s five force model of competitiveness on organizational performance of school in balanced scorecard approach. Data for this study were collected from middle schools using a self-administered survey questionnaire. Hypothesis test showed that threat of new entrans, the bargaining power of supplier, the bargaining power of customer, threat of substitutes schools and rivalry among existing schools examined had a significant impact on school performance in balanced scorecard approach. but partially only threat of new entrans, the bargaining power of supplier, and rivalry among existing schools are significantly influence on schools performance in balanced scorecard approach. but for  the bargaining power of customers, and the threat of substitutes schools aren’t significantly influence on schools performance in balanced scorecard approach. Keywords: external environment, micro environment analysis, Porter`s five force model of competitiveness, performance, balanced scorecar
PENGARUH PEMASANGAN SIRIP PENGARAH PADA BUFFER TERHADAP UNJUK KERJA MOTOR BENSIN
Get PDFPerfect combustion can improve engine performance and save fuel consumption. One of the requirements perfect combustion is a homogeneous mixture of fuel and air when entering the combustion chamber. Air and fuel mixture to become homogeneous in case of turbulence in the mixing. Buffer with director fin is used to provide additional mixing time between air and fuel at the same time create a turbulent flow before entering the combustion chamber. In this study the buffer fitted with director fins with different variations. The number of fins variation used in this study are 3, 4, 6, 8 and 10 with a variation of the angle are 45o and 60o. The analysis was conducted on the effective power and torque output and the FC (Fuel Consumption) needed from each variation condition buffer. From the results of testing on the condition of the buffer with 3 fins angled 60o obtain the highest effective power increase 5.92% and increase in the highest torque 2.66% when compared with the buffer without fins. The lowest FC (Fuel Consumption) in the buffer with 3 fin angle 60 ° when compared with the buffer without any fins at 4000 rpm with a 11.15% difference. Keywords: homogeneous, turbulent, buffer and fi
PENGEMBANGAN DAN ANALISIS ERGONOMI KURSI OPERATOR MESIN VULKANISIR BAN DENGAN METODE REVERSE ENGINEERING
Get PDFThe likelihood of complaints occurring in the tire retreading machine operator is very possible especially if the seats are not as ergonomic. This situation occurs and will be redesign chair process machine operators with a method of tire retreading Reverse Engineering (RE) with respect to ergonomic aspects. By analysis using finite element software simulations, we can determine the voltage that occurs in part the concept of tire retreading machine operator seat. So it can be seen clearly the force distribution that occurs in material unit concept tire retreading machine operator seat. To calculate the material strength analysis by finite element software can use the help of CATIA V5R14 software. This is intended to get maximum results and an accurate analysis. After the experiment, the voltage that occurs on a cushion of 1.81x106 N/m2 located on the bottom face of the middle cushion while the minimum working voltage is 1.81x105 N/m2 located on the bottom front cushion edges. The voltage that occurs on a cushion of 1.27x108 N/m2 located at the base of the curved pipe connections while the minimum working voltage is 1.27x107 N/m2 located at the base of a straight pipe connection. Ergonomics analysis obtained by using the method Rula when operators run the machine has the injury risk rate value is 2, which shows the attitude of the body is acceptabel and do not need to be changed for the long term. Keywords: ergonomic, chair operator and reverse engineerin