Teknik Mesin

Synopsis Dalam aplikasi heat exchanger di lapangan banyak permasalahan yang masih ditimbulkan, misalnya panas yang ditransfer oleh heat exchanger belum maksimal, terjadinya penyumbatan pada bagian tube yang disebabkan oleh adanya korosi dan mengakibatkan terjadinya kebocoran pada tube heat exchanger. Hal ini berindikasi pada tingginya biaya perawatan. Untuk mengatasi permasalahan tersebut adalah dengan menganalisa mulai dari temperatur, tekanan, laju aliran serta pengujian kualitas oli dan air yang digunakan pada heat exchanger. Hal ini dilakukan untuk membandingkan data standar spesifikasi alat dengan aplikasinya dilapangan. Kebocoran pada heat exchanger, menyebabkan perusahaan shutdown diluar schedule yang telah direncanakan dan terhentinya produksi, sehingga menimbulkan kerugian yang cukup besar. Agar kasus seperti ini tidak terulang lagi dimasa yang akan datang maka perlu dilakukan analisa kegagalan terhadap kasus ini. Dalam hal ini, masalah yang dikaji adalah : menganalisa mulai dari temperatur, tekanan, laju aliran serta pengujian kualitas air dan oli pada heat exchanger. Heat exchanger merupakan objek utama dalam penelitian ini. Penelitian dimulai dengan mempelajari spesifikasi dari heat exchanger yang digunakan saat ini. Hal ini dilakukan sebagai acuan atau batas standar yang diijinkan oleh alat tersebut. Penelitian dilanjutkan dengan pengambilan data temperatur, tekanan dan laju aliran pada sisi inlet dan outlet heat exchanger. Pengambilan data dilakukan pada pagi dan sore hari secara konstan, ini dilakukan untuk menganalisa apakah ada pengaruh temperatur lingkungan saat pengambilan data. Pengambilan data dilakukan sebagai pembanding data fakta yang terjadi dilapangan dengan standar dari alat tersebut. Setelah data didapatkan kemudian dianalisa untuk mendapatkan hasil performa heat exchanger dan setelah itu dibandingkan dengan data standar dari heat exchanger agar mengetahui kemungkinan penyebab kegagalan.

Abstract: This study sheds light on the materials (elastomers) which are used for buffer equipment production. One of the unsolved problems concerning shock absorption is the problem of optimal material choice for the shock absorber. It is the main problem examined in this study. We conclude that the material should be chosen in accordance with such characteristics as energy intensity rate, internal friction and rheological characteristic.

Produk yang dihasilkan dari proses produksi mempunyai ragam atau variasi. Proses duplikasi produk dengan sempurna tidak akan dicapai, melainkan hanya mungkin dihasilkan produk yang berbeda-beda karakteristiknya. Hal ini menuntut perancang produk mempunyai kesadaran bahwa suatu toleransi harus diperhitungkan pada waktu spesifikasi produk ditetapkan. Memberikan toleransi berarti menentukan bata-batas maksimum dan minimum dimana penyimpangan produk harus terletak. Dalam hal spesifikasi geometrik mencakup toleransi atas ukuran, bentuk, posisi serta kekasaran permukaan produk.

Recently reducing emissions of the harmful gases that generated in the combustion process of the automobile and other internal combustion engine is absolutely essential to environmental preservation. These emissions pollute the environment and contribute to the global warming, acid rain, smog, odours, and respiratory and other health problems. Therefore many countries around the world are taking major efforts to toughen emission standards. Motor cycles, the lagers amount, contributed the major air pollution in Indonesia. The hamful gases that generated in the motor cycles especially CO, HC and NOx . As the motor cycles is getting older, many components in the combustion system are getting worst and contribute more hamfull emissions.
This research was done on July 2001 to find out the emissions and was done on Honda Astrea Grand which have been used since 1995, 1996 dan 1997 on the variety of gear level. A multigas analyser was used to analyse the emission gas out form the tile pipe.
The result shows that the maximum CO and HC emission are generated by all motor cycle on the first gear. The higerst CO and HC emission is generated by the olderst motor cycle (1995) and the minimum CO and HC emission is generated by the motor cycle that has been used since 1997.

The heat transfer is important in engineering field and aspects of the life. Many equipment was made by using principles of the heat transfer, like: the oven, iron, the car machine, the muffler, the room cooler et cetera. The principle of the work in the research, there was the heat source at the upper side and the sink (heat remover) at the bottom side so that the temperature different (was significant) along metal that was tested. The heat source from the electric heater, the object the test togethered with his heater all was isolated. The test object consisted aluminum with 20 mm2 cross section area, the steel and copper have 10 mm2 cross section area. The results that that the conductivity of copper was biggest were followed with aluminum and finally the steel.

Cow manure can be used as a source of energy and as a solid or liquid fertilizer. An adult cow can produce fases (solid manure) to 23 kg/day and urine (liquid manure) 9 kg/day. Three or four cow is capable to fullfill the dayly needs of cooking fuel for one rural household. Cow manure slurry can also be convert as fertilizer, that is liquid fertilizer which is derived from urine and solid fertilizer originating from the solids. Solid and liquid from cow manure is usually mixed, therefore to make the liquid and solid fertilizer, the liquid and solid masses need to be separated first. Recent separators of fases and urine are are electrical energy driven, so that those kind of device could not be used in the rural areas where the electric grid supply were not available. So that a model of a faces-urine separator of cow manure slurry is utilize which was constructed for manual pressing force. Moreover, through this research It have had created a manual fases-urine separator which only requires one operator. The separator consists of main parts including; lever press, chamber press, fases-urine separation mechanism, the mechanism of loading-unloading, and ajustment mechanism for pressing pressure. This design is capable of performing the separation in a wide range of pressing force and it only requires one operator. Results Show That the model is capable to separate liquid from the slurry as much as 13.9% at a pressing force of 14 kg the which is applied for 18 seconds.

Cultivation activities, both in the development of food crops, horticulture, livestock and plantations. Availability of water is a strategic factor. Specific areas adjacent to the water source or location are under the eyes water, water needs are less of a problem. However, the ground reality is not always flat; there is the hilly or bumpy. Land surface area is higher than the water source and the bumpy areas will have trouble getting a continuous supply of water. Therefore need to find an alternative to reduce the burden. One alternative is that hydram pump hydraulic work without using gasoline. Hydram pump was applied to a small debit them to raise water and drinking water needs of households. However, the use for irrigation in dry land agriculture that requires a large output flow is unknown. The method used in this research is to create models in the laboratory to simulate the independent variables of pressure (high falling) water flow while bound variables measured include debit and results of hydraulic pressure. The results of experiments that analyzed the correlation between independent variables and the variables are bound to get hydram pump efficiency. Pumps that were realized and tested in the laboratory have the following specifications: input = 1.5 inch diameter; output diameter = 0.5 inches; step on the valve piston waste = 5 mm; air tube diameter = 3 inches; air tube length = 24 cm ; material with galvanized pipe, construction of hydram pump consisting of the first arrangement of input-waste valves-compressor (ILK) and the second arrangement of input-compressor-waste valve (IKL). Pump of hydram with arrangement ILK has the ability to better performance when compared with the composition of IKL. Where pump of hydram with the composition of ILK has the best efficiency at 2.5 meters high waterfall with a debit enter 2.458 liters / sec discharge output capable of being lifted by a pump at 0087 liters / sec while the high lift or vertical height of the pump which is equal to 30 meters and efficiency pump of hydram which is equal to 13.6%. Keyword : hydram pump, valve waste, air tube, arrangement of pump, peformance

It has been conducted on the effect of ion implantation of TiN to wear ball bearings with grease lubrication. Ball bearing is one of the supporting components contained in the machine and the parts of a rotating element as found in automotive components. During the operation, this component causes the surface wear and vibration caused by continuous movement during loading. Ion implanted TiN ball bearing at the time of 90 minutes, the energy of 100 keV and current 10 μA are ring inside the outer ring, and ball as the wear test samples. Tests carried out with 3 variations of wear load and 3100 rpm shaft rotation. Grease is used to mark the torch. Then 3.9 grams of grease in then applied to the outer ring, inner ring and the ball. The test results showed that the wear volume increased with increasing the load on ball bearing non-implantation with grease lubrication, while the ion implanted TiN almost no increase. Wear resistance increased in metal ion implanted TiN. It is characterized by decreasing in wear rate when compared with non-metal implants. And traces of scratches experienced a very significant reduction in metal ion implanted TiN.

This research to investigate the effect of Pomacea Canalikulata Lamarck powder addition in the process of carburization box to physical (microstructure) and mechanical properties (hardness test) of AISI 1018 after heat treatment. In this research used a material of low carbon steel cylinder (AISI 1018). The process of making the specimen is done with to cut into several pieces, cutting done to ease in placing the specimen in the carburizing box, then wood charcoal powder and shell powder were weighed in accordance with the desired composition by mixing powder of 5 wt%, 10 wt%, and 15 wt%. The specimen was done heat treatment at a temperature of 950 0 C with the holding time at 2, 4 and 6 hours. Then, the specimen was done the Vickers hardness test, microstructure and composition test. From this research it can be concluded that the highest hardness value was obtained at 15 wt% addition of shell powder it was 262.26 kg/mm 2 and the initial material hardness value was 144.08 kg/mm 2. From microstructure observation and composition test show that it subjected surface hardening because carbon diffusion into specimen. ABSTRAK Tujuan dari penelitian ini adalah untuk mengetahui pengaruh penambahan serbuk cangkang keong emas pada proses pack carburizing terhadap sifat fisis (struktur mikro) dan mekanis (uji kekerasan) baja karbon rendah setelah mengalami perlakuan. Bahan yang digunakan dalam penelitian ini adalah baja karbon rendah yang berbentuk selinder. Proses pembuatan spesimen dilakukan dengan pemotongan menjadi beberapa bagian, pemotongan dilakukan untuk memudahkan di dalam meletakan spesimen di dalam kotak karburisasi,kemudian serbuk arang kayu dan serbuk cangkang ditimbang sesuai dengan komposisi yang diinginkan dengan pencampuran serbuk cangkang 5, 10 dan 15 (% berat). Spesimen dilakukan perlakuan panas pada temperatur 950 0 C dengan penahanan waktu selama 2, 4 dan 6 jam. Kemudian dilakukan Uji kekerasan Vickers, pengujian foto struktur mikro dan uji komposisi. Dari penelitian ini dapat disimpulkan bahwa nilai kekerasan tertinggi rata-rata pada penambahan 15% serbuk cangkang di peroleh sebesar 262,26 kg/mm 2 dan kekerasan material awal diperoleh sebesar 144,08 kg/mm 2. Dari hasil pengamatan struktur mikro dan uji komposisi diketahui bahwa terjadi pengerasan permukaan karena difusi karbon kedalam baja karbon randah. Kata Kunci : Cangkang keong emas, pack carburizing, uji kekerasan, uji komposisi, struktur mikro

Fuel quality had a major effect on improvement of the engine performance. One of the reason is the engine performance to get off is detonation occurs in the combustion chamber. To support this effort is by using high octane fuel as Pertamax. By using those fuel, it is expected to economize the fuel consumption and reduces air pollution level. There by the improvement of the engine performance is expected to be happening. This research was done to analyse the effect of premium and pertamax consumption in terms of torque, effective power and specific fuel consumption effective (SFCe) on Daihatsu Feroza engine 1589 cc. The instrument for measuring the torque of engine were trommel and brake power system by using brake material that adopts brake prony system. The experiment was done at wide open throttle (WOT) at fourth transmission at 1600 rpm, 2100 rpm, 2600 rpm, 3100 rpm, and 3600 rpm. The experiment result was gained maximum of torque, effective power and specific fuel consumption effective (SFCe) to premium gasoline RON 88 at 3600 rpm severally is 12,92 Kg.m, 64,93 PS and 0,10 L/PS.jam and to pertamax gasoline RON 92 severally is 13,52 Kg.m, 67,97 PS and 0,09 L/PS.jam. Average increasing of torque and effective power equal to 6,52% and 6,79%. While the average degradation of spesific fuel consumption effective (SFCe) equal to 16,18%.

The development of composite materials in the field of engineering is increasingly being used. This is because of its properties are superior compared to conventional materials, as the ratio between strength and density are quite high, stiff, the manufacturing process is very simple and resistant to corrosion and fatigue loads. The purpose of this study was to determine the effect the addition of nylon fibers with Epoxy Matrix on the increase in bending strength of epoxy composites. The objected of this study was the composite of nylon fiber, which is cut 12 mm nylon fiber with epoxy resin as a fastening material. Before performing an experiment testing the tensile fibers has done and known to the stress of 461.22 MPa. There are 3 variations of volume fraction In this experiment, those are volume fraction of 40%, 50% and 60%, with 3 variation each. Method in the manufacture of specimens with the way the mould press. Tools to test the specimen is bending test machine (servopulser). Specimens using a standard test of ASTM C 393-94. Bending test results showed that the nylon fiber composite with fiber volume fraction 40% stress of 787.16 MPa, modulus of elasticity of 1.06 GPa, volume fraction of 50% the stress of 902.01 MPa, modulus of elasticity of 1.08 GPa, and for 60% volume fraction of the stress of 950.02 MPa, modulus of elasticity of 0.99 GPa.

Producing biodiesel by dry method has been conducted in the Laboratory of Energy Conversion, Mechanical Engineering Department, Mataram University. In the conventional method, coconut flesh is scrabbed and then squizzed to separate the coconut milk then from this milk obtained oil. In dry method, the flesh is cut in to small pieces then cook in the sealed container.Its vapor is collected , condensated and eventually oil is produced.By transesterification process biodiesel is obtained. The combination of metanol : coconut oil is varied as follow :10 (K0), 1:10 (K10), 2:10 (K20), dan 3:10 (K30). Biodiesel produced is then tested to evaluate its specific gravity,kinematic viscosity,flash point and calorifiec value.The result show that increased methanol concentration reduced specific gravity,kinematic viscosity,flash point and calorifiec value. Specific gravity for K0, K10, K20, and K30 in the transesterification process are 0.864, 0.851, 0.849, and 0.843, respectively. Kinematic viscosity for K0, K10, K20, and K30 are 5.65 mm 2 /s, 4.80 mm 2 /s, 4.29 mm 2 /s, and 3.52 mm 2 /s, respectively. Flash point for K0, K10, K20, and K30 are 62.33 0 C, 58.67 0 C, 54.67 0 C, and 52 0 C. Calorifiec value for K0, K10, K20, and K30 are 19601.842 Btu/lb, 19105.375 Btu/lb, 17803.337 Btu/lb, and 16548.844 Btu/lb.

Experimental testing using coconut oil produced by dry method on engine has been conducted in the Laboratory of Energy Conversion, Mechanical Engineering, Mataram University. The purpose was to evaluate the effect of using this coconut oil on the engine performance. The oil was mixed with diesel oil in order to obtain biodiesel. There were four combinations of ratio diesel oil to coconut oil; namely 100% : 0% (mkp0%), 90%:10% (mkp10%), 80%:20% (mkp20%) and 70%:30% (mkp30%.). Mitsubishi L300 diesel engine was used in this experiment by variating engine speed 1000 rpm, 1050 rpm and 1100 rpm with torgue load at 1 kg. At engine speed of 1200 rpm the loads were varied as 1 kg, 1.5 kg and 2 kg. The result shows that by increasing the number of coconut oil in the mixture will reduce engine fuel consumption. Fuel consumption of the mixture will be better compare to the fuel consumption of pure diesel oil. Specific fuel consumption efective (SFCe) of coconut oil-diesel mixture at mkp 10%, 20% and 30% are lower than of pure diesel oil. The reduced SFCe are 1.45 %, 1.71% and 3.57 % at effective power 0.838 PS, 1.98%, 4.31% and 4.31% at effective power 1.257 PS and 1.22%, 3.92% and 7.12% at effective power 1.676 PS. By varying the engine speed, the result also shows that SFCe of the mixture is also lower than SFCe of pure diesel oil.

Abstrack Solar energy constitute one of potential alternative energy to develop as a back up of energy. Especially for countries in khatulistiwa location belonging to Indonesia. For use solar energy needful collector that using absorber. Using sand as a absorber make up step for increase value and profit of sand, in a economics manner the price more cheap and easy to obtain than another absorber. The analysis use sand as a alternative absorber for solar collector did for understand rate of heat transfer to acceptanceof water. Dimention of collector are 560 mm x 310 mm with thick of sand absorber 10 mm and 1.2 mm for aluminum plate as a comparator. Observation did begin 10.00 am until 14.00 pm for the two of them in the weather clear sky. The rate of water in this research are 200 cc/min, 250 cc/min and 300 cc/mn for another dan at the same time. The result of analysis be obtained heat absortion by water for solar collector with aluminum absorber more large than sand absorber. The debit of water more and more large in the collector so absorb heat by water more large because incretion the mass flow rate of water (m ). The heat losses in the solar collector aluminum absorber more than sand absorber.

The purpose of this study is to investigate the influence of fiber volume fraction of the impact strength of palm fiber-unsaturated polyester composite and investigate the mechanism of fracture caused by impact loads. This research material is palm fiber (Arenga pinnata), unsaturated polyester matrix yukalac BQTN-EX 157 type, hardener metyl etyl ketone peroxide (MEKPO), alkali solution (NaOH) and H2O. Testing with Charpy impact tester, impact test specimens prepared according to standard test ASTM D-5942. While the macro picture is used for the analysis of the fracture. The results showed that the most optimum impact toughness of palm fiber-polyester composite reached 0.011 J/mm 2 on volume fraction (Vf) 40%. While the interaction characteristics of palm-fiber bond strength polyester showed matrix cracking behavior of failure on volume fraction (Vf) 10% to 30%, and fiber pull out the volume fraction (Vf) 40% and 50%, the same fracture behavior between the matrix and fibers in volume fraction (Vf) 40% indicates that fiber and matrix has a strong bonding interaction.

The aim of this study is to investigate the effect of shot peening on stress corrosion cracking of a low carbon steel in ocean water environment. The dimension of specimens were prepared in accordance with the ASTM G39. The hardness testing was carried out using microvickers with 0,25 kgf load in the longitudinal direction. The corrosion cracking test was immersed into artificial sea water for about 7 months. The test shows that the pitting corrosion is dominantly nucleated at the metal film interface. The biggest pitting corrosion was occurred under the static loading of 70 for the specimens unpeened. The presence of pitting corrosion promotes stress corrosion cracking. The cracking has a intergranular branched morphology which is typical for the chloride cracking of low carbon steel

Refrigerant in refrigeration machines will absorb heat from a room space and released the heat to the environment. The heat balancing in the system is heat released from condenser equal with heat absorbed from room space added by the heat equivalent from compressor work. Based on this heat cycle, the writer try to conduct research on using this heat rejection from condenser to heating tap water, focusing on water flow rate increased from 0.5 liter/min to 2.5 liter/min. From experiment and analysis result obtained that the maximum heat water temperature which can be reached is 47.5°C in 0.5 liter/min, with the equipment specifications are 2 HP-split air conditioning and the tank volume is 75 liters. The additional result is heating water temperature is fallen when the water flow rate is increased.