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Abstrak :
Telah dibuat suatu sistem rancang bangun sebuah alat untuk pengujian suatu metode dalam percobaan tumbukan dengan menggunakan sistem jalur udara atau air track. Sistem ini dirancang dengan tujuan agar dapat mempermudah dalam mengetahui suatu metode fisika khususnya teori tumbukan. Dalam sistem ini tidak hanya teori tumbukan saja yang berperan melainkan juga teori kekekalan momentum dan juga gaya gesek cukup memeberi andil yang besar dalam sistem ini. Dalam perkembangan teknologi saat ini teori mengenai tumbukan sangat penting guna kemajuan teknologi untuk saat ini dan masa yang akan datang. Dalam tugas akhir ini, akan diaplikasikan metode tersebut dimana akan digunakan dua buah benda uji yang akan saling bertumbukan satu sama lain sehingga akan dihasilkan efek lenting dari proses tumbukan tersebut ......Have been made a system design and deverlopment to a appliance for the examination of collison method by using air band system or airtrack . This system is designed with a purpose to be can water down in knowing a physics method specially collison theory. In this system do not only just collison theory which sharing but also conservation of momentum theory as well as style fiddle enough big share to give in this system. In technological growth in this time theory concerning collison of vital importance utilize technological progress to in this time and a period of to come. In this final duty, method application will be the where will be used by two test object to is knocking against each other one another so that will be yielded by effect dash away from collide process

Abstrak :
Kompresor pada bus listrik digunakan pada bagian sistem pendingin bus tersebut dimana kompresor dikopel dengan motor induksi. Suhu ruangan pada bus listrik tergantung dari bagaimana kita mengendalikan kecepatan motor induksi tersebut untuk memutar impeller blade yang terdapat di dalam kompresor agar refrigerant dapat disalurkan menuju kondenser dan menurunkan suhu ruangan. Untuk dapat menerapkan sistem ini, dibutuhkan inverter sebagai pengubah daya listrik yang bersumber dari baterai DC 400 V menjadi listrik AC 3 fasa. IGBT switch yang terdapat pada inverter menerima sinyal masukan berupa pulsa ON dan OFF yang dihasilkan melalui metode Sinusoidal Pulse Width Modulation (SPWM) untuk menghasilkan tegangan 3 fasa. Tegangan tersebut akan divariasikan untuk mengendalikan kecepatan motor induksi dengan menggunakan metode pengendalian vektor medan rotor Rotor Field Oriented Control (RFOC) dan pengendali PI. Pengendali suhu refrigerant akan menjadi outer loop dari sistem ini dengan menggunakan pengendali IP. Dengan menggunakan metode seperti ini, dapat disimulasikan pengendali kecepatan motor induksi untuk mengendalikan suhu gas pendingin pada sistem pendingin. ......The compressor on the electric bus is used on the part of the bus cooling system where the compressor is coupled with an induction motor. The room temperature on an electric bus depends on how we control the speed of the induction motor to rotate the impeller blade inside the compressor so that the refrigerant can be channeled through the condenser and lowering the room temperature. To be able to implement this system, an inverter is needed as a power converter that convert a 400 V DC battery source to 3 phase AC electricity. IGBT switches inside the inverter receive input signals in the form of ON and OFF pulses generated through the Sinusoidal Pulse Width Modulation (SPWM) method to produce 3 phase voltages. The voltage will be varied to control the speed of the induction motor using the Rotor Field Oriented Control (RFOC) method and the PI controller. The temperature controller of the refrigerant will be the outer loop of this system using an IP controller. With this method, the simulation of induction motor speed control for temperature control of cooling gas system can be made.

Abstrak :
Sistem Ruang Tata Udara merupakan proses yang menggabungkan kontrol dan menjaga tingkat suhu, kelembapan, pergerakan udara, kebersihan udara dan perbedaan tekananan dalam ruang yang berstandar kenyamanan bagi pengguna dalam ruang yang dikondisikan. Definisi dari kenyamanan termal ialah menyediakan penghuni dengan lingkungan dalam ruangan yang nyaman dan sehat untuk melakukan aktivitas mereka. Chiller plant sebagai unit pendingin udara sentral memiliki fungsi untuk membuang panas yang diambil dari ruangan yang dikondisikan menuju air yang sudah didinginkan melalui pompa, pipa, dan katup. Chiller plant terdiri dari chiller, pompa (in dan out), dan cooling tower. Chiller sendiri terdiri dari beberapa bagian yaitu, evaporator, kondeser, katup ekspansi, dan kompresor. Efisiensi (kW/TR) yang tinggi sangat dibutuhkan dalam chiller plant untuk mencapai hasil pendinginan yang maksimal serta pengeluaran anggaran yang minimal. Terlepas dari efisiensi, kerja (COP) dari masing – masing kompresor juga harus diperhatikan kesesuaiannya terhadap standar nasional (SNI) maupun standar internasional (ASHRAE). Efisiensi dari chiller plant (kW/TR) yang dihasilkan masih belum memenuhi standar, namun kerja kompresor dari masing-masing chiller sudah mengikuti standar yang ada. ...... Air Conditioning System is a combined process that performs controls and maintains the temperature, humidity, aur movement, air cleanliness, and pressure differential in a space within a comfort standard for occupants of the conditioned space. Definition of Thermal Comfort have to provides occupants wtih a comfortable and healty indoor environment in which to carry out their activities. Chiller plant as a central cooling air unit has function of rejects the heat extracted from the condtioned space to the chilled water that distributed via pumps, pipes, and valves. Chiller plant consist of chillers, pumps (in and out), and cooling towers. The chiller itself consist of several parts, evaporator, condenser, expansion valve, and compressor. Efficiency (kW/TR) is needed in the chiller plant to get maximum results and minimum expenditure. Regarding efficiency, the peformance (COP) of each compressor should also consider its compliance with national standards (SNI) and internasional standards (ASHRAE). The efficiency of chiller plant (kW/TR) still does not meet the standard, although the work of the compressor of each chiller has followed the existing standards.

Abstrak :
Unjuk kerja dari blade kaskade sangat dipengaruhi oleh perkembangan dan pemisahan boundary layer pada permukaan blade dan end wall (casing dan hub). Aliran sekunder yang terjadi dekat casing dan hub tersebut merupakan fenomena separasi aliran 3D yang mengakibatkan adanya secondary losses, blockage effect, dan turning angle distribution (deflection) sepanjang span yang akan merugikan kinerja dari kompresor aksial. Hasil penelitian menunjukkan bahwa dengan pembebanan yang semakin besar maka terlihat adanya garis-garis tekanan konstan menjadi semakin melengkung ke arah upstream atau memperlihatkan terjadinya kenaikan tekanan statis sepanjang span akibat curl flow yang semakin kuat. Garis separasi juga semakin kuat dan membentang diantara dua sudu. Akibatnya daerah separasi 3D di sudut juga bertambah besar.

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Secondary Flow Experimental Study for Axial Compressor Cascade Strong Stagger With and Without Tip-Clearance: Static Pressure Distribution on Blade Surface. The performance of blade cascade is influenced by the growth and boundary layer?s separation along blade surface and endwall (casing and hub). The secondary flow which happens near hub and casing compressors is three dimentional flow separation phenomenon comes from interaction blade boundary layer with casing and hub boundary layers in the compressor. The secondary flow causes secondary losses, blockage effect, and turning angle (deflection) distribution along blade span. The result of the research shows that the increase of the angle of attack reveals lines of constan pressure to be curved forward (upstream) or pressure gives rise to spanwise caused by a strong curl flow. Separation is also increase and cross between two blades. Hence, three dimentional separation region in corner also increase.

Abstrak :
Kegiatan Risk Assassement menjadi bagian penting dari upaya pengoptimalan kinerja dan kehandalan dari suatu sistem selama operasi. Dengan demikian dibutuhkan pendekatan Risk Assassement yang sesuai untuk menilai resiko yang terjadi. Pada penelitian ini menggunakan pendekatan FMECA dan simulasi Monte Carlo (Crystall Ball) dalam proses menilai resiko. Hasil dari Risk Assassement menggunakan FMECA menunjukan bahwa peralatan yang mempunyai nilai prioritas paling tinggi (RPN) serta memiliki resiko tinggi adalah pada sub system Scrubber, Kompresor, serta gas turbin. Sementara hasil simulasi Monte Carlo menunjukan bahwa hanya sub system kompresor dan gas turbin yang mempunyai resiko tinggi. ......The risk assessment activity becomes an important part of the effort of a system performance and reliability of a system during operation.Thus, it takes appropriate Risk Assessment approacth to assessing the risk. In this study, Monte Carlo and FMECA method are used in the process of assessing risk. The risk assessment result based on FMECA analysis show that the equipment have risk priority number as well as high risk are scrubber,compressor and gas turbin.while by Monte Carlo Method show that only compressor and turbin gas that have highest risk.

Abstrak :
ABSTRAK
Potensi penurunan produksi pada lapangan gas ditandai dengan penurunan tekanan secara alamiah yang merupakan indikator dari lapangan yang sudah tua (mature), seperti yang dialami oleh Lapangan Gas X sehingga perlu dilakukan optimasi produksi untuk menyesuaikan dan memberikan strategi manajemen reservoir gas agar produksi gas dapat berkesinambungan sampai akhir kontrak wilayah kerja Blok Sengkang. Optimasi produksi yang akan dilakukan adalah pemasangan gas compressor dan infill drilling yang ditentukan untuk mencari skenario terbaik pengembangan lapangan gas yang dievaluasi teknis dengan analisis sistem produksi dan evaluasi keekonomian hulu, sehingga skenario yang terpilih diharapkan memberikan kemampuan penyaluran gas kepada pembeli secara berkelanjutan. Diharapkan skenario optimasi produksi tersebut mampu mencegah potensi kerugian yang akan datang pada perusahaan guna mempertahankan volume penyerahan gas yang sesuai dengan kontrak demi menjaga pendapatan perusahaan maupun pemerintah

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ABSTRACT
Potential decline in production at gas fields marked with a pressure drop naturally which is an indicator of the field are mature, as experienced by the X Gas Field that needs to be optimized in production to adjust and provide the strategies of gas reservoir management so that gas production can be sustainable until the work area contract of Sengkang Block end. Production Optimization that will be applied is the gas compressors installation and infill drilling is determined to find the best scenario of gas field development which is evaluated by the production systems analysis and the upstream petroleum economics, so that the chosen scenario is expected to provide a gas supply ability to buyers in a sustainable manner. A scenario of production optimization is expected to be able to prevent the potential losses that will come in the company in order to maintain the gas delivery volume in accordance with the contract in order to maintain the revenue of company and government

Abstrak :
Numerical analysis has been performed of time-space structures in a large turning angle axial cascade subject to unsteady incoming wake exciation....

Abstrak :
In this cooling process will be conducted research on drinking water, how long it will be cooled by the refrigerator, which is placed beside the bottom of the tube drinking water, to achieve a relatively low temperature and the amount of heat absorbed by the refrigerator of drinking water. All parts of the outer tube so that the hot water is isolated from the outside only a few enter into the drinking water, which amount will be calculated during the cooling process. In this cooling process, when the water has reached the specified conditions, the cooling machine will stop automatically. In this cooling process, the research methods that will be used is an experimental method, wherein the temperature of the water is the independent variable that will be determined later. And from these tests can be concluded that in the cooling process for 35 minutes obtained by the heat released from the drinking water is (105.84 kJ) and the added value gained heat into water (0,313 Watt) or (0.0869) Kj/h.

Abstrak :
Electric car is one technology that is designed to reduce the risk of pollution that causes global warming but an air conditioning system is required to create thermal comfort for its users. Therefore national electric car (MOLINA) made by the University of Indonesia will use BLDC compressor for the air conditioning system. Cooling load calculation is required to design the air conditioning system. This research will calculate the cooling load of MOLINA UI and also select the compressor that will be used in the air conditioning system. Then, the air conditioning system that has been designed and built will be tested for its performance. In the performance test, temperature and flow velocity of MOLINA air conditioning duct will be measured. Then proceed with simulation of temperature distribution and air flow in MOLINA cabin. Moreover, the energy consumption of MOLINA air conditioning systems that is using a BLDC compressor will also be measured. Based on this research it is known that the value of the cooling load on MOLINA UI is 2894.12 Watt (9875.15 BTU/h), average energy consumption of air conditioning systems MOLINA UI without inverter is ranged about 540 to 857.3 Watts and efficiency of inverter is ranged about 84.7% to 89.4%.