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"Pengembangan kendaraan penumpang dewasa ini diperlukan untuk menjamin bahwa kendaraan yang dirancang dan dibuat untuk penumpang memenuhi unsur performa maupun keselamatan. Namun, dengan besarnya industri otomotif yang dimiliki negara lain, memunculkan ide untuk perancangan dan pembuatan platform chassis sesuai dengan pasar Indonesia yang mengandalkan performa yang kuat dan tetap memiliki konsumsi energi yang rendah. namun dengan memenuhi unsur kandungan lokal yang sangat tinggi serta memenuhi unsur performa yang menjamin kenyamanan serta keselamatan penggunanya. Rangka semi monokok merupakan platform rangka yang ideal untuk diterapkan di Indonesia. Perancangan dan pembuatan rangka yang dipergunakan sangat tergantung dari material yang digunakan, bentuk rancangan, maupun sambungan antar seksi penyusun dari rangka tersebut. Dengan menggunakan perhitungan analitik dan simulasi serta pengujian eksperimen, dapat disimpulkan performa dan keselamatan dari rangka yang dirancang dan dibuat untuk kemajuan bangsa Indonesia.

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Development of passenger car needs to be sure that the car which designed and manufactured fulfill the performance and safety indicator. But, with huge automotive industry which owned by another nation, rising the idea of designing and manufacturing chassis platform according to Indonesian market which need highly performance and low cost in energy usage, but having high content of local material and fulfill the performance indicator that ensure comfort and safety of the users. Semi Monocoque Chassis is the most ideal chassis to be used in Indonesia. Designing and manufacturing the chassis depends on the material, design, and the joint between car section. With using analitycal, simulation and experiment calculation, it can conclude the performance and safety indicator of the chasiss which designed and manufactured for the development of Indonesian Republic."

"Serangkaian Investigasi komputasional 3 Dimensi dan eksperimental dilakukan untuk menganalisa pengaruh kontrol aliran aktif berhubungan dengan usaha pengurangan nilai koefisien drag aerodinamika pada Makara Electric Vehicle MEV Untuk mengurangi drag ini model uji dilengkapi oleh dua buah aktuator kontrol aliran jet sintetik yang diletakkan simetris terhadap sumbu tengah dari model pada atap bagian belakang model Tahap Pertama Pengukuran terhadap gaya drag aerodinamika dilakukan dengan mengguakan load cell pada terowongan angin Tahap selanjutnya hasil eksperimen di verifikasi secara teoritis dengan metode numerik menggunakan perangkat lunak CFD Ansys Fluent Penggunaan jet sintetik pada MEV dengan 3 kecepatan upstream berbeda yaitu dan dapat mengurangi ukuran olakan yang terjadi pada sisi belakang model uji meningkatkan tekanan statik dan menurunkan persentase intensitas turbulensi Pada kasus ini 2 metode penelitian yang digunakan menunjukkan bahwa nilai pengurangan hambatan aerodinamika lebih besar terjadi ketika kecepatan upstream aliran udara lebih tinggi.

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An array of 3D computational and experimental investigation are conducted to analyze the effect of the active flow control to reduce aerodynamic drag on the Universitas Indonesia electric car model Makara Electric Vehicle MEV In order to reduce this drag two synthetic jet actuators are laid down symmetrically from the centerline of the lateral direction on rear end roof of the model In the first instance drag force measurement of the model is undertaken using a load cell on a wind tunnel for two different upstream velocities and Secondly The simulation was carried out in ANSYS FLUENT to verified the experimental result Synthetic jets affects on a reduction of the near wake section and turbulence intensity of air flow behind the model It also increase the static pressure of air flow behind the model This control leads to a slightly drag reduction on the model In this case two research methods yield the more drag reduction on the higher upstream velocity of air."

"ABSTRAKNaskah ini bertujuan untuk mengetahui performa sistem chiller pada pengoperasian ruang auditorium di Gallery Art Centre, Universitas Indonesia, sekaligus memverifikasi desain sistem. Instalasi sistem chiller berbasis refrigeran alami merupakan yang pertama untuk institusi perguruan tinggi di Indonesia yang juga merupakan bagian dari usaha green campus movement. Sistem pendinginan dengan memanfaatkan jenis refrigeran yang memiliki nilai ODP dan GWP rendah saat ini menarik perhatian dalam hal riset dan implementasi untuk menggantikan penggunan refrigeran R22. Dari hasil pengujian didapatkan COP rata-rata maksimum 4.27 pada kondisi pembebanan kosong, dan 5.25 saat pembebanan parsial. Kapasitas pendinginan maksimum kondisi tanpa pembebanan dan pembebanan parsial adalah masing-masing 125.93 kW dan 148.39kW, dengan konsumsi daya 30.06 kW and 30.12 kW.

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ABSTRACT<>br>The purpose of this paper is to examine energy efficiency through the study of performance in vapour compression cycle for auditorium in University of Indonesia using natural refrigerant R290. The installation of the chiller system which is the first in Indonesia within academic institution is particularly relevant in light of the gaining interest and research regarding the implementation of refrigeration system utilizing relatively low ODP and GWP refrigerant as alternative to replace the refrigerant R22. It is found that the maximum average COP is 4.27 at free load and 5.25 at partial load. The cooling capacity are 125.93 kW with energy consumption of 30.06 kW during free load and 148.39 kW with energy consumption of 30.12 kW at partial load, respectively."

"[ABSTRAKMaterial Bake Hardening merupakan material yang memiliki sifat mudah dideformasi sebelum diberi perlakuan panas dan sulit dideformasi setelah diberi perlakuan panas. Material ini merupakan material baru yang digunakan pada industri otomotif untuk digunakan pada kerangka mobil dan badan mobil. Material ini akan disambungkan menggunakan mesin Resistance Spot Welding. Resistance Spot Welding merupakan salah satu jenis pengelasan yang banyak digunakan di industri otomotif. Penelitian ini bertujuan untuk mengetahui pengaruh dari parameter kuat arus dari mesin resistance spot welding pada material bake hardening. Penyambungan material bake hardening ini dilakukan dengan menggunakan mesin resistance spot welding dengan pemberian kuat arus 8kA, 9kA, 10kA, 11kA dan 12kA. Pengujian yang dilakukan antara lain pengujian kekerasan, geser, pengamatan SEM, dan metalografi. Hasil penelitian menunjukkan bahwa kekuatan optimum yaitu 5,68kN dan kekerasan optimum yaitu 237,34 VHN didapat pada sampel yang diberi kuat arus sebesar 11kA. Pemberian kuat arus diatas 11kA akan menyebabkan penurunan pada kekuatan dan kekerasan. Pola penjejakan kekerasan menunjukkan bahwa daerah nugget memiliki kekerasan yang lebih tinggi dibandingkan base metal. Struktur mikro juga menunjukkan bahwa semakin ke daerah nugget, butir semakin membesar dan fasa bainite bertambah banyak.

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ABSTRACT

Bake Hardening material is a material that is easily deformed before being given a heat treatment and become a hard deformed after being heat-treated. This material is a new material used in the automotive industry for car frame and car body. This material will be welded using Resistance Spot Welding machine. Resistance Spot Welding is one type of welding that is widely used in the automotive industry. This study aims to determine the effect of the current welding parameters of resistance spot welding to bake hardening material. The joining of bake hardening material is performed using resistance spot welding machine with current 8kA, 9kA, 10kA, 11kA and 12kA. Tests performed include hardness testing, shear, SEM and metallography. The results showed that the optimum tensile strength is 5,68kN and optimum Vickers hardness is 237.34 VHN samples were obtained at a current of 11kA. Giving current 11kA above will cause a decrease in tensile strength and Vickers hardness. Hardness distribution of Vickers hardness shows that nugget area has a higher hardness than the base metal. Microstructure also shows that the area to the nugget, grain growing and increasing bainite phase.;Bake Hardening material is a material that is easily deformed before being given a heat treatment and become a hard deformed after being heat-treated. This material is a new material used in the automotive industry for car frame and car body. This material will be welded using Resistance Spot Welding machine. Resistance Spot Welding is one type of welding that is widely used in the automotive industry. This study aims to determine the effect of the current welding parameters of resistance spot welding to bake hardening material. The joining of bake hardening material is performed using resistance spot welding machine with current 8kA, 9kA, 10kA, 11kA and 12kA. Tests performed include hardness testing, shear, SEM and metallography. The results showed that the optimum tensile strength is 5,68kN and optimum Vickers hardness is 237.34 VHN samples were obtained at a current of 11kA. Giving current 11kA above will cause a decrease in tensile strength and Vickers hardness. Hardness distribution of Vickers hardness shows that nugget area has a higher hardness than the base metal. Microstructure also shows that the area to the nugget, grain growing and increasing bainite phase., Bake Hardening material is a material that is easily deformed before being given a heat treatment and become a hard deformed after being heat-treated. This material is a new material used in the automotive industry for car frame and car body. This material will be welded using Resistance Spot Welding machine. Resistance Spot Welding is one type of welding that is widely used in the automotive industry. This study aims to determine the effect of the current welding parameters of resistance spot welding to bake hardening material. The joining of bake hardening material is performed using resistance spot welding machine with current 8kA, 9kA, 10kA, 11kA and 12kA. Tests performed include hardness testing, shear, SEM and metallography. The results showed that the optimum tensile strength is 5,68kN and optimum Vickers hardness is 237.34 VHN samples were obtained at a current of 11kA. Giving current 11kA above will cause a decrease in tensile strength and Vickers hardness. Hardness distribution of Vickers hardness shows that nugget area has a higher hardness than the base metal. Microstructure also shows that the area to the nugget, grain growing and increasing bainite phase.]"

"This book covers a variety of topics in mechanics, with a special emphasis to fluid mechanics and energy transfer. Chapters are based on selected contributions presented during the Algerian Congress of Mechanics (CAM 2017), held on November 26 - 30, 2017, in Constantine, Algeria. The book covers theoretical analysis, modeling, and numerical treatment of performance-related problems of new refrigeration systems, heating and cooling. It reports on experimental research to solve problems related to the flow of microfluids, and relevant applications in the areas of chemical engineering, biochemistry, biomedicine and renewable energy. Further topics include methods for maintenance of mechanical structures, strength, wear, fracture, damage and life of structures, and image processing solutions for the design and 3D manufacturing of mechanical parts. Improvement, control and regulation of urban road traffic are also discussed in this book, thus offering a comprehensive, practice-oriented reference guide for academics and professionals. "

"Kebutuhan energi semakin meningkat dengan bertambahanya populasi manusia pada saat ini. Salah satu konsumsi energi terbesar adalah pada bidang industri khususnya pada gedung-gedung. Phase Change Material (PCM) merupaka salah satu solusi terhadap permasalahan kebutuhan energi ini. Beeswax merupakan salah satu PCM dengan kapasitas kalor yang tinggi. Material ini akan diuji dan dianalisis pada penelitian ini. Tujuan dari penelitian ini adalah untuk mengetahui sifat-sifat termal dari komposit beeswax dan nanopartikel CuO. Titik leleh dan kapasitas termal dari nano-PCM akan dianalisis dengan metodologi DSC (Different Scanning Calorymeter). Titik leleh dari nano-PCM menurun sebesar 0.6,0.63,0.66,1.07,1.41oC untuk 0.05,0.1,0.15,0.2,0.25 wt % secara berurutan. Tidak ada reaksi kimia diantara beeswax dan nanopartikel CuO berdasarkan hasil dari tes FTIR. Penambahan nanopartikel CuO akan meningkatkan kemampuan perpindahan kalor dari komposit, akan tetapi menurunkan kapasitas kalor dari komposit tersebut. Berdasarkan hasil yang telah didapatkan, penambahan nanopartikel akan meningkatkan kecepatan penghantaran kalor dibandingkan dengan material dasar.The demand of energy is increased in recent days. Experimental and implementation of phase change material as thermal storage is gained greater attention as solution to energy issue. Beeswax as one of phase change material with high thermal capacity is investigated in this paper. The objective of this paper is to analyze thermal properties and behaviors of beeswax-CuO Nano-PCM. The melting temperature and thermal capacity of nano-PCMs were determined by differential scanning calorimetry test. The melting temperature of nano-PCM decreased by 0.6,0.63,0.66,1.07,1.41oC for 0.05,0.1,0.15,0.2,0.25 wt %,respectively. There was no chemical reaction between CuO and beeswax based on FTIR test. Existing of CuO nanoparticles enhanced thermal conductivity of beeswax. Addition of CuO nanoparticles reduced heat capacity of beeswax. However, the change of latent heat would not cause significant effect towards the performance of beeswax-CuO. Thus, based on result, heat transfer of composite beeswax-CuO could be faster than base phase change material."

"Flowrate merupakan parameter penting dalam sebuah sistem refrijerasi. Selama ini, pengukuran flowrate dianggap hal yang menyulitkan lantaran membutuhkan ketersediaan alat ukur. Oleh karena itu, berbagai alternatif pengukuran mulai dilakukan untuk mengatasi hal tersebut. Diantaranya adalah pengukuran flowrate melalui putaran motor pada kompresor torak. Dimana putaran tersebut dapat dibaca melalui sinyal tekanan keluaran kompresor yang kemudian diolah secara matematis untuk mendapatkan frekuensi dari putaran motor. Dalam hal ini, ada dua metode matematis yang digunakan untuk membaca frekuensi dari tekanan keluaran kompresor, yaitu Fast Fourier Transform (FFT) dan Chirp-Z Transform (CZT) dimana beban pendinginan divariasikan guna melihat pengaruhnya terhadap nilai flowrate yang didapat.

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Flowrate is important value in a refrigeration system. During this time, flowrate measurement is considered difficult because it requires the availability of measuring instruments. Therefore, various alternative measurement begun to overcome it. Such as measuring flowrate based on the compressor speed in which it can be read by discharge pressure signal of the compressor and then it processed mathematically to obtain the frequency. In this case, there are two mathematical methods are used to find the frequency of the compressor speed, they are Fast Fourier Transform (FFT) and Chirp-Z Transform (CZT), where the cooling load was varied to see its effect on the flowrate that would be obtained."

"Flowrate merupakan parameter penting dalam sebuah sistem refrijerasi. Selama ini, pengukuran flowrate dianggap hal yang menyulitkan lantaran membutuhkan ketersediaan alat ukur. Oleh karena itu, berbagai alternatif pengukuran mulai dilakukan untuk mengatasi hal tersebut. Diantaranya adalah pengukuran flowrate melalui putaran motor pada kompresor torak. Dimana putaran tersebut dapat dibaca melalui sinyal tekanan keluaran kompresor yang kemudian diolah secara matematis untuk mendapatkan frekuensi dari putaran motor. Dalam hal ini, ada dua metode matematis yang digunakan untuk membaca frekuensi dari tekanan keluaran kompresor, yaitu Fast Fourier Transform (FFT) dan Chirp-Z Transform (CZT) dimana charging refrigeran divariasikan guna melihat pengaruhnya terhadap nilai flowrate yang didapat.Flowrate is important value in a refrigeration system. During this time, flowrate measurement is considered difficult because it requires the availability of measuring instruments. Therefore, various alternative measurement begun to overcome it. Such as measuring flowrate based on the compressor speed in which it can be read by discharge pressure signal of the compressor and then it processed mathematically to obtain the frequency. In this case, there are two mathematical methods are used to find the frequency of the compressor speed, they are Fast Fourier Transform (FFT) and Chirp-Z Transform (CZT), where the refrigerant charging was varied to see its effect on the flowrate that would be obtained."