Riman Sipahutar
Lecturer of Magister Program Mechanical Engineering, Sriwijaya University

Published : 6 Documents
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THE EFFECT OF STEERING BLADE ANGLES OF HELICAL TURBINE FOR POWER GENERATION IN IRIGATION DAM OF Sipahutar, Riman; Niharman, Niharman
Journal of Mechanical Science and Engineering Vol 2, No 1 (2015): Journal of Mechanical Science and Engineering
Publisher : Sriwijaya University

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Abstract

The Gorlov vertical axis water turbine is suitable to harness the water flow in the creation of kinetic energy for the irigation dam. The turbine tested in this study was ther Gorlov helical turbine blade with steering angles of 00, 300, 450 and 600 turbine diameter (d) of 0.30 m, height (h) of 0.50 m and the NACA 0020 profile. The testing was conducted on the irigation dam of Seluma Bengkulu. The water flow showed in the velocity (Uair) of  0.85 m / s and a round (n) of 110 rpm. The results were achieved by setting the blades in steering torque coefficient (Ct) of 0.309 are turbine efficiency (ηt) of 28.5% and a power turbine (Pt) of 13.699 Watts.
ANALISYS OF EFFECT OF OUTSIDE AIR SPEED TO AIR HUMIDITY AND REFRIGERATOR COEFFICIENT OF PERFORMANCE Sipahutar, Riman; Irawan, Ferry
Journal of Mechanical Science and Engineering Vol 3, No 1 (2016): Journal of Mechanical Science and Engineering
Publisher : Sriwijaya University

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Abstract

Air conditioning is essential for most humans and are associated with human thermal comfort. At conditioned room where the condition can occur outside air (atmosphere) into the room. Althouht the author was interested in researching this influx of outside air. The aims of this research would be able to examine the effect of the entry of outside air to the room air humidity and refrigerator coefficient of performance. The method used is to perform laboratory-scale experiment with conditioned room with air conditioning or no air conditioning which then incorporate outside air into the room. From this experiment would get experimental result, the result of theoretical calculation, and the result of calculation by using the simulator program. By entering the outside air was obtained that the outside air increases the humidity in the room and affect refrigerator coefficient of performance. The experimental results showed that the average maximum condition occurs at a speed of 1 m/s and at 20 minutes. It can be concluded that the outside air entering the room using the air conditioner would improve indoor air humidity and increase the cooling load means affect refrigerator coefficient of performance. And in a room without air conditioner caused indoor air humidity getting closer to the comfort zone.
ANALYSIS OF A COMPARED TEMPERATURE USING CAPILLARY TUBE DIFFERENT MEASUREMENT LENGTH AT ROOM 3 X 4 M2 HELPING AC PORTABLE Wiseta, Rendy; Sipahutar, Riman; Faizal, Muhammad
Journal of Mechanical Science and Engineering Vol 2, No 2 (2015): Journal of Mechanical Science and Engineering
Publisher : Sriwijaya University

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Abstract

At this time along with the times a lot of problems that occur in this world like the Earth's warming temperatures globally . Human needs of the air conditioning apparatus has become a staple in our daily lives . There is also a saying that the Air Conditioner ( AC ) has become a mandatory item installed in homes without air conditioning because of the environment around the home became more sultry and hot when we were in the neighborhood . In developments at this time have many types of AC marketed like Split AC , AC Windows , Central air conditioning and so on . A capillary tube expansion device or lowering pressure so cheap that researchers sought to examine the ratio of capillary -sized 33 , 54 , and 76 cm to the temperature of an air conditioner Portable. Results comparative study of the capillary tube length obtained the lowest total heat value is 9086 , 6925 Btu / Hr and the highest is 15144.4875 Btu / Hr .
Study of Bio-Coal Briquette as Solid Fuel for Aluminum Smelter Pratiwi, Diah K.; Sipahutar, Riman; Arifin, Amir
Sriwijaya Journal of Environment Vol 2, No 3 (2017): Low Land
Publisher : Program Pascasarjana Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22135/sje.2017.2.3.99-101

Abstract

Research on alternative energy today based on issues of global warming and greenhouse effects. The use of coal briquettes from low-calorie coal derived from mines in the province of South Sumatera originally destined for the food industry is less desirable because it emits black and smelly smoke, is difficult to turn on, and it is difficult to shut down quickly. So the thought arises to use this coal briquettes for the manufacturing industry and metal casting. In a previous study, the manufacture of mixed briquettes between low calorie coal (lignite) and biomass was more environmentally friendly due to low sulfur content. Therefore, in this study, a study was conducted to find the best biomass species to be mixed with lignite to bio-coal with the highest carbon content criteria and lowest sulfur content. The results showed that the mixture type between coconut shell and lignite reached the optimum condition with carbon content of 57.923% and the lowest sulfur was 0.259% in the mixture ratio of 9 : 1. The combustion temperature reaches 1500 K at furnace efficiency of 48%.Keywords: bio-coal briquettes; lignite. coconut shell; enthalpy difference; carbon and sulfur content; flame temperature;
PENGARUH PENCAMPURAN METANOL PADA BAHAN BAKAR PERTAMAX TERHADAP ANGKA OKTAN, NILAI KALORI, DAN KONSUMSI BAHAN BAKAR Sipahutar, Riman; Madona, Leonardo
Jurnal Rekayasa Mesin Vol 15, No 3 (2015): Journal of Mechanical Engineering
Publisher : Sriwijaya University

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Abstract

Setiap mesin kendaraan memerlukan bahan bakar agar mesin kendaraan tersebut dapat beroperasi. Setiap mesin kendaran membutuhkan bahan bakar yang berbeda sesuai dengan spesifikasi dari mesin tersebut. Dalam pengujian ini penulis menggunakan mesin sepeda motor 4 langkah dengan rasio kompresi 10.6 : 1 yang mana sesuai dengan tabel perbandingan kompresi dan angka oktan, mesin berasio kompresi 10.6 : 1 membutuhkan bahan bakar dengan angka oktan diatas 100 RON. Oleh karena itu penulis ingin mengetahui bahan bakar yang sesuai dengan rasio kompresi mesin sepeda motor tersebut. Penulis melakukan percobaan dengan mencampurkan metanol kadar 100 % pada bahan bakar pertamax guna meningkatkan angka oktan bahan bakar pertamax. Kemudian penulis juga menghitung nilai kalori dari pencampuran tersebut dan juga melakukan uji konsumsi bahan bakar dengan menggunakan sepeda motor tersebut. Adapun variasi pencampuran yang dilakukan adalah kadar M0 ( 100% Pertamax ), M10 ( 90 % Pertamax + 10% Metanol), M20 ( 80% Pertamax + 20% Metanol ), M 30 ( 70 % Pertamax + 30% Metanol ), M40 ( 60% Pertamax + 40% Metanol), dan M50 (50 % pertamax + 50 % metanol). Dari hasil pengujian didapat bahwa campuran yang cocok untuk digunakan pada mesin kendaraan sepeda motor ini adalah campuran M20karena lebih hemat bahan bakar dan meningkatkan performa mesin. Angka oktan tertinggi terdapat pada campuran M50 dan angka oktan yang cocok untuk mesin kendaraan yang digunakan adalah angka oktan pada campuran M20yaitu sebesar 107,3 RON. Nilai kalori terendah terdapat pada variasi campuran M50 dan pada pengujian ini konsumsi bahan bakar paling sedikit terdapat pada saat menggunakan campuran M20 dimana volume yang tersisa yaitu 54 ml dari volume awal 100 ml.
PENGARUH VARIASI SUHU DAN WAKTU KONVERSI BIODIESEL DARI MINYAK JARAK TERHADAP KUANTITAS BIODIESEL YANG DIHASILKAN Sipahutar, Riman; Lumban Tobing, Harry Lukman
Jurnal Rekayasa Mesin Vol 13, No 1 (2013): Journal of Mechanical Engineering
Publisher : Sriwijaya University

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Abstract

ABSTRAK Biodiesel merupakan bahan bahar substitusi solar dewasa ini. Salah satu minyak nabati yang memiliki banyak keunggulan untuk dikonversi menjadi biodiesel adalah minyak jarak pagar. Proses produksi biodiesel dari minyak jarak dipengaruhi beberapa faktor diantaranya konsentrasi metanol, konsentrasi katalis, pengaruh suhu, dan pengaruh waktu reaksi. Penelitian ini dilakukan untuk mengetahui pengaruh suhu dan waktu reaksi dalam reaktor biodiesel. Penelitian menggunakan metode rancangan acak dengan variasi suhu 300C, 450C, 600C dan variasi waktu 30 menit, 60 menit, 90 menit, 120 menit. Hasil penelitian menunjukkan  variasi suhu memberikan pengaruh berbeda sangat nyata terhadap kuantitas biodiesel sedangkan variasi waktu memberikan pengaruh berbeda tidak nyata terhadap kuantitas biodiesel yang dihasilkan. Suhu terbaik  pada penelitian adalah 60 0C dan waktu terbaik selama 120 menit. Kata kunci: Biodiesel, Minyak Jatropha, Suhu, Panas, Reaktor. ABSTRACT Biodiesel is a substitute fuel of diesel fuel nowadays. One of plant oils that has many advantage converted to biodiesel is Jatropha Oil. The process of biodiesel production from Jatropha Oil was affected by several factors including consentrate of methanol, consentrate of catalyst, temperature effect, and time reaction effect. This research was conducted to determine the effect of temperature and time reaction in biodiesel reactor. The research using method of randomized design with  variation temperature 300C, 450C, 600C and variation time 30 minutes, 60 minutes, 90 minutes, 120 minutes. The result showed that variation temperature give very real different effect on the quantity of biodiesel while variation time give not much real different effect on the quantity of biodiesel produced. The best temperature in research was 600C and best time was 120 minutes. Keywords : Biodiesel, Jatropha Oil, Temperature, Heat, Reactor.