No abstract

This study aims to obtain the characteristics of the Savonius turbine based on the ratio of the inlet and outlet blades by using a modified blade shape and analyzing numerical simulations of the speed and pressure around the turbine blades. The use of Savonius turbines can be a solution because it produces large torque even if installed at low wind speed. Savonius blade modification into a double blade with a combination of type L and U aims to capture greater wind energy while generating greater electrical power. The study was tested at speeds of 3, 5, 7, and 9 m/s with variable differences in the side in and out of the turbine. However, what is presented in this article is the test parameters at a wind speed of 7 m/s. The test obtained data in the form of torque, generator speed, voltage, and current produced by the turbine. Once analyzed it can be concluded that the best performance is produced by a single blade rotor, then the rotor is 1:1, 2:1, and the lowest performance is obtained from the 3:1 rotor. The results of the study indicate that the Savonius turbine has optimum performance on a single blade rotor model at 189 rpm, the power coefficient value is 0.039, turbine power is 80.26 W, generator power is 3.08, and system efficiency is 3.84%.

<p align="center"><strong>Abstrak</strong></p><p><em>Roda gigi</em><em> adalah bagian dari </em><a title="Mesin" href="https://id.wikipedia.org/wiki/Mesin"><em>mesin</em></a><em> yang berputar dan berguna untuk men</em><a title="Transmisi" href="https://id.wikipedia.org/wiki/Transmisi"><em>transmisikan</em></a><em> daya</em><em>. Pembuatan roda gigi pada umumnya dibuat dengan proses pemesinan. Tujuan penelitian ini membuat roda gigi dengan proses metalurgi serbuk. Metalurgi serbuk adalah proses penekanan terhadap serbuk agar serbuk dapat menempel satu dengan lainnya sebelum ditingkatkan ikatannya dengan proses sintering. Proses ini dilakukan dengan  menggunakan bahan baku dari serbuk tembaga dan aluminium sebagai bahan bakunya. Proses kompaksi menggunakan  mesin cetak hidrolik yang berkemampuan tekan 6 ton, hasil cetak  roda gigi yang dilakukan dari  bahan serbuk tembaga, selanjutnya dilakukan proses sintering dengan temperatur  868⁰C dan waktu penahanan 1 jam sebelum dilakukan uji kekerasan.</em> <em>Pengujian kekerasan dilakukan dengan metode Brinell dengan beban 6,25 (kg) dan diameter indentor sebesar 2,5 (mm) dengan menggunakan mesin uji kekerasan GNEHM HORGEN beserta perlengkapannya.</em> <em>Hasil pembuatan  roda gigi terbaik menggunakan komposisi bahan tembaga 100%, sedangkan produk paduan terbaik dengan komposisi bahan tembaga 75% dan 25% aluminium.</em></p><p> </p><p><strong>Kata kunci</strong> : <em>Roda Gigi, Metalurgi Serbuk, Sintering, Mesin Cetak Hidrolik</em></p>

No abstract

The squeezing process of grated coconut into coconut milk, and the following process of making the milk into coconut oil, which is done by people living in rural areas, is until now still very traditional. They do it manually (by hands) so that they produce 7.2 kg/hour grated coconut or 3.6 litres/hour thick coconut milk.To effectify the process, the squeezing needs to be mechanized, using a grated coconut squeezer machine.The machine is designed on the basis of Screw Press system with a ¼ HP 1450 rpm electric motor power using a pulley belt transmission and a gear box. The squeezer's force refers to coconuts aging between 341 and 413 days (hand squeezing force normally practised by coconut oil producers in rural areas).This prototype of machine has the capacity of producing 53.2 kg/hour grated coconut or 26.6 litres/hour thick coconut milk, which has similar quality (in colour, smell and texture) as that manually squeezed.