Analisa Thrust dan Torsi pada Propeller C4-40 dengan Penambahan Kort Nozzle Terhadap Variasi Pitch

Pada saat ini ada berbagai macam jenis propeller, salah satunya propeller CPP (Controllable pitch propeller). Propeller CPP dapat mengubah sudut pitch, dan pada pitch-pitch tertentu dapat menarik mundur kapal tanpa harus mengubah putaran. Namun yang perlu diingat bahwa CPP hanya memiliki satu desain pitch dimana mengubah posisi pitch berarti mengurangi efisiensi baling-baling. Sehingga dibutuhkan kort nozzle untuk meningkatkan efisiensi. Penambahan kort nozzle merupakan salah satu pengembangan Energy Saving Device (ESD) dimana selain meningkatkan efisiensi juga mampu meningkatkan nilai thrust. Rumusan masalah pada penelitian ini yaitu ingin mengetahui perubahan thrust, torsi dan efisiensi pada propeller CPP C4-40 setelah penambahan kort nozzle 37. Penelitian ini diawali dengan penentuan dimensi propeller, serta jenis dan dimensi nozzle. Kemudian dilakukan perancangan dan penggambaran propeller C4-40 dengan kort nozzle 37 terhadap perubahan pitch 0°, 22,5° dan 45°. Langkah selanjutnya adalah dilakukan proses meshing dimana tiap pitch jumlah meshingnya berkisar antara 2,3- 3,5 juta cell. Langkah terakhir adalah melakukan simulasi performa propeller dengan nozzle menggunakan software berbasis Computational Fluid Dynamic. Dari penelitian ini, dapat disimpulkan bahwa penambahan kort nozzle 37 pada propeller C4-40 mengubah nilai thrust, torsi dan efisiensi yang cukup signifikan. Thrust hanya mengalami kenaikan pada pitch 0° J 1,4 dan pitch 22,5°. Kenaikan thrust terbesar pada pitch 22,5° J 0,6 yaitu 88,74%. Torsi mengalami penurunan kecuali pada pitch 0° J 0,8-1,4. Penurunan torsi terbesar pada pitch 45° J 1,2 yaitu 83%. Sedangkan efisiensi mengalami penurunan di semua sudut pitch. Dimana penurunan terbesar pada pitch 45° J 1 sebesar 99,83%. ===================================================================================================== At this time there are various types of propellers, one of which is the CPP propeller (Controllable pitch propeller). The CPP propeller can change pitch angles, and at certain pitches it can pull the ship backwards without having to change the rotation. But keep in mind that the CPP has only one pitch design where changing the pitch position means reducing the efficiency of the propeller. So it takes a kort nozzle to increase efficiency. The addition of a kort nozzle is one of the developments of an Energy Saving Device (ESD) which in addition to increasing efficiency it is also able to increase the thrust. Problem formulation of this research is to find out changes in thrust, torque and efficiency on the propeller CPP C4-40 after the addition of kort nozzle 37. This research begins with determining the dimensions of the propeller, also the types and dimensions of the nozzle. Then the design and drawing of the propeller C4-40 with a kort nozzle 37 was carried out for pitch changes of 0°, 22.5° and 45°. The next step is a meshing process where each pitch the number of meshing ranges from 2.3 to 3.5 million cells. The last step is to simulate the performance of the propeller with the nozzle using software based on Computational Fluid Dynamic. From this research, it can be concluded that the addition of kort nozzle 37 on the propeller C4-40 changes the thrust, torque and efficiency values significantly. Thrust only increased at pitch 0° J 1.4 and pitch 22.5°. The greatest increase in thrust at pitch 22.5° J 0.6 is 88.74%. Torque is reduced except for pitch 0° J 0.8-1.4. The biggest decrease in torque at pitch 45° J 1.2 is 83%. Meanwhile efficiency has decreased at all pitch angles. Where the biggest decrease in pitch 45° J 1 is 99.83%