Studi Computational Fluid Dynamics (CFD) Asymmetric Un-Circular Pre-Duct dalam Meningkatkan Kinerja Penggerak Kapal

Munazid, Ali (2025) Studi Computational Fluid Dynamics (CFD) Asymmetric Un-Circular Pre-Duct dalam Meningkatkan Kinerja Penggerak Kapal. Doctoral thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Upaya efisiensi dengan peningkatan propulsive efficiency dan menurunkan hambatan adalah teknologi Energy Saving Device (ESD) diantaranya pre-duct yang lebih murah, non-invasive dan mudah serta menghasilkan efisiensi dengan interaksi positif antara hull dan propeller, efek equalizing, memperbaiki distribusi beban propeller untuk mengurangi kerugian hub vortex propeller serta meningkatkan kinerja kavitasi propeller. Pre-duct banyak diterapkan pada kapal tipe displasemen dengan koefisien block yang besar, karena memiliki sparation vortex yang relatif kuat, dengan melihat daerah bilge buritan, memungkinkan dan memberikan ruang perbaikan propulsive menggunakan pre-duct dalam memperbaiki axial flow losses dengan menghomogenisasikan aliran. Beberapa pengembangan asymmetris di buritan kapal antara lain: bentuk linggi ansymmetris, stern-bulb ansymmetris, strut/swirl ansymmetris dilaporkan mengefisiensikan energy. Dengan menggunakan perangkat lunak komersial Ansys-CFX dilakukan simulasi propeller open water test serta self-propeller test untuk mendapatkan kinerja dari propeller tanpa pre-duct serta propeller yang menggunakan pre-duct dengan bentuk circular, uncircular dan asymmetris uncircular. Dari hasil permodelan didapatkan bahwa keberadaan pre-duct pada badan kapal memberikan hambatan tambahan akan tetapi besarnya tidak sebesarnya besarnya penurunan hambatan badan kapal sehingga hambatan total menurun, selain itu meningkatkan daya dorong kapal, sehingga efisiensi propulsive meningkat disebebkan pre-duct mengontrol aliran terpisah dengan meluruskan aliran ke arah aksial, bentuk pre-duct dengan efisiensi propulsive yang tinggi adalah asymmetric uncircular-1 sebesar 0.797
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Effort to improve efficiency by by increasing propulsive efficiency and reducing drag are Energy Saving Device (ESD) technologies, including cheaper, non-invasive, and easy pre-ducts, which produce efficiency with positive interactions between the hull and propeller, equalizing effects, improving propeller load distribution to reduce propeller hub vortex losses, and improving propeller cavitation performance. Pre-ducts are widely applied to displacement-type ships with large block coefficients because they have relatively strong vortex separation. By looking at the stern bilge area, it allows and provides space for propulsive improvements using pre-ducts to improve axial flow losses by homogenizing the flow. Several asymmetric developments at the stern of the ship include: asymmetric high-rise shapes, asymmetric stern-bulbs, asymmetric struts/swirls, which are reported to be energy efficient. Using commercial software Ansys-CFX, open water propeller test simulations and self-propeller tests were carried out to obtain the performance of propellers without pre-ducts and propellers using pre-ducts with circular, uncircular, and asymmetric uncircular shapes. From the modeling results, it was found that the presence of pre-duct on the ship's hull provides additional resistance, but the magnitude is not as large as the reduction in ship's hull resistance so that the total resistance decreases, in addition to increasing the ship's thrust, so that propulsive efficiency increases because the pre-duct controls the separate flow by straightening the flow in the axial direction, the form of the pre-duct with high propulsive efficiency is asymmetric uncircular-1 of 0.797.

Item Type:	Thesis (Doctoral)
Uncontrolled Keywords:	ESD, Pre-Duct, Uncircular Duct, Asymmetric Duct
Subjects:	V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering > VM163 Hulls (Naval architecture) V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering > VM753 Propellers V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering > VM773 Ship propulsion, Electric
Divisions:	Faculty of Marine Technology (MARTECH) > Marine Engineering > 36001-(S3) PhD Theses
Depositing User:	Ali Munazid
Date Deposited:	14 Aug 2025 03:00
Last Modified:	14 Aug 2025 03:00
URI:	http://repository.its.ac.id/id/eprint/128013

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