Ardhiansyah, Fahmy (2024) Studi Eksperimen dan Numerik Interaksi Dua Bangunan Apung dengan Konfigurasi Bersebelahan (Side-by-Side). Doctoral thesis, Institut Teknologi Sepuluh Nopember Surabaya.
![[thumbnail of 7018201003-Dissertation.pdf]](http://repository.its.ac.id/style/images/fileicons/text.png) |
Text
7018201003-Dissertation.pdf - Accepted Version Restricted to Repository staff only until 1 October 2026. Download (5MB) | Request a copy |
Abstract
Disertasi ini membahas tema mengenai pentingnya mengetahui karakteristik dua bangunan apung berbentuk kapal konfigurasi bersebelahan, dimana konfigurasi tersebut sering ditemui pada aktifitas kegiatan alih muat antar kapal di lautan dan dua kapal yang saling berpapasan dalam lintasan alur pelayaran. Kegiatan ini dinilai memiliki resiko tinggi terutama pada kegiatan pemuatan barang berbahaya seperti minyak atau gas. Permasalahan yang ditinjau adalah mengenai bagaimana interaksi hidrodinamik yaitu karakter pola gelombang dan perilaku gerak yang timbul pada variasi jarak variasi jarak celah d terhadap parameter lebar model kapal B, dengan nilai d =2B, d = B; d=1B, d=2/3B, d=1/2B, d=1/3B. Untuk mengatahui karakter tersebut dilakukan dengan pendekatan eksperimen dan numerik, perbedaan hasil dari masing-masing metode juga akan ditinjau untuk mengetahui apa parameter yang berperan penting. Metode eksperimen, numerik fluida viskos, dan numerik fluida ideal digunakan model dengan geometri model skala 1:80. Tinjauan hanya dilakukan akibat pengaruh gelombang dengan arah datang dari depan, sementara pengaruh arus dan angin diabaikan. Metode eksperimen dilakukan di laboratorium kolam pengujian gelombang wave flume tank dengan menempatkan model uji yang dikenai gelombang reguler, variasi nilai panjang gelombang terhadap panjang model L pada rentang /L = 0.6 - /L= 2.03. Simulasi numerik fluida ideal diselesaikan dengan bantuan perangkat lunak ANSYS AQWA yang menerapkan teori aliran potensial. Selanjutnya penyelesaian numerik fluida viskos dengan bantuan CFD code STAR CCM+ yang menerapkan teori Unsteady Reynolds Averaged Navier Stokes (URANS). Overset mesh dipilih sebagai teknik mesh yang dianggap optimal dengan model turbulen k-Langkah waktu t = 0.001 detik ditentukan dengan mempertimbangan bilangan Courant-Friedrichs-Lewy CFL < 0.75. Hal ini berkaitan dengan gelombang reguler yang dibangkitkan dari kondisi batas model dan volume of fluid (VOF) yang mendefinisikan interaksi antara air dan udara. Dari hasil eksperimen didapatkan pola gelombang pada variasi konfigurasi jarak memberikan gambaran bahwa terjadi resonansi gelombang di celah kedua model. Amplifikasi tinggi gelombang hingga sebesar = 3.50 terjadi pada gelombang pendek dengan nilai kira-kira /L = 0.6. Secara umum amplifikasi gelombang terjadi saat /L = 0.6 - /L = 0.8 dan /L = >1.5 untuk semua variasi konfigurasi. Kemudian hasil simulasi numerik fluida viskos menunjukkan adanya pengaruh variasi jarak celah, dimana pada nilai /L = 2.03 meghasilkan gerak roll dengan nilai hingga 2 pada d=1/2B, d=B, dan d=2B. Sedangkan untuk gerak heave dan pitch hanya memberikan pengaruh sangat sedikit. Saat dibandingkan tiga metode yang digunakan memberikan hasil yang bebeda pada gerak roll, dimana terjadi pada metode eksperimen 4 = 1 dan numerik viskos 4 = 2 namun tidak memberikan fenomena gerak roll pada metode numerik fluida ideal 4 = 0.
====================================================================================================================================
This dissertation discusses the theme of the importance of knowing the characteristics of two floating structures in the form of ships in adjacent configurations, where these configurations are often found in the activities of transferring loading between ships at sea and two ships passing each other in the shipping lane. This activity is considered to have a high risk, especially in the loading of dangerous goods such as oil or gas. The problem reviewed is about how the hydrodynamic interaction is the character of the wave pattern and motion behaviour that arises in the variation of the gap distance variation d against the width parameter of the ship model B, with the value of d = 2B, d = B; d = 1B, d = 2/3B, d = 1/2B, d = 1/3B. Experimental and numerical approaches are used to investigate these characteristics, and the difference in results from each method will also be reviewed to determine which parameters play an important role. Experimental, viscous fluid numerical, and ideal fluid numerical methods were used with a 1:80 scale model geometry. The review is only conducted due to the influence of waves with the direction of arrival from the front, while the influence of current and wind is ignored. The experimental method was carried out in a laboratory wave flume tank testing pond by placing the test model subjected to regular waves, varying the wavelength value against the model length L in the range /L = 0.6 - /L = 2.03. The numerical simulation of ideal fluid was completed with the help of ANSYS AQWA software that applies potential flow theory. Furthermore, the numerical solving of viscous fluid with the help of CFD code STAR CCM+ which applies the Unsteady Reynolds Averaged Navier Stokes (URANS) theory. Overset mesh was chosen as the optimal mesh technique with turbulent model k-Langkah time t = 0.001 s was determined by considering Courant-Friedrichs-Lewy number CFL < 0.75. This relates to the regular waves generated from the model boundary conditions and the volume of fluid (VOF) that defines the interaction between water and air. From the experimental results, it is found that the wave pattern in the variation of the distance configuration illustrates that there is wave resonance in the gap between the two models. Amplification of wave height up to the amount = 3.50 occurs in short waves with a value of approximately /L = 0.6. In general, wave amplification occurs when /L = 0.6 - /L = 0.8 and /L = >1.5 for all configuration variations. Then the results of numerical simulations of viscous fluid show the effect of variations in the gap distance, where at the value of /L = 2.03 it produces roll motion with values up to 2 at d = 1/2B, d = B, and d = 2B. While for heave and pitch motion only gives very little effect. When compared the three methods used give different results on roll motion, which occurs in the experimental method 4 = 1 and viscous numerical 4 = 2 but does not give the phenomenon of roll motion in the numerical method of ideal fluid 4 = 0.
| Item Type: | Thesis (Doctoral) |
|---|---|
| Uncontrolled Keywords: | Interaksi Hidrodinamik; Studi Eksperimen; CFD, Konfigurasi Bangunan Apung Bersebelahan |
| Subjects: | V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering > VM156 Naval architecture V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering > VM161 Ships--Hydrodynamics |
| Divisions: | Faculty of Marine Technology (MARTECH) > Ocean Engineering > 38001-(S3) PhD Thesis |
| Depositing User: | Fahmy Ardhiansyah |
| Date Deposited: | 28 Oct 2024 02:51 |
| Last Modified: | 28 Oct 2024 02:51 |
| URI: | http://repository.its.ac.id/id/eprint/115766 |
Actions (login required)
 |
View Item |