Studi Ketidakstabilan Porpoising Pada Floatplane Dalam Operasi Lepas Landas Di Perairan Tenang

Aliffrananda, M Hafiz Nurwahyu (2021) Studi Ketidakstabilan Porpoising Pada Floatplane Dalam Operasi Lepas Landas Di Perairan Tenang. Masters thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Floatplane merupakan jenis pesawat amfibi yang dapat lepas landas dan mendarat di permukaan air dan landasan pacu. Pesawat ini dilengkapi dengan float atau pontoon di bagian bawah atau sayap pesawat yang berfungsi memberikan gaya apung. Dalam operasi floatplane, fenomena penting yang sering terjadi dan harus dihindari pada saat operasi lepas landas adalah porpoising, karena dapat menyebabkan ketidakstabilan float secara memanjang sehingga berdampak pada keselamatan dan kenyamanan penumpang. Studi ini membahas mekanisme terjadinya porpoising serta faktor atau variabel yang dapat mempengaruhi terjadinya fenomena ini. Berdasarkan studi literatur, faktor-faktor yang paling dominan dalam mempengaruhi porpoising meliputi letak titik berat memanjang (LCG) dan sudut deadrise pada lambung float. Dalam pembuktiannya, akan dikembangkan model numerik berbasis computational fluid dynamics (CFD) untuk mensimulasikan mekanisme terjadinya porpoising. Hasil simulasi kemudian divalidasi dengan hasil pengujian model sejenis pada pengujian towing tank. Permodelan numerik yang sudah tervalidasi selanjutnya digunakan untuk menginvestigasi pengaruh letak LCG dan sudut deadrise terhadap terjadinya porpoising dalam lima variasi kecepatan. Dari hasil studi, didapatkan bahwa letak LCG sebesar 52.9% LOA dan sudut deadrise 20º memberikan performa terbaik dibanding konfigurasi lainnya. Studi ini diharapkan dapat memberikan referensi kepada perancang float terkait letak LCG dan sudut deadrise yang optimal untuk meminimalkan terjadinya porpoising.
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Floatplane is an amphibious aircraft that is able to take off and land on the surface of water and runway. This aircraft is equipped with floats or pontoons at the bottom of the aircraft that provide buoyancy. In floatplane operations, porpoising is an important phenomenon that often occurs and must be avoided during takeoff, as it causes longitudinal instability which causes disturbance on the safety and comfort of the passengers. This study discusses the mechanism of porpoising as well as factors or variables that influence the occurrence of this phenomenon. Based on literature studies, the dominant factors that influence the porpoising phenomenon include the location of the longitudinal center of gravity (LCG) and the deadrise angle. A numerical model based on computational fluid dynamics (CFD) is developed to simulate the mechanism of porpoising. The simulation results are then validated against the towing tank experiment results of a similar model. This validated numerical model is used to investigate the effects of LCG ordinates and deadrise angles on the occurrence of porpoising with five velocity variations. From the study, it is found that the LCG ordinate of 52.9% LOA and the deadrise angle of 20 degrees gave the best performance compared to other configuration. This study is expected to provide input reference to designers regarding the optimal location of the LCG and the optimal deadrise angle to minimize porpoising.

Item Type:	Thesis (Masters)
Uncontrolled Keywords:	CFD, Deadrise, Floatplane, LCG, Porpoising, Take-off, CFD, Deadrise, Floatplane, LCG, Lepas Landas, Porpoising.
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 V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering > VM311 Catamarans. V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering > VM751 Resistance and propulsion of ships V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering > VM761 Stability of ships
Divisions:	Faculty of Marine Technology (MARTECH) > Naval Architecture and Shipbuilding Engineering > 36101-(S2) Master Thesis
Depositing User:	M Hafiz Nurwahyu Aliffrananda
Date Deposited:	09 Mar 2021 03:48
Last Modified:	09 Mar 2021 03:49
URI:	http://repository.its.ac.id/id/eprint/83889

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