Akademik Veri Yönetim Sistemi
Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Makina Mühendisliği Bölümü, Türkiye
Tezin Onay Tarihi: 2018
Tezin Dili: İngilizce
Öğrenci: Recep Hilmi Kanlıoğlu
Danışman: MEHMET ÇALIŞKAN
Özet:Prediction of interior noise level within a helicopter fuselage is an important design aspect considering competition in the aviation global market combined with customer's comfort expectations. Especially, in the development phase of a new product, accurate vibro-acoustic models are required to give an engineering assessment to guide the design. The objective of this study is to review noise-generating mechanism on helicopters and vibro-acoustic analysis techniques, and to build two different predictive Statistical Energy Anal-ysis (SEA) models for a conventional type of helicopter. One approach involves SEA where structures are modelled by SEA subsystems, while the other approach is hybrid FEM-SEA where stiffer components having few modes at the low-to-mid frequency range are constructed with finite element while the rest represented by SEA subsystems. Excita-tions due to the main gearbox is taken from flight measurements on similar helicopters. Turbulent Boundary Layer (TBL), engine airborne noise and main and tail rotor excitations are also applied as main sources of interior noise. Through the analysis, sound pressure levels for the cruise condition are evaluated in the frequency range of interest up to 16000 Hz by commercial software.