Minat dalam pembinaan pesawat ‘High Altitude Long Endurance’ (HALE) meningkat dengan pesat pada masa kini kerana manfaatnya yang berpotensi untuk penggunaan tentera dan komersil. Walau bagaimanapun, flutter merupakan masalah aeroelasticity yang biasa kerana pesawat jenis ini mempunyai sayap yang panjang, nipis dan bernisbah tinggi. Oleh itu, adalah berguna untuk membangunkan pesawat subskala dengan keupayaan ujian ‘flutter’ untuk menyiasat kesan daya aerodinamik, inersia dan elastik yang bertindak pada sayap fleksibel. Dalam projek ini, satu platform yang murah direka dan dibangunkan. Reka bentuk yang dibuat mesti mencapai matlamat projek ini. Oleh itu, prestasi penerbangannya dari segi aerodinamik, kestabilan dan kawalan, jumlah berat dan instrumen dicapai dengan menggunakan XFLR5, Excel, Arduino dan SolidWorks. Seterusnya, pesawat itu dibuat dengan busa Expanded PolyProplyene (EPP) dan Depron Extruded Polystyrene (XPS) mengikut reka bentuk. Kemudian, 6 ujian penerbangan dilakukan, dan ia berjaya berlepas dalam 3 penerbangan. Penambahbaikan telah dibuat supaya ‘flutter’ berlaku. Walaubagaimanapun, ‘flutter’ tidak berlaku kerana kekakuan sayap susah diubah dengan tepat. Disebabkan kemalangan berlaku, ujian penerbangan telah dihentikan dan diganti dengan Ujian Gegaran Tanah (GVT). Dari GVT, kekerapan lenturan dan ‘pitching’ sayap asal dan sayap diubahsuai adalah 3.745 Hz, 84.28 Hz, 6.193 Hz dan 118.1 Hz masing-masing. Kekerapan lenturan bagi ekor mendatar dan menegak adalah 8.324 Hz dan 7.643 Hz masing-masing.
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The interest in building High Altitude Long Endurance (HALE) aircraft are increasing rapidly recently due to its potential benefits on military and commercial usage. However, flutter is always an aeroelasticity issue as these aircraft usually has long, thin and high aspect ratio wing. Thus, it is helpful to develop a subscale aircraft with flutter test capability to investigate the effect of aerodynamic, inertia and elastic forces that act on the flexible wing. In this project, a low-cost, university-level platform is designed and developed. The design was being made to achieve the objectives of this project. Thus, its flight performance in terms of aerodynamics, stability and control, total weight and instrumentations were achieved by using XFLR5, Excel, Arduino and SolidWorks. Next, the aircraft was fabricated with Expanded PolyProplyene (EPP) foam and Depron Extruded Polystyrene (XPS) foam according to the design. Then, a total of 6 flight tests were done, and it took off successfully 3 times. Improvements were being made to initiate flutter. However, flutter was failed to be initiated as the stiffness of the wing is difficult to be tailored. Due to some accidents, the flight test was being put to a stop and Ground Vibration Test (GVT) was being carried out instead. From the GVT, the natural bending and pitching frequencies of the original wing and modified wing are 3.745 Hz, 84.28 Hz, 6.193 Hz and 118.1 Hz respectively. For the empennage’s horizontal and vertical stabiliser, the natural bending frequencies are 8.324 Hz and 7.643 Hz respectively.
Development of a subscale aircraft for flutter test platform / Tan Chun Khuen