Control of flow structure on low swept delta wing using unsteady leading edge blowing

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Makina Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2016

Öğrenci: CENK ÇETİN

Danışman: MEHMET METİN YAVUZ

Özet:

There is an increasing interest in recent years in the aerodynamics of low swept delta wings, which can be originated from simplified planforms of Unmanned Air Vehicles (UAV), Unmanned Combat Air Vehicles (UCAV) and Micro Air Vehicles (MAV). In order to determine and to extend the operational boundaries of these vehicles with particular interest in delaying stall, complex flow structure of low swept wings and its control needs to be understood. Among different flow control strategies, blowing through different locations of the wing has been commonly used due to its high effectiveness. Steady and unsteady blowing with different configurations in terms of excitation pattern at different injection rates needs to be studied thoroughly. In the current study, it is aimed to control the flow structure of a low swept delta wing with sweep angle of Λ=45o using unsteady blowing through leading edges. Experiments are conducted in low speed wind tunnel. First, the unsteady blowing test set-up, which is able to provide a broad range of periodic excitation frequencies and injection rates, is built and characterized using Hot Wire Anemometry. Then, the flow structure on the wing is quantified using surface pressure measurements and Particle Image Velocimetry (PIV) technique for the attack angles varying from 7 to 20 degrees at Reynolds number of Re=35000. Different periodic excitation frequencies, varying from 2 Hz to 24 Hz, at fix momentum coefficient are tested and compared with the steady injection cases. The results indicate that unsteady blowing through leading edges of the planform is quite effective for the eradication of stall.