Roll characteristics and shape optimization of the free-to-rotate tail-fins on a canard-controlled missile

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Havacılık ve Uzay Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2014

Öğrenci: ERHAN FEYZİOĞLU

Danışman: İSMAİL HAKKI TUNCER

Özet:

In this thesis, a numerical investigation of roll motion characteristics and planform optimization of free-to-rotate tail fins are performed. Steady and unsteady, asymmetric flows due to the aileron deflection in canard fins are computed by solving the Reynolds-Averaged Navier-Stokes (RANS) solutions with FLUENT. Instantaneous unsteady aerodynamic loads and the moment of inertia of the tail fins are used to evaluate the angular displacement of the tail fins. The rotary grid motion is then implemented by a User-Defined-Function (UDF) developed. The unsteady solution provides the roll motion history and the final steady roll rate of the free-to-rotate tail fins. The numerical methodology is first validated on two test cases for which the experimental data are available. A gradient based planform optimization is then performed on the free-to-rate tail fins in order to minimize the roll rate while not allowing any reduction in the total normal force. The gradient vector of the objective function and the line search along the gradient vector are performed by discrete evaluations. The optimum tail fin planform reduces the roll rate of the tail fins by about 6% and increases the normal force by about 4%.