The dorsal S-duct inlet of a HALE blended wing body UAV faces complex unsteady disturbances during operation. This study numerically investigates its aerodynamic response to gust excitations. Using CFD, we analyzed the effects of angle of attack, gust ratio, frequency, and gust type on total pressure recovery and distortion index. Results reveal significant hysteresis in performance recovery post-gust. Increasing angle of attack amplifies response fluctuations, with recovery variation reaching 4.37% at 8？ AoA. Gust ratio governs response magnitude, while frequency modulates it through spatial wavelength effects. Sinusoidal gusts induce more intense cyclical variations than 1-cos gusts. The exit flow field evolution shows strong phase-coupling with gust excitation. These findings elucidate the unsteady flow mechanisms and provide essential insights for dynamic stability evaluation of such inlets under realistic atmospheric conditions.
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