Aircraft Acceleration Prediction Due to Atmospheric Disturbances with Flight Data Validation

A methodology to predict aircraft transient motion resulting from flight within a turbulent atmospheric environment, coupled with validation using flight-test data, is explored. A family of four linear dynamic models is developed for describing the normal acceleration throughout an aircraft cabin due to vertical gust excitation. The four models successively build upon each other by incorporating higher fidelity gust penetration effects while simultaneously maintaining a unified modeling framework. Six wind fields reconstructed from flight-test data are used to excite the vehicle models. Simulation responses are compared with forward, center, and aft accelerometer data streams recorded during the test. Although significant differences are known to exist between the simulated dynamics and flight vehicle, all models tend to approximate adequately primary features in the nonlinear flight data. However, higher-order features in the flight data can not be reliably replicated in the simulations due to these differences. One model consistently tends to out perform the other models, both qualitatively and quantitatively, and corresponds to the highest fidelity gust penetration model. This particular model is recommended as an acceptable alternative to a higher fidelity, nonlinear full simulation when approximating the acceleration response for the intended application.