在循环水槽中对船长为1.725和3.450 m的KCS船模分别进行船模阻力试验与伴流测量试验,通过对比试验结果总结模型尺度对阻力的影响;开展3.450 m 的KCS船模在无限水域/循环水槽中的数值模拟,通过对比数值结果总结阻塞效应对阻力的影响,验证简化田村公式的修正效果;进行不同湍流强度循环水槽条件下3.450 m KCS船模绕流场的数值模拟,总结湍流强度对阻力的影响。
The Air Traffic Management system is under a paradigm shift led by NextGen and SESAR. The new trajectory-based Concept of Operations is supported by performance-based trajectory predictors as major enablers. Currently, the performance of ground-based trajectory predictors is affected by diverse factors such as weather, lack of integration of operational information or aircraft performance uncertainty.Trajectory predictors could be enhanced by learning from historical data. Nowadays, data from the Air Traffic Management system may be exploited to understand to what extent Air Traffic Control actions impact on the vertical profile of flight trajectories.This paper analyses the impact of diverse operational factors on the vertical profile of flight trajectories. Firstly, Multilevel Linear Models are adopted to conduct a prior identification of these factors. Then, the information is exploited by trajectory predictors, where two types are used: point-mass trajectory predictors enhanced by learning the thrust law depending on those factors; and trajectory predictors based on Artificial Neural Networks.Air Traffic Control vertical operational procedures do not constitute a main factor impacting on the vertical profile of flight trajectories, once the top of descent is established. Additionally, airspace flows and the flight level at the trajectory top of descent are relevant features to be considered when learning from historical data, enhancing the overall performance of the trajectory predictors for the descent phase. 相似文献