Global optimization for ducted coaxial-rotors aircraft based on Kriging model and improved particle swarm optimization algorithm

To improve the operational efficiency of global optimization in engineering, Kriging model was established to simplify the mathematical model for calculations. Ducted coaxial-rotors aircraft was taken as an example and Fluent software was applied to the virtual prototype simulations. Through simulation sample points, the total lift of the ducted coaxial-rotors aircraft was obtained. The Kriging model was then constructed, and the function was fitted. Improved particle swarm optimization(PSO) was also utilized for the global optimization of the Kriging model of the ducted coaxial-rotors aircraft for the determination of optimized global coordinates. Finally, the optimized results were simulated by Fluent. The results show that the Kriging model and the improved PSO algorithm significantly improve the lift performance of ducted coaxial-rotors aircraft and computer operational efficiency.     

沈煤集团红阳三矿环境影响评价分析

环境质量现状调查与评价包括地表水环境质量现状调查与评价和地下水环境质量现状监测与评价,地表水环境质量现状调查主要有污染源调查,地表水环境质量现状监测。地表水环境质量现状评价采用单项水质参数法对地表水环境质量进行分析评价、对地表水监测值分析结果和工业场地排水水质现状分析与评价。地下水环境质量现状监测主要有地下水监(观)测点及监测项目、时间、分析方法。地下水环境质量现状评价主要采用矿井井下水排水水质利用例行监测值。     

非对称布局形式的涵道尾桨气动特性

针对现行涵道尾桨无法提供升力的缺点,提出一种非对称布局形式的涵道尾桨结构。通过理论分析和数值模拟的方法,对该涵道尾桨的拓扑结构进行气动性能研究,得出涵道尾桨升力、拉力和扭矩分别与飞行速度和开口角有关的结论。对称结构和非对称结构的涵道尾桨气动特性对比结果表明:该非对称布局的涵道尾桨不仅可以产生较大的轴向拉力,对飞行器姿态进行操纵,而且还产生一定的径向力,为飞行器提供额外的升力。总之,该非对称布局的涵道尾桨具有一定的可行性和应用价值。