飞机地面结霜的分析与预测

发布时间：2018-05-03 12:11

本文选题：结霜 + 生长模型　；参考：《中国民航大学》2015年硕士论文

【摘要】：飞机在地面的结霜会对飞机的飞行性能产生不利影响,还会降低飞机的除冰效率。结霜现象的发生环境复杂,存在着多种不确定因素。为了保证飞机的飞行安全和机场的运作效率,有必要对飞机的地面结霜进行准确分析与预测。针对以上问题,本文对飞机的地面结霜进行理论分析,建立霜层的生长模型并对飞机的地面结霜进行预测。主要内容如下:本文分析了机翼表面结霜的传热与传质的过程,推导了传热传质的平衡方程。提出了一种新的霜晶树模型描述霜层的结构与生长过程,建立了霜层的生长模型,通过对模型参数进行分析,了解了生长模型的变化趋势。建立了飞机地面结霜环境模拟实验系统,对不同温度、相对湿度和水分子形态的实验数据进行了分析,了解影响飞机结霜过程的环境因素。研究不同环境条件下生长模型的参数、霜层平均密度和平均导热系数的变化趋势,了解不同环境条件下的霜层生长模型曲线与结霜生长速率的变化。本文提出了一种新的嵌套式多项式预测模型,对不同模拟环境下的飞机地面结霜进行短期预测。由于多项式预测的局限性和扩展性较差,提出了多项式与生长模型分段组合预测的方法提高了预测的精度。基于灰色预测原理建立了三种飞机结霜的灰色预测模型:OSFDGM(1,1)模型,DGM(1,3)模型和灰色组合模型。通过与多项式组合模型对比,分析了在不同的室内模拟结霜环境中预测模型的适用性和精度。基于室外真实结霜提出了分段组合预测模型,通过与灰色组合预测模型对比,发现早结霜中的期预测中,灰色组合模型预测精度较高。而在结霜的长期预测中,分段组合预测模型精度较高。
[Abstract]:Aircraft frost on the ground will have a negative impact on aircraft flight performance, and will reduce aircraft deicing efficiency. The occurrence environment of frosting is complex and there are many uncertain factors. In order to ensure the flight safety of the aircraft and the operational efficiency of the airport, it is necessary to accurately analyze and predict the frosting on the ground of the aircraft. In view of the above problems, this paper theoretically analyzes the ground frost of aircraft, establishes the growth model of frost layer and forecasts the ground frosting of aircraft. The main contents are as follows: the heat and mass transfer process of frosting on the wing surface is analyzed and the equilibrium equation of heat and mass transfer is derived. A new frost-tree model is proposed to describe the structure and growth process of frost-layer. The growth model of frost-layer is established. By analyzing the parameters of the model, the changing trend of the growth model is understood. An experimental system of aircraft ground frosting environment simulation was established. The experimental data of different temperature, relative humidity and water molecular morphology were analyzed to understand the environmental factors affecting the aircraft frosting process. The variation trend of the growth model parameters, the average density and the average thermal conductivity of frost layer under different environment conditions were studied, and the curve of frost layer growth model and the change of frosting growth rate under different environment conditions were studied. In this paper, a new nested polynomial prediction model is proposed to predict the frosting of aircraft ground in different simulation environments. Due to the limitation and poor expansibility of polynomial prediction, the method of piecewise combination of polynomial and growth model is proposed to improve the accuracy of prediction. Based on the principle of grey prediction, three kinds of grey prediction models of aircraft frosting are established: 1 / OSFDG / 1 / 1) model / DGMN / 1 / 3) model and grey combination model. By comparing with polynomial combined model, the applicability and accuracy of the prediction model in different indoor simulated frosting environment are analyzed. Based on outdoor real frosting, a segmented combined prediction model is proposed. By comparing with the grey combination prediction model, it is found that in the early frosting period prediction, the grey combination model has a higher prediction accuracy. In the long-term frosting prediction, the accuracy of segmental combination prediction model is higher.
【学位授予单位】：中国民航大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：V267

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