民机风挡防雾试飞环境分析  

Analysis of Flight Test Environment for Civil Aircraft Windshield De-fog

作　　者：白斌[1] 王向转[1] 李志茂[1] 

机构地区：[1]上海飞机设计研究院,上海201210

出　　处：《民用飞机设计与研究》2015年第4期48-50,67,共4页Civil Aircraft Design & Research

摘　　要：针对民机风挡防雾在§25.773(c)符合性验证过程中试飞试验环境条件过于宽泛的问题,通过分析机上风挡玻璃结雾的环境条件,确定了风挡防雾验证时的严酷条件高湿热环境(19g水/kg干空气,温度40℃)。对于高湿热条件在自然界难以实现的问题,提出了等湿降温和等设计保障等级两种不同的防雾试飞环境条件拓宽方式,并分别在标准大气焓湿图、相对湿度-环境温度图上给出了两种方式确定的风挡防雾试飞环境范围。通过这两种方式确定的风挡防雾试飞环境,已成功应用在某型号飞机风挡防雾试飞的适航符合性验证工作中。事实证明其是一种有效的试验环境拓宽方法。对风挡防雾试飞操作方式也进行了分析。This paper solves the problem that is met during civil aircraft windshield de-fog performance certifica- tion phase. As the environment defined in 25. 773 （c） is too general to conduct windshield de-fog flight tests, a high temperature with high humidity（ 19g water/kg dry air, ambient temperature 40℃ ） is introduced as the critical ease for windshield de-fog flight test after analyzing the principle of fogging on aircraft windshield. The paper proposes two different methods to define the de-fog flight test environment, hold humidity while drop temperature, or hold guaranteed class for system designing, as the dedicated high temperature with high humidity is hardly to meet in ambient air. Applicable curves for flight test are plotted on standard atmosphere enthalpy and humid chart, relative humidity-environment temperature chart respectively. The curves have been proved feasibly by other type aircrafts de-fog flight test, and the curves could be used to find an appropriate environment for civil aircraft wind- shield de-fog flight test. Flight test method for windshield de-fog is also discussed in this thesis.

关 键 词：风挡防雾 试飞试验 等湿降温 等设计保障等级 

分 类 号：V217[航空宇航科学与技术—航空宇航推进理论与工程]