结冰风洞液态水含量测量方法研究  

A Method of Liquid Water Content Measurement in Icing Wind Tunnel

作　　者：易贤[1] 桂业伟[1] 肖春华[1] 黄志祥[1] 

机构地区：[1]中国空气动力研究与发展中心计算所空气动力学国家重点实验室,四川绵阳621000

出　　处：《科技导报》2009年第21期86-90,共5页Science & Technology Review

基　　金：国家自然科学基金项目(10672174;10772191)

摘　　要：液态水含量是影响结冰形状和结冰类型的重要结冰云雾参数。获知结冰风洞中的液态水含量,是得到定量结冰风洞实验结果的基础。本文提出了一种采用数值计算和结冰风洞实验相结合的手段,测量结冰风洞中液态水含量的方法。该方法首先采用拉格朗日法数值计算水滴运动轨迹,得到物体表面水滴的总收集系数;其次,计算不同液态水含量所对应的结冰质量,建立液态水含量与结冰质量的关系曲线;在此基础上,进行结冰风洞实验,测量实验得到的结冰质量,通过在液态水含量与结冰质量的关系曲线上进行插值,进而得到实验液态水含量的大小。用本文提出的方法进行结冰风洞液态水含量测量,只需一般的质量测量工具即可进行,操作方便,成本低廉,避免了常规的液态水含量测量或标定需要专门设备的不足。采用25和35m/s两种速度条件对0.3m×0.2m结冰风洞的液态水含量进行了测量,两种条件得到的结果一致,相差不超过0.01g/m3,说明本文提出的方法是合理的。研究显示,0.3m×0.2m结冰风洞在开启一个喷嘴时,液态水含量值在0.15g/m3左右。Liquid Water Content （LWC） is an important parameter in the process of aircraft icing. Ice shape and type can be greatly affected by LWC. For a valid icing wind tunnel test it is necessary to obtain the value of LWC before test. The present paper proposes a method to measure LWC in an icing wind tunnel, which combines both nmnerical and experimental results. Firstly, droplet trajectories are computed with a Lagrangian method to obtain the total collection coefficient of water droplet. Secondly, ice mass is computed, and the curve relating LWC with ice mass is obtained. Lastly, the experimental results of ice mass are used to determine the value of LWC from the curve. It is a convenient and economical method to measure LWC without the need of expensive and complex devices and with only an instrument for mass measurement. The value of LWC, in an icing wind tunnel with a 0.3 m×0.2 m test section, is then obtained. The results from test speeds of 25 m/s and 35 m/s are found in agreement, with a difference of not more than 0.01 g/m^3, which validates the method. The study shows that when one nozzle is opened, the LWC value in the 0.3 m×0.2 m icing wind tunnel is about 0.15 g/m^3.

关 键 词：飞机结冰 结冰风洞 过冷水滴 液态水含量 总收集系数 拉格朗日法 

分 类 号：V211.74[航空宇航科学与技术—航空宇航推进理论与工程]