Research On The Methods Of Parameter Measurement For Small Icing Wind Tunnels

The icing wind tunnel is an important ground simulation equipment for the study of aircraft icing and anti-icing/de-icing,which is used to simulate the parameter indexes of aircraft wing icing.Meteorological parameters mainly include atmospheric temperature,pressure,liquid water content,and the median volume diameter.It not only determines the possibility of aircraft icing,but also determines the type and nature of icing.In addition,the flight speed of the aircraft also has a great influence on the aircraft icing.Air speed and meteorological parameters are the keys to the test of the icing wind tunnel,so the accurate measurement of parameters has become very important.An experiment parameter monitoring system consisting of an upper computer and a lower computer was designed for a small natural low-temperature icing wind tunnel.The system can display and store values of temperature and humidity,wind speed,and pressure,providing data support for subsequent icing studies.According to the existing research conditions,the highspeed industrial camera was selected as the acquisition device for water droplet images,and the water droplet images were processed and measured in batches using Image-pro plus6.0.The droplet diameter data for this experiment are obtained,and the frequency distribution and volume fraction distribution of the water droplet diameter in the experiment are calculated.The error analysis experiment shows that the error of this measurement method is ±3.2%,which is in line with the recommendation of Kashdan J T that the measurement error of the diameter of about 100?m is less than 5%.The value of the median volumetric diameter of the water droplets was obtained by interpolating the cumulative volume distribution using Akima interpolation.Finally,the liquid water content of the small icing wind tunnel was measured using the ice knife method and the water collection method,respectively.In the meanwhile,the Euler method is used to calculate the efficiency in collection of the icing blade.It is found that the value of liquid water content is basically consistent with the trend of water pressure change by comparing the measurement data of the two methods,and the reasons for the difference between the liquid water content data of the two measurement methods are given.