No abstract

Atmospheric ice accretion on structures is a problem of fundamental importance to a number of industries. Examples of engineering problems caused by ice accretion involving aircraft, power transmission lines, telecommunication towers, electrical railway contact-wires, and other structures. Under atmospheric icing conditions two basic types of ice may form; rime or glaze. The supercooled micro-droplets in clouds are an important factor in icing. The objective of this study was to develop a new experimental method to investigate a single supercooled micro-droplet freezing process, in order to better understand the mechanism of rime or glaze ice accretion. The experimental device and principles are described in this paper. The experimental set has two small cold rooms, which is separated by a board with a central hole. A droplet with diameter of 15∼40 μm, temperature of 0∼−5°C was levitated in the cold air stream by electrostatic force. A CCD camera tracked its trace. The air temperature is from 0∼−10°C, the micro-droplet diameter is from 15∼40μm, and its temperature is from 0∼−5°C in the experimental study. This article focused on the experimental set and the experimental principles, and the next article will focus on the experimental data analysis.

No abstract

No abstract

As the interest towards wind energy becomes a great concern, it's significant to model wind speed accurately and smoothly for the simulation of wind power system in laboratory. In view of this, an improved wind speed model with 4 components has been established by Matlab/Simulink platform, which shows well performance in describing real wind characteristics of gust, gradual change wind and random noise wind. To further testify its accuracy and reliability, it's indispensible to consider real wind conditions. Based on the wind speed data in YunNan Province of China, a comprehensive model system has been built. Compared with random noise wind speed model, the results show that the 4component composite wind speed model can provide a more desirable modelling to simulate real situation of gust, gradual change wind and random noise wind. Therefore, combined wind speed model can be an effective and practical part in the wind power experimental platform.