# Experimental Study on the Effect of Different Parameters on Rotor Blade Icing in a Cold Chamber
## 1 Introduction  
With the development of modern helicopters, all-weather flight is one of the most important goals that is being pursued by the new generation of helicopters worldwide. All-weather flight requires that the helicopter rotor can work normally under icing weather conditions. Therefore, icing phenomenon is one of the major problems in rotor design [1, 2]. The main methods of helicopter rotor icing research include experimental research and numerical simulation [3, 4], and the experimental research includes flight experiments and ground experiments. Although the experimental research needs a large amount of money and time, the experimental results are more intuitive. The experimental results can verify the numerical simulation method, which is helpful to improve the calculation accuracy of the rotor numerical method. Some phenomena that cannot be simulated in the numerical method can be observed during the experimental process. In icing airworthiness certification, experimental verification is also an important part [5, 6]. Flight experiment is the main method to research the rotor icing problem in the early stage [7]. Its disadvantage is that it needs to search for natural icing weather conditions, which has high risk coefficient and poor repeatability. Nowadays, flight experiment is generally used as the last method in airworthiness certification to verify the performance of rotor anti-icing and de-icing systems. Because the rotor blades rotate around the axis, icing wind tunnels used for fixed wing is difficult to meet the space size requirements of rotor test. If the rotor model is reduced to a suitable size to match the small icing wind tunnel, the three-dimensional rotation effect will be greatly affected [8, 9]. In order toovercome the shortcomings of flight experiment and icing wind tunnel experiment, the rotor icing experimental platform is usually built in the cold environment, such as McKinley climate laboratory in the United States, where full-scale helicopter rotor icing experiments can be carried out [10; 11]. Many rotor icing experimental results have been obtained. The U.S. military has carried out a comparative test of rotor icing under artificial icing conditions and natural icing conditions. The results show that the outcomes of artificial icing tests and natural icing tests are very similar [12]. Office National d'Etudesetde Recherzhes Aerospatiales (ONERA) has carried out several icing tests of rotor model in Snow & Ice Management Association (SIMA) icing wind tunnel and compared them with flight test results. The flight and icing wind tunnel test data were collected and sorted out, and a database was established [13]. [PERSON] et al. [14] studied the scaling method of helicopter rotor icing and verified it with the NACA 0012 airfoil model. The results show that the ice shapes before and after scaling are in good agreement. [PERSON] et al. [15; 16] built an icing experimental platform in the cold environment of Penn State University and studied the measurement method of liquid water content in the cold environment. The icing process of wind turbine is similar to that of rotor blade. [PERSON] et al. [17] carried out the icing experiment of a wind turbine blade in an icing wind tunnel, measuring the ice shapes under different wind speeds and angles of attack. [PERSON] et al. [18] studied wind turbine blade icing under natural icing conditions and discussed the dynamic response of the short-term power loss of wind turbine. In this paper, in order to study the effects of different parameters on the rotor icing, we studied the method of rotor icing experiment. The small-scale rotor icing experimental platform in the cold chamber was built, and the related devices were introduced. The rotor icing experiments under various conditions were carried out. The experimental results were analyzed and the effects of different parameters on rotor icing were obtained.