Test on ice accretion and shedding of transonic fan blades in ice wind tunnel environment

To investigate the laws of surface ice accretion and ice shedding characteristics of transonic rotor blades under different conditions, and to obtain the ice shedding position and cross-sectional structure, study takes transonic fan rotor blades as the research object. Based on an ice wind tunnel system with natural low temperature, test studies on ice accretion and shedding of rotor blades were carried out under typical icing conditions. The results show that ice accretion occurs on both the suction surf-ace and pressure surface of the transonic fan rotor blades, and ice shedding starts simultaneously from both surfaces of the blades. As the ambient temperature decreases, the ice shape on the blade surface changes from glaze ice to mixed ice, and then to rime ice. Ice shedding is affected by blade rotational speed, rotational acceleration rate, and ambient temperature; the time required for ice shedding and the degree of ice shedding vary under different conditions. When the ambient temperature is constant, as the ice-accreting rotational speed of the blade increases, the ice-shedding rotational speed increases monotonically, while the ice-shedding time decreases monotonically. Meanwhile, the ice shedding amount on both the pressure surface and suction surface of the blade increases with the increase of blade rotational speed. When ice shedding is conducted by increasing the rotational acceleration rate, as the rotational acceleration rate increases, the degree of ice shedding on the blade surface increases monotonically, while the ice shedding time decreases monotonically. For ice shedding under different temperatures, as the temperature decreases, the degree of ice shedding decreases, and the time requirde for ice to shed from the blade surface is extended. Within a certain range, the prediction model for ice shedding rotational speed established based on test data canaccurately predict the ice shedding rotational speed under different operating conditions.