## 5 Conclusions  
In this study, a test platform for ice-water propeller milling was constructed in a large circulation water channel, and an ice-propeller milling test in air and ice-water propeller milling test under atmospheric pressure and decompression conditions were conducted. The influence of water and cavitation on the load and bearing force of the propeller and single blade was analyzed. The main conclusions of this test are as follows:  
1. In the ice-water propeller milling process, the presence of water causes propeller thrust and axial force generated by ice to act in opposite directions, and their combined action results in loss of propeller thrust. The water and ice have the same direction of influence on the propeller torque, and the combined action of the two causes the propeller torque to increase. The thrust and torque of the single-blade mixed load increased significantly in the presence of water. The occurrence of cavitation reduces the thrust and torque of the propeller and single-blade mixed load. 2. When ice, water, and propeller interact under the decompression condition, the blockage effect of the ice block generates blade sheet cavitation. The larger the axial milling depth of the ice-propeller, the larger the area of sheet cavitation on the surface of the non-milling blade, and the thicker the tip vortex filament; moreover, the closer the blade is to the blocked area, the more evident the increase in the area of sheet cavitation on the blade surface. Compared with atmospheric pressure, the decompression environment causes the blade tip vortex to collapse in the blocked area, and the tip vortex size of the propeller wake in the blocked area evidently increased. 3. In the analysis of the bearing forces of the propeller and blade, the presence of water causes the fluctuating amplitudes of propeller thrust and blade bearing force to increase significantly, but it has no evident effect on the fluctuating amplitude of the torque under mixed load of the propeller. Cavitation results in an increase in thrust fluctuating amplitude and a decrease in tangential force fluctuating amplitude of the single blade. 4. During the ice-propeller milling in air, the higher the propeller rotational speed, the smaller the peak values of the axial force and torque of the propeller and single blade, but the greater the fluctuating amplitudes of the axial force and torque of the propeller and single blade. At atmospheric pressure, with an increase in the advance coefficient, the peak values of the thrust and torque of the propeller and single blade as well as the fluctuating amplitude of the propeller torque decrease, whereas the fluctuatingamplitudes of the propeller thrust and the single-blade thrust and torque increase. Under decompression conditions, the smaller the cavitation number, the smaller the peak values of the thrust and torque of the propeller and single blade, but the larger the fluctuating amplitudes of the thrust and torque of the propeller and single blade. The results of this study provide experimental guidance and technical support for improving comprehensive designs considering propeller efficiency and ice load-carrying capacity and improving the safety and speed of ice-going ships. In this experiment, the ice asymptotic motion was constrained, and the degree of freedom of the ice was not released. In the future, an experimental study on the load and cavitation of the propeller will be performed when the ice in free motion is close to the propeller owing to the suction of the propeller. Conducted all experiments, P.X. and C.W. ; designed the experiments and wrote the manuscript, P.X. ; data curation, L.Y. All authors discussed continuously and contributed to the writing of the manuscript. All authors have read and agreed to the published version of the manuscript. This research was funded by the National Natural Science Foundation of China (Grant Numbers 51809055 and 51909043) and China Postdoctoral Science Foundation (Grant No. 2020M681082). Not applicable. * [PERSON] et al.