Three Dimensional Numerical Simulation And Experimental Study On Anti-icing Of Aero-engine Strut

When an aircraft flies the through clouds containing super-cooled water droplets,ice accretion will occur in the inlet of aero-engine,such as struts and guide vanes,which may affect the aerodynamic performance of the engine even damage the whole engine seriously,seriously threatening flight safety.At present,most of the research on anti-icing at domestic and overseas focuses on uniform wing,while there are few anti-icing studies for the inlet of the engine with significant threedimensional features.In order to improve the anti-icing design ability of the engine's inlet and verify the accuracy of the anti-icing calculation program of the three-dimensional water film flow developed by the research group independently,three-dimensional numerical simulation and experimental study on the anti-icing of the engine inlet strut in the ice wind tunnel test section are carried out in this paper.Based on this,a validated calculation program is used to carry out numerical research on the ice accumulating characteristics of the strut in inlet casing of the turbo-shaft engine.Firstly,this paper established the computational model of thermal air ice protection for the real size turbo-shaft engine inlet strut in the ice tunnel test section and numerical simulations were carried out in the three cases of ice and incomplete evaporation and anti-icing for the ice accumulation and complete evaporation prevention under the maximum icing condition using the self-developed threedimensional anti-ice calculation program The calculation results show that the maximum local water collection coefficient of the leading edge of the strut is 0.85 and the maximum accumulated ice thickness is about 6mm.;in the case of complete evaporation anti-icing,there is no water film on the surface of the strut,and the temperature decreases from the leading edge to the trailing edge,with a maximum of 107?and a minimum of 34?;in the case of incomplete evaporation and anti-icing,the largest thickness of the water film on the surface of the strut is near the stagnation point of the leading edge,which is 0.11 mm,and the temperature is also decreasing from the leading edge to the trailing edge,from 78?to 26?.The numerical simulation also provides a design reference for the hot gas supply temperature and flow rate required for the above two anti-icing conditions.Secondly,based on the experimental model of the inlet strut,the hot air anti-icing test device of the inlet strut ice tunnel is designed and manufactured,and the experiment of ice accretion,complete evaporation anti-icing and incomplete evaporation anti-icing are carried out under the same icing conditions as the previous numerical simulation.The results show that under the condition of ice accretion,the maximum ice thickness is about 10mm;under the condition of complete evaporation and anti-icing,the surface of the strut is waterless,and the temperature decreases from the leading edge to the trailing edge,from 100 °C to 31 °C;under incomplete evaporating anti-icing condition,continuous water film appears on the surface of the front impact zone,which breaks into streams and is blown away by air in the form of water droplets,and the surface temperature of the strut decreases gradually from the leading edge to the trailing edge,from 85? to 20?.Compared with the experimental data,the overall trend prediction results of the above numerical simulations are accurate,indicating that the existing anti-icing calculation program has good calculation accuracy.Finally,in order to obtain the ice accretion characteristics of the inlet strut in the turbo-shaft engine affected by the intake runner,the numerical calculation of the ice accretion characteristics of the inlet strut of the inlet casing including the integral particle separator was carried out by using the verified three-dimensional anti-ice calculation program.The results show that 99.4% of the water droplets in the inlet casing enter the sweeping airflow,and the icing parameters show obvious circumferential non-uniformity in the upstream of the leading edge of the strut.For the four struts downstream of the main channel,the front edge of the strut which is closest to the volute's starting position is impacted by significant water droplets.The maximum water collection coefficient is 3.8,and the maximum ice thickness is about 8 mm.The results of this paper can provide a basis for the anti-icing design of the inlet strut of turbo-shaft engine considering the influence of the integral particle separator.