Numerical Simulation And Study Of Hot-air Anti-icing On The Aero-engine Intake Strut

When the aircraft passes through the clouds composed of supercooled water droplets,ice accretion may occur at the intake position of the aero-engine.The ice accretion in these areas will limit flow rates of air into the aero-engine,resulting in the performance degradation of the engine,or loss of ice accumulation and causing engine failure.The strut is one of the air-intake components of aero-engine,which is prone to ice accretion.In this paper,aiming at the ice accretion phenomenon in the typical type of aero-engine intake strut,the CFD fluid-solid coupling heat transfer simulation technology is applied to carry out the numerical simulation research on the temperature field characteristics of the strut under conditions of hot-air anti-icing,which provides support for the structural design and improvement optimization of the hot-air anti-icing of the aero-engine intake construction.First of all,a CFD analysis model of thermo-fluid-structure coupling analysis is established for the typical engine intake structure.Including reasonable simplification of the strut geometry,establishment of the analysis domain grid and mesh sensitivity analysis,turbulence model selection,model verification,etc.,which lays the foundation for subsequent simulation and analysis of temperature field at different working conditions and changing the intake structure of the strut.Secondly,the research scope of five parameters such as the temperature and speed of the incoming cold-air,the temperature and flow rate of the hot-air heated by the strut is determined.A CFD analysis model for the temperature field analysis of the strut under different working conditions was established,and the internal and external flow field characteristics of the strut and the surface temperature field distribution characteristics of the strut under different working conditions are compared and analyzed.The simulation results show that the temperature and velocity of the incoming cold-air do not affect the cooling and heat transfer form outside the strut,and have little effect on the flow of hot-air inside the strut.The mass flow rate and temperature of the hot-air have great influence on the distribution of hot-air flow inside the strut and the surface temperature.Finally,a series of CFD thermo-fluid-solid coupling models with different impingement hole sizes inside the strut and arrangements models,as well as different air-film gap sizes and arrangements were established,and the influence of the internal structure of the strut on the flow field and surface temperature field was compared and analyzed.The simulation analysis results show that when the size of the impingement hole is reduced,the surface temperature of the intake strut is much higher than that of the other two structures;when the impingement hole is enlarged and reduced,it basically has no effect on the distribution law of the surface temperature of strut;By changing the arrangement of the apertures along the flow direction can improve the low surface temperature of the root section of the strut;moving the impingement hole forward is beneficial to increase the surface temperature of the structure,while the backward movement of the impingement hole will not affect the surface of the strut temperature.When the size of the air-film gap is reduced or enlarged,it does not affect the flow of hot-air inside the strut and the temperature distribution of the front edge;the forward and backward movement of the air-film gap has little effect on the surface temperature of the strut.