Simulation Of Particle Deposition In Turbine Internal Cooling Passage And Optimization

As the range of civil airliners becomes increasingly wide,the amount of particle inhaled by aero-engine gets larger and larger.In addition,with increasing temperature at turbine inlet,the internal cooling passage becomes more and more complicated and the deposition phenomenon becomes more and more serious.Therefore,in order to simulate the particle deposition in turbine internal cooling passage more accurately,based on a newly built deposition model,numerical simulation research is conducted in order to find out the distribution and growth pattern of deposition.Certain geometric parameters of the cooling structure are also optimized in order to reduce the particle deposition in turbine internal cooling passage,which can extend the working life of turbine components.Firstly,the force analysis of the particles during transportation in the flow field is carried out.In addition,based on the gas-solid one-way coupling method and the Euler-Lagrange method,the motion equations and the heat transfer equations of the particles are established so that the particles can be traced in the following calculation.Secondly,the motion of particles during collision,adhesion and resuspension is analyzed.For the adhesion process,based on the existing deposition model and the eccentric sphere particle assumption,the new eccentric deposition model is created based on collision dynamics.And for the resuspension process,based on moment analysis,whether the deposited particles or blocks can be separated from the wall is determined.The analysis above can provide theoretical basis for the following non-stationary numerical simulation of deposition.Then,based on the theoretical model mentioned above,by applying UDF function and dynamic mesh function of FLUENT,a non-stationary numerical simulation scheme of deposition in turbine internal cooling passage is designed.And according to this scheme,the deposition growth and distribution are simulated.In addition,the variation of flow loss and heat exchanges of turbine internal cooling passage caused by deposition is also analyzed.Finally,referring to the previous calculation,the influence of geometric parameters,including the height of rib and the angle of upstream surface,on deposition distribution and thickness is analyzed in order to reduce the deposition in turbine internal cooling passage.