Multi-field Coupling Simulation Of Nickel-based Alloy Turbine Blade Composite Cooling Structure

The aviation,aerospace,marine and terrestrial power generation industries use gas turbines and auxiliary engines as the main equipment for power generation.At present,with the reorganization and establishment of CNAF Group,the landing of two major aircraft projects and the development of gas turbine technology have become the key to China's development of aircraft power,ship power,and energy power.Current design workers mainly design,modify,and redesign the turbine blade model based on the simulation results of the flow field and temperature field of the turbine composite cooling structure.However,with the increase of the temperature before the turbine,the design of the cooling structure becomes more and more complicated.Various new materials(directional solidification alloys,single crystal alloys)are applied to the manufacture of turbine blades.The simulation results for a single temperature field and flow field are Not enough,we need to synthesize multiphysics data to come up with better designs and modifications.In the aspect of gas-heat coupling verification,this paper uses the Mark II blade as the research object,and compares and analyzes the turbulent-flow simulation results and experiments of five turbulence models(k-?,k-?,sst,ssg,and BSL Reynolds Stress).result.Considering the model and actual laboratory computing resources in this paper,the k-? turbulence model is selected as the turbulence model for the full three-dimensional gas-heat coupled simulation of the turbine blade model.Under the ANSYS-CFX platform,a three-dimensional gas-heat coupled calculation was performed on a gas turbine primary turbine blade that already had a preliminary design.The temperature field cloud map and the flow field cloud map were analyzed,and seven modifications were proposed.After the modification is completed,the CFX full three-dimensional gas-heat coupled simulation is performed on the modified results.From the perspective of temperature distribution and flow,the modification has a significant effect.For the prototype model and modified model,the thermal-solid coupling calculation was performed based on Abaqus commercial finite element numerical software.The nominal stress distribution of the prototype and modified turbine blade blade body was obtained.The thermo-mechanical coupling was programmed in the Fortran language,and the Abaqus finite element model file was written in Matlab.From the standpoint of nominal stress field,the previous seven modifications have a certain effect,but both the prototype and the modified blades have a common problem,that is,the heat exchange at the cold air inlet is too intense,which leads to local heat in the area.Stress concentration.Based on the finite-deformation crystal plastic slip theory,the distribution cloud diagram of the maximum shear stress of the prototype and modified blade aerofoils was calculated by the Abaqus subroutine.From the point of view of the maximum shear stress field,the previous modification based on the results of the flow heat exchange has certain effects.The peak value of the maximum shear stress of the modified blade model has a certain decrease compared with the prototype,and the high stress area also has a certain decrease.In this paper,it is pointed out that the modified Ni-based alloy turbine blades still need to conduct in-depth research on the more obvious positive and negative maximum shear stress cross-connections and carry out further improvement designs.