Simulation And Experimental Research On Thermal Bow Vibration Characteristics Of Aeroengine Rotor

The working conditions of the aero-engine rotor are extremely special.The influence of temperature must be considered when studying the structure and performance of the engine.The change of temperature affects the overall performance of the machine to some extent.Therefore,the research on the flow-heat-solid coupling of aero-engines has become a top priority.In the numerical simulation of the temperature field of the aero-engine rotor,it is often plagued by its complicated structure.The blades on the turbine or compressor mainly affect the aerodynamic performance of the engine.For the study of the heat transfer process,the blade increases the heat transfer.However,the complex structure of the blade and the blade root greatly reduces the computational efficiency.The number of blades is large,the structure is diverse,and the overall structure of the rotor-blade is complicated;considering the temperature analysis of the rotor structure of the blade takes time.In many studies,regardless of the blade or the effect of the simplified blade,the temperature results of the rotor structure have a greater impact.In order to simplify the blades of aero-engines,the equivalent heat transfer model of blades and blade roots is established.The equivalent radius of individual blades is calculated by the heat exchange between a single blade and a watershed,and further extended to the entire blade.For the blade roots of two commonly used aero-engine blades,the concept of heat resistance in heat transfer is introduced,the contact thermal resistance between the blade root and the blade root groove is considered,and the dovetail type is simplified according to the characteristics of series connection and parallel connection in electricity.The relationship between the root resistance of eucalyptus roots and the equivalent model of the two leaf roots were derived.Combined with the equivalent radius of the blade,the mathematical relationship of the equivalent ring radius of the dovetail root and the eucal yptus root is given.According to the calculation of the equivalent heat transfer radius of the simulated compressor wheel and the simulated turbine wheel,the finite element model of the aero-engine rotor is established,meshed and simulated,and the initial temperature distribution of the rotor is calculated by the steady state process.The difference between the natural convection cooling and the rotor temperature distribution after forced convection cooling is simulated and the thermal deformation of the rotor is calculated based on this temperature gradient.The aero-engine thermal bending test bench was designed to simulate the occurrence of thermal bending.The temperature distribution of the rotor was measured after natural convection cooling and forced convection cooling,and the accuracy of the simulation was verified.According to the calculated thermal bending deformation of the simulation,the vibration characteristics of the rotor after different bending states of thermal bending are simulated.On the basis of the thermal bending test,the vibration test of the hot bending rotor is further completed,and the test results are analyzed.