The Reverse Design Based On Fluid-structural Interaction Theory For Aircraft Engine Fan Blades

The performance of turbofan engine has an important impact on the integral performance of the engine,while the shape of fan blade is one of the most important parameters affecting the aerodynamic performance and structural performance of fan blades.When working, the manufacturing blade that designed by traditional design method will be deformed due to the role of load, the deformation makes it deviates from its optimum design.Therefore, it is very important to do reverse design for fan blade by considering the structure deformation and the aerodynamic interaction.This paper takes NASA Rotor 67 fan blades as the research object, using ANSYS, NUMECA, MPCCI, UG software as the analysis platform, do the research of fan blade reverse design.The research process involves aerodynamic performance analysis,fluid-structure interaction analysis,finite element analysis and reverse design for Rotor 67 fan blade.The specific contents of this paper are as follows:(1)Based on the powerful geometric modeling functions of UG software,use its modeling function of UG CAD module,complete the creation of working Rotor 67 blade model(the model of original hot blade) by the bottom-up modeling approach. The original hot blade model was created to be used for the following analysis, fluid structure coupling analysis and total deformation analysis of the blade.(2)Based on the fluid-solid coupling theory, the ANSYS, NUMECA and MPCCI software were used to complete the aerodynamic analysis of the blade,obtain the blade surface coupling aerodynamic pressure data. In the UG environment, considering the centrifugal force and aerodynamic force, the deformation of the blade was analyzed, obtain the total deformation of the blade during the working process.(3)Programming by C/C++ language to create blade geometry model data files which can be identified by UG software, adding back the deformation amount to the original hot blade model to get the reverse design fan blade model.(4)Analyze the deformation of the reverse design fan blade model, get its working blade model--the hot reverse design blade model, get the difference between the hot reverse design blade model with the original hot blade model, and use it make modifications to the reverse design blade model,after a number of iterations, get the reverse design blade model when the difference between the hot reverse design blade model with the original hot blade model are 0.018178 mm, finally, the rationality of the reverse design blade model is analyzed by means of the method of checking the aerodynamic performance of the hot reverse design blade model. Aerodynamic analysis results showed that the deviation rate between the original hot blade model and the hot reverse design blade model is 1.74%, the pressure ratio deviation is 0.674%, the efficiency deviation for 1.229%, the aerodynamic performance parameters of the two are in good agreement, which indicates that the hot reverse design blade model can meet the performance requirements.Through the reverse design of the NASA Rotor fan blade, explored a method to achieve the fan blade reverse design research, get the maximum difference value between the hot reverse design blade model and the original hot blade model when the hot reverse blade model meets the aerodynamic agreement.This paper has certain reference value to the follow-up reverse design research.