Research On Aerodynamic Multi-Dimensional Force Measurement Based On Combined Support

The high-performance aircraft plays an important role in the field of defense,and its design theory is very complicated.Generally,the aerodynamic multi-dimensional force is taken as an important design factor of the aircraft,and its accurate measurement is closely related to the force measurement method.Aiming at problems such as support system design and force measurement method selection for large-size and large-aspect-ratio aircraft models during wind tunnel tests,this thesis uses a piezoelectric sensor as the core test element,adopts a combined support method combining wire rope support and tail support,establishes the test system based on combined support to measure aerodynamic multi-dimensional force.Firstly,aiming at the problem of selecting a force measurement method for large-sized and large-aspect-ratio aircraft models during wind tunnel tests,an aerodynamic multi-dimensional force measurement method using a combined support is proposed.The relationship between the space angle of the wire rope and the two plane angles is established.Further,based on the principle of static equilibrium,a mechanical model based on combined support is established.Based on the a priori experiments and finite element analysis,the existing test system structure is improved to provide a basis for subsequent experiments.Secondly,after the sensor design is completed,in order to ensure that each sensor has the same input-output ratio,the piezoelectric sensors used in the test system are calibrated to obtain the static performance index.Data processing software is written using MATLAB to improve the efficiency of the solution.In order to obtain the performance index of the test system,the static calibration experiment of the test system is completed by means of weight loading.Aiming at the output coupling phenomenon in the calibration experiment,the main reason for this problem is analyzed and the experimental results are processed by the least square method to improve the measurement accuracy.Hammering experiments are carried out in the test system’s X,Y,and Z directions,and the amplitude-frequency characteristic curves of each direction are obtained.Finally,in order to evaluate the measurement results,the uncertainty of the test system is studied.The various uncertainties in the test system are classified according to the evaluation method and obtained according to the corresponding calculation method.Calculate the uncertainty transmission during the test process,and obtain the standard uncertainty andextended uncertainty of each dimension.The uncertainty of each dimension is analyzed,and the main factors affecting the uncertainty are studied.Based on the above research,for the large-sized,large-aspect-ratio aircraft model in the high Mach wind tunnel,the aerodynamic multi-dimensional force measurement method based on combined support is proposed.Furthermore,the feasibility of the method was verified by calibration experiments,which laid the foundation for the application of the method.The related theoretical work has important scientific research significance in improving the aerodynamic multi-dimensional force measurement technology of the aircraft and promoting the fusion manufacturing of sensors and models.