Numerical Simulation Of Airflow Field For The Precision Centrifuge

Precision centrifuge is a special device for calibration of inertial navigation accelerometer, it corrects the accelerometer by applying a series of acceleration loads. Because the inertial navigation accelerometer precision directly affects the accuracy of the navigation system, it has the value of research and application to improve the precision acceleration loads.In this paper, we combine with the precision centrifuge of China Academy of Engineering Physics to study the flow field characteristics of the precision centrifuge by numerical simulation and theoretical derivation, the concrete contents include:(1) This paper shows the effect of turbulence model, the near wall treatment, three dimensional effect and mesh size on the simulation results by the study of flow around bluff body, the simulation method of flow field of precision centrifuge is established.(2) By comparison between simulation and theory resolution, this paper select the appropriate numerical method for the precision centrifuge; This paper study the relationship between the wind resistance moment and rotational speed by numerical simulation and theoretical derivation, the experimental results show the feasibility of the numerical simulation method. Through theoretical analysis and numerical simulation, we study the relationship between wind resistance moment and the chassis size.(3) By means of numerical simulation, the law of wind resistance moment fluctuation under different operating conditions is established; A dome is designed for the precision centrifuge to reduce the wind resistance moment fluctuation to 25%; In this paper, study shows that the fractional error of acceleration loads has a linear relationship with wind resistance moment fluctuation by theoretical derivation.(4) The shape sensitivity of the windward side of a bluff body is calculated by the Adjoint Solver; The best gas dynamic shape bluff body is obtained by the sensitivity optimization method, this method complete the optimization of bluff body aerodynamic shape by mesh modify. Compared with the traditional method, this method is more efficient.(5) Precision centrifuge is used in aerostatic bearing, this study two methods of simulation for aerostatic bearing:solve the Reynolds equation by using the finite difference method based on MATLAB and simulate the air flow field of aerostatic bearing based on Fluent; Based on the simulation results, this paper compares the advantages and disadvantages of the above two methods;(6) Based on the calculation results of aerostatic bearing’ flow field, this paper presents three simple calculation methods for the critical speed of precision centrifuge, and analyzes the factors affecting the accuracy of the calculation methods.