Numerical Calculation Of Fluid-heat-solid Multi-physics Coupling Of Precision Centrifuge

Centrifuge is an important calibration device of inertial navigation accelerometer, and its error has a critical influence on the precision of accelerometer. Improving calibration accuracy of precision centrifuge has a great value on improving the precision of inertial navigation. Taking the precision centrifuge as the research object, then the structural deformation of rotator under the action of multi-physics coupling is calculated. In this paper, we study the flow field, temperature field and structure field coupling characteristics and factors of affecting thermal performance and structure deformation of precision centrifuge by theoretical derivation and numerical simulation. Specific contents are as follows:(1) Research on numerical methods of fluid-heat-solid multi-physics coupling. The mathematical model of coupling is presented, and the strong coupling algorithm and weak coupling algorithm to solve coupling-equations and its application is introduced. Some coupling solving methods at present is summarized and distinguished, based on it, three analysis methods, the direct method, sequence iteration method and the sequential coupling method, is defined and the relationship with strong/weak coupling algorithm is given. Then two similar coupling problem instances are simulated by using different analysis methods that is to compare calculation accuracy of three analysis methods, which provides a reference to numerical methods choice of multi-physics coupling calculation of precision centrifuge.(2) Numerical simulation of multi-physics coupling for the thermal deformation of precision centrifuge is divided into conjugate heat transfer and thermal structure coupling solution. The working principle and the relationship of multi-physics coupling of centrifuge are analyzed and the mathematical models of multi-physics coupling of centrifuge are established. Simulation modeling and computing contain geometric modeling; mesh subdivision, boundary condition setting, simulation technology application of MRF method and conjugate heat transfer, and solver selection, etc. The experimental value and calculated results show the relative error within 10%, verify the effectiveness of the simulation method. The results of centrifuge flow field, temperature field from the direct method and the sequential coupling method are compared and the calculation accuracy of methods is analyzed.(3) The research of influencing factors thermal performance and structure deformation of centrifuge. Study the influence of surface roughness and external heat source on the thermal performance of the centrifuge, the former including the calculation and analysis of heat transfer, flow in rough area and sectional velocity and temperature under different roughness; in addition, the effects of the rotate speed, inertial force and the combination of temperature rise of wind resistance and inertial force are studied and obtain the fitting equation between speed and rotator temperature and deformation and contrast structure deformation characteristics under different action.