Fluid-thermal-solid multi-field numerical simulation of aircraft gear transmission based on microcrystal model

ObjectiveTo simulate the meshing state of gear teeth under actual working conditions and reveal the meshing transmission mechanism of gears under actual working conditions, the flow field model of gear meshing process was established based on the multiphase flow model and the dynamic mesh method.MethodsThe flow field model was calculated and solved. The initial calculation parameters such as oil pressure, tooth surface temperature and convective heat transfer coefficient were provided for the thermal-solid coupling analysis of titanium alloy gears. The grain anisotropy distribution information inside the gear was introduced through the nanoindentation. Finally, the gear fluid-thermal-solid multi-field microcrystal model was established based on the Voronoi method and the Python secondary development, and the flow field, temperature field and stress field during the gear meshing transmission were calculated. The difference between the traditional homogeneous finite element model and the microcrystalline heterogeneous finite element model in the maximum contact stress and peak temperature of the tooth surface was compared and analyzed.ResultsThe results show that the meshing thermal stress calculated by the microcrystalline model is smaller, and the stress distribution is more dispersed than that by the traditional finite element model. Because the influence of grain inhomogeneity on the temperature and stress in the meshing process is fully considered in the modeling, the microcrystalline model can more truly reflect the meshing state of the gear teeth in the actual working condition.