| Cylindrical gas film seals are applied to the auxiliary parts of the rotor system of aero-engines rotating at high speeds to improve the working efficiency of the whole equipment,the reduction of fuel consumption,and increase the durability and working life of related components.However,the severe vibration and thermal deformation of the rotor system produce large radial displacements that may cause the shaft sleeve and the floating ring to collide with each other,which brings challenges to the application of the cylindrical gas film seal in the rotor system.Based on the micro-gap dynamic pressure effect and the design of the air film seal structure of the large flexible support cylinder,this paper proposes a T-slot cylinder air film seal structure with bubbling flexible support,establish a numerical model of the bubbling flexible support structure,use fluid-solid coupling method to study the influence of the application of flexible support structure on the stress and strain of the seal ring in the cylindrical gas film seal,and apply the bubbling support structure to the cylindrical gas film seal to reduce The main research contents of the thesis are as follows:(1)Based on computational fluid dynamics(CFD)and fluid-solid coupling numerical calculation theory,a three-dimensional T-slot cylindrical gas film seal friction pair interface fluid and solid finite element model is established,and the end faces between the moving and static rings are numerically simulated.Fluid gas film obtains the pressure distribution law of the gas film,and the result shows that the pressure is in non-linear distribution;then the obtained pressure value is introduced as one of the boundary conditions into the static analysis of the end face of the seal ring,and the one-way weak fluid-solid coupling analysis realized by the automatic iterative calculation between the two contact surfaces.(2)A comparative analysis of the stress and strain of the seal ring is carried out between the bubble-type flexible supporting structure and the cylindrical gas film seal without flexible supporting structure,which provides a reference for the further optimization design of the large flexible cylindrical gas film seal.(3)Under different operating parameters such as pressure difference,rotational speed,eccentricity,etc.,the finite element analysis of the cylindrical air film seal with a bubbling flexible support structure shows that the maximum strain and maximum stress of the seal ring vary significantly with the pressure difference,the influence of the speed is approximately linearly increased,and the influence of the speed is more gentle than the influence of the pressure difference;among the five materials,the stress and strain of the graphite structure are very large.From the perspective of the deformation of the seal ring,when other requirements are met,it is recommended to use beryllium bronze as a material.(4)Based on the consideration of elasticity,a series of parameters such as the radius of the hemispherical bubble structure,the height of the bubble,the number of bubbles and the thickness of the floating ring are changed to adapt to the demand of the load.The research results show that with the increase of the bubble radius,the equivalent stress value of the flexible support structure is significantly reduced.When the bubble radius is set to 0.9mm～1.5mm,the stress and strain of the flexible support structure tends to be stable;when the bubble height is 0.2mm～0.45 mm,The stress and strain of the sealing ring is not obvious;as the thickness of the floating ring increases,the maximum equivalent stress and maximum deformation of the flexible support structure continue to decrease,and the value of the floating ring becomes stable when the value of the floating ring thickness is 0.6mm～1.0mm. |
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