Temperature Field Analysis And Dynamic Performance Research Of Inlaid Gas Film Floating Ring Seal

The inlaid gas film floating ring seal has many advantages,such as simple form,reliable strength and stable sealing performance,so it is widely used in engine bearing cavity.However,when the design or operation is not appropriate,under high temperature,high speed,high pressure or disturbance conditions,the floating ring seal is prone to high temperature failure,seal performance instability,and even collision with the spindle.In this paper,the temperature field,dynamic characteristics and sealing performance of the floating ring sealing system under disturbed condition were studied systematically and deeply.The finite element model of temperature field of floating ring seal under accurate temperature boundary condition was established by Fluent software.The temperature distribution of gap gas film,embedded floating ring and runway were obtained,and the influence of operating conditions on the temperature field of the seal was analyzed.The results show that the higher the inlet temperature and speed,the larger the maximum temperature and temperature span of the floating ring seal.With the increase of speed,the maximum temperature gradually moves away from the runway entrance,which has a delay effect.Properly increasing the gap can significantly improve the temperature field of gas film and floating ring and make it more uniform.By cooling the runway,the temperature distribution of the film and runway can also be more uniform.Based on CFD quasi steady state method,a model of whirling rotor air film floating ring seal was established,and a method to study the dynamic characteristics of air film floating ring seal was proposed.The variation of dynamic characteristic parameters of gas film floating ring seal under different sealing parameters was obtained.The results show that increasing the throttling length of the floating ring and reducing the seal clearance can significantly improve the dynamic stability of the seal,and promote the gas film floating ring seal system to achieve a good running state of buffering,anti-interference and continuous operation.The transient modeling method of CFD gas film floating ring seal with dynamic boundary conditions was used to simulate the transient leakage and buoyancy of the floating ring seal with sinusoidal pressure and temperature disturbance.By changing different structural parameters,it was found that the transient seal stability of floating ring is negatively correlated with the seal clearance.In the actual design,the throttle length should be increased appropriately to ensure that the gas film floating ring seal can maintain good sealing performance stability under poor stability conditions.The temperature characteristics and dynamic stability tests were carried out,and the relevant laws of the temperature change and dynamic characteristics of the floating ring seal under different working conditions were obtained.The test results were basically consistent with the simulation results,which verified the correctness and reliability of the numerical analysis.The research on the temperature field,dynamic characteristics and dynamic stability of the inlaid gas film floating ring seal can provide a new research idea for the performance improvement,stability analysis and optimization design of the floating ring seal.It also provides technical support for its further application and promotion.