Research Of Thermal Fluid Brush Seal Used In Aircraft Rudder Shaft

As a kind of the flexible contact seal with low leakage rate, low wear rate, long life, brush seal has been applied in the field of military and civilian large impeller machine. So far, the studies of brush seal are mainly on the single-track and high speed condition. Based on the aircraft rudder shaft sealing with high temperature, thermal insulation, intermittent swing and differential pressure direction specific condition, a new kind of brush seal has been presented and researched for its manufacture and sealing propertiesTwo-dimensional axisymmetric rotational leakage and heat transfer model of thermal fluid brush seal used in aircraft rudder shaft was established by taking its internal brush area as a Non-Darcian porous medium. The flow field, leakage rate and heat flow of the model were simulated and calculated. Analyze the influence of different structural parameters, operating conditions and installation parameters on the flow and heat transfer properties and get the optimal scope of each parameter. By uniform design method of multivariate linear regression, the influences structural parameters on the sealing performance was analyzed. And get influence on the leakage rate from heavy to light are porosity, backplane gap, wire brush thickness and front plate gap. In view of non-uniform inter-stage pressure problems of multistage brush seal, put forward a method that can alter the resistance to achieve partial pressure evenly by changing the structural parameters of brush seal.Analyze the brush seal contact force due to interference installation and the differential pressure by the theory of linear cantilever beam and simply supported beam, and deduce radial stiffness and axial stiffness of the brush. Introduction of the concept about equivalent sealing pressure and put forward judgment criterion about brush end contact. Based on theory seal life and safety factor, a method to predicate the brush seal life was presented. And the theory seal life was deduced by adhesive wear theory between brush and surface of shaft, meanwhile, the safety factor was calculated by fuzzy comprehensive evaluation method.Develop a running back and forth brush seal test device and compare the results of experiment and theoretical researches, prove that theoretical researches of this paper is correct. The researches of the sealing performance and manufacturing have an important significance on brush seal design and improvement, application development and low processing cost.