The Study Of Padded Finger Seal With Equivalent Dynamic Model

High-speed dynamic sealing devices are widely used in aero-engine. vehicle turbocharger bearing cavity, the high speed railway bearing cavity?the ground gas turbine and the large TRT generator set balance plate seal, the padded finger seal is a kind of new seal form of non-contacting finger based on the contacting finger seal, which appropriate for the situation which condition is more severe and require higher working life, which appropriate for the situation with higher speed and higher working life. The fluid pressure tip seals have been developed over the years has been matured, however, due to its sealing structure and the complexity of operating conditions, especially under super high speed condition, research on the bearing capacity and leakage characteristics of the gas membrane is still lacking, there is a gap in the research that has been put in place. Under high speed conditions, the performance of the fluid pressure tip is dependent on the stability of the gas film in the dynamic condition, a large number of studies have shown the stability of the gas membrane and the design, of the tip of the fingertip that is sealed with a fluid pressure tip, especially the line structure has important relations. The upper concave type line is a new type of line in recent years, the shape of its special finger tips gives it special mechanical properties, the formation of a stable dynamic gas film with fluid dynamic pressure under superhigh speed conditions has good potential.Therefore, a concave shape-curve mass-spring-damp equivalent dynamics model set up in this paper intends to analyze from the mechanical. The analysis establishes the equations between the dynamic parameters, structure parameters as well as working parameters in the system, at the same tme. On the basis of the previous works, the analysis of dynamics performance and the calculation of leakage can be done, study of the dynamic performance of the fluid pressure tip seals and the method of calculating the leakage quantity of the liquid pressure tip is constructed. In this paper, the dynamic characteristics of the upper concave and traditional linear fluid pressure tip seals are studied. In this study, the equivalent stiffness and equivalent mass of the finger stick are worked out as stiffness of the springs and mass of the mass by using the commercial finite element software package of ANSYS; equivalent friction force of the padded finger seal system can be obtained, which based on the finite element contact simulation analysis, with the aid of the science computation software MATLAB. Then equivalent stiffness and equivalent damp of the fluid film can be obtained by the CFX software.The third step is to get the function between the derived equivalent parameter and the corresponding construction-condition parameter by using SPSS data processing software. The last step, get the equations of dynamic response and leakage by solving the equivalent differential equation.The results show that the dynamic performance calculation method can be used to reflect the dynamic characteristics of the fluid pressure fingertips and the comprehensive performance advantage of the upper concave line under the hypervelocity condition is also proved at the same time. The proposed method and the preliminary results of the study are to promote the research on the sealing of fluid pressure fingertips, advance the application of the project is of great significance.