The Preliminary Study On Curve Expansion Wave In Two Dimensional Axisymmetric Flow Of Ideal Gas In Circular Thrust Bearing

With the developement of the micro engineering, precision machining, precision andultra precision processing industries, the research on gas bearing has been paid more andmore attention. Analysis on the flow state beyond the gas bearing has an importanttheoretical significance on the working characteristics of gas bearing. Supersonic flowwill come out expansion wave under the influence of internal structure of in gasbearing,and bearing force will be influenced by expansion wave.This essay usescharacteristic feature line coordinates method to analyze the status of the ideal gascurve expansion wave and wave flow state after within the divergent clearance thrust gasbearing disk.The conversion gas dynamics equations from the Descartes coordinate system to themethod of characteristic line coordinates, sorting out the Maher number of symmetricone-dimensional column flow in the parallel circular thrust by using characteristic linemethod under the characteristic feature line, Through the numerical solution is comparedwith theoretical solutions, verifies the correctness of the method solve supsonic in gasbearing.Base the physical model of the divergent clearance thrust gas bearing disk, using thecharacteristic line method to sort out the non characteristic initial value problem undercharacteristic line coordinates. Through the analysis of different boundary conditions, wefound that we can sort out the parameter of the expansion wave region when arc connectsbearing divergent at the turning point and gradually draws near to the turning point.Ultilization of the Fortran90programming calculation of the expansion wave isbased on the above method,the numerical calculation parameters of the characteristics ofgrid point was carried out analysis. The calculation results shows the shape of theexpansion wave in the symmetric two-dimensional gas column when it was interuptedby the turning of the convex wall and the airflow direction of the wave after. Thiscalculation method can be used for calculation of expansion wave of two-dimensionalradial flow without wave symmetry column flow.