Research On Numerical Simulation Of N-S Equations For The Three-Dimensional Flow Field In Transonic Compressor Rotor

This dissertation has developed a numerical method of three-dimensionalNavier-Stokes Equations Solutions for flow field in Turbomachinery. It coveres fivechapters. Chapter I summarizes the development in the area of CFD for calculatingflow field in the turbomachinery, analyzing the influence of numerical scheme andthe mesh quality on accuracy and convergence. Chapter â…¡ formulates the samegoverning Equations for both stator in absolute frame and rotor in rotating frame. Onecan adopt the same numerical scheme for flow filed of stator and rotor. Governingequations are changed into curvilinear coordinate systems, and are simplified bymaking the thin-layer approximation. Chapter â…¢ presents the method to solve thethin-layer governing equations numerically. To integrate governing equations in time,implicit convective fluxes and explicit diffusive fluxes are used. Finite volumemethod is used to integrate equations in space, convective fluxes are evaluated usingRoe's flux difference splitting to form a higher-order TVD scheme, while diffusivefluxes are evaluated using central difference scheme. The flow field of both rotor inrotating frame and stator in absolute frame are steady, and grid motion are freezing.Consequently, local time stepping can be applied to accelerate solution convergence.The Newton's iterative method is used to convert the nonlinear algebraic equationsintegrated from the governing Equations into linear equations, and solutions areobtained by using symmetric Gauss-Seidel iterative method. Chapter â…£ firstlysimulates the flow field around the flat plate, to verify the validity of the modifiedtwo-layer Baldwin and Lomax algebraic turbulence model. Then the flow field forTurmo IIIc tandem cascade stator is calculated and analyzed. Finally, comparison isfinished between the calculated results and experiment data on French blade profileof ONERA to test the code reliability for tandem cascade stator. Chapter â…¤calculates the NASA Rotor67 to validate the code's reliability for rotor. Firstly, itsummarizes the test data and numerical calculations about transonic flow field in theNASA Rotor67 quoted from literatures. Then with simplified periodic H type meshes,flow field in the NASA Rotor67 without tip leakage flow is simulated, and results arecompared with experimental data in details. Using three kinds of different meshesseparately, ie:1) simplified periodic H type meshes, 2) periodic H type meshesperpendicular to wall, 3) non- periodic H type meshes, the flow field for NASARotor67 at operating point near peak efficiency is calculated and compared with eachother, in order to analyzing the influences of meshes on numerical accuracy. Lastly,flow field in the NASA Rotor67 with tip leakage flow are also calculated, andcompared with the result of Adamczyk. Chapter â…¥ is the summarization of thedissertation and prospect for the future work..