A PLU-SGS method based on a time-derivative preconditioning algorithm and LU-SGS method is developed in order to calculate the Navier-Stokes equations at all speeds. The equations were discretized using A USMPW scheme...A PLU-SGS method based on a time-derivative preconditioning algorithm and LU-SGS method is developed in order to calculate the Navier-Stokes equations at all speeds. The equations were discretized using A USMPW scheme in conjunction with the third-order MUSCL scheme with Van Leer limiter. The present method was applied to solve the multidimensional compressible Navier-Stokes equations in curvilinear coordinates. Characteristic boundary conditions based on the eigensystem of the preconditioned equations were employed. In order to examine the performance of present method, driven-cavity flow at various Reynolds numbers and viscous flow through a convergent-divergent nozzle at supersonic were selected to rest this method. The computed results were compared with the experimental data or the other numerical results available in literature and good agreements between them are obtained. The results show that the present method is accurate, self-adaptive and stable for a wide range of flow conditions from low speed to supersonic flows.展开更多
A time marching algorithms, which is used to solve incompressible internal flow fields in turbomachinery, has beendeveloped. By using Chorin’s method of artificial compressibility, the governing equations are transfo...A time marching algorithms, which is used to solve incompressible internal flow fields in turbomachinery, has beendeveloped. By using Chorin’s method of artificial compressibility, the governing equations are transformed fromelliptic type into hyperbolic form in order to extend the time marching technique to very low Mach number flows.Viscous effects can be predicted by using the distributed body force method and Baldwin-Lomax eddy viscosityturbulence model. Some accelerating convergence techniques such as multi-grid and local time step method areemployed. The applicahon to a flow field within a low-solidity rocket pump inducer is presented and discussed.展开更多
Afast and accurate three dimensional (3 D) viscous code for calculating flows in turbomachinery has been established.In this code, H meshes are adopted to build the discrete equations, and the conservation equatio...Afast and accurate three dimensional (3 D) viscous code for calculating flows in turbomachinery has been established.In this code, H meshes are adopted to build the discrete equations, and the conservation equationsare solved on grid nodes atthe corners of cuboid elements.In orderto accelerate convergence,local time stepping,residualsmoothing and multigrid method are also applied,andthe viscous effects are approximatedby a very simple mixing length model.For verification ofthe accuracy and applicability ofthe method,transonicflowsthrough compressor cascades of NASArotor 37 and flows through a turbine stator of NASAhave been calculated.The good agreementbetween experimentalresults and design data has demonstratedthereliability and applicability ofthe present method,which can be usedforsimulatingthe complex 3 Dviscousflow phenomenonin turbomachinery.展开更多
文摘A PLU-SGS method based on a time-derivative preconditioning algorithm and LU-SGS method is developed in order to calculate the Navier-Stokes equations at all speeds. The equations were discretized using A USMPW scheme in conjunction with the third-order MUSCL scheme with Van Leer limiter. The present method was applied to solve the multidimensional compressible Navier-Stokes equations in curvilinear coordinates. Characteristic boundary conditions based on the eigensystem of the preconditioned equations were employed. In order to examine the performance of present method, driven-cavity flow at various Reynolds numbers and viscous flow through a convergent-divergent nozzle at supersonic were selected to rest this method. The computed results were compared with the experimental data or the other numerical results available in literature and good agreements between them are obtained. The results show that the present method is accurate, self-adaptive and stable for a wide range of flow conditions from low speed to supersonic flows.
文摘A time marching algorithms, which is used to solve incompressible internal flow fields in turbomachinery, has beendeveloped. By using Chorin’s method of artificial compressibility, the governing equations are transformed fromelliptic type into hyperbolic form in order to extend the time marching technique to very low Mach number flows.Viscous effects can be predicted by using the distributed body force method and Baldwin-Lomax eddy viscosityturbulence model. Some accelerating convergence techniques such as multi-grid and local time step method areemployed. The applicahon to a flow field within a low-solidity rocket pump inducer is presented and discussed.
文摘Afast and accurate three dimensional (3 D) viscous code for calculating flows in turbomachinery has been established.In this code, H meshes are adopted to build the discrete equations, and the conservation equationsare solved on grid nodes atthe corners of cuboid elements.In orderto accelerate convergence,local time stepping,residualsmoothing and multigrid method are also applied,andthe viscous effects are approximatedby a very simple mixing length model.For verification ofthe accuracy and applicability ofthe method,transonicflowsthrough compressor cascades of NASArotor 37 and flows through a turbine stator of NASAhave been calculated.The good agreementbetween experimentalresults and design data has demonstratedthereliability and applicability ofthe present method,which can be usedforsimulatingthe complex 3 Dviscousflow phenomenonin turbomachinery.
