RESEARCH ON IMPLICIT TIME-MARCHING METHODS FOR TRANSONIC FLOWS
| Project/Area Number |
61460098
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Fluid engineering
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
HISAAKI DAIGUJI FACULTY FO ENGINEERING, TOHOKU UNIVERSITY, 工学部, 教授 (70005239)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1987: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1986: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Computational Fluid Dynamics / Compressible Euler Equations / Compressible Navier-Stokes Equations / Incompressible Navier-Stokes Equations / Implicit Time-Marching Finite-Difference Scheme / Curvilinear Coodinate Grid / Transonic Flow / 三次元翼列流れ / 流体力学 / 数値解析 / オイラー方程式 / ナビエ・ストークス方程式 / 差分法 / 陰的時間進行法 / ターボ機械の翼列流れ |
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| Research Abstract |
The purposes of this research are to propose highly accurate and efficient algorithms in curvilinear coordinates for analysing shocked transonic flows through a cascade, nozzle and diffuser of compressors and turbines, and to complete their programs. The writher had proposed an implicit time-marching finite-difference scheme for the 2-D compressible Euler equations, before the beginning of this research. The distinctive features of the method are to make use of the momentum equations of contravariant velocities, and to be able to treat the slip boundary condition on the solid wall accurately and simply. The main results of this research are as follows.
1. Explicit part computation. The originally used upstream-difference schemes containing the fourth-order artifitial dissipation team were replaced by the Chakravarthy-Osher TVD scheme, in order to capture clearer shock waves.
2. Vectorization ratio by using of supercomputer. The ratios larger than 99% ware attained even in the implicit part computation.
3. Extension to 3-D Euler CODE. Programs for computing the turbine nozzle and compressor rotor flows were developed. The use of the momentum equations of contravariant velocities makes the treatment of periodic boundary condition very easy.
4. Development of NS(Navier-Stokes) CODE. NS CODEs were made by taking account of diffusion terms in Euler CODE. In the calculation of trubulent flow, the twoequation k- model was used together with the law of the wall. Some computed results of 2-D and 3-D transonic cascade flows were obtained.
5. Incompressible NS CODE. Some schemes in curvilinear coordinate grids were derived from the time-marching MAC scheme, and compared each other. It was found that a scjeme used the momentum equations of contravariant velocities is the most excellent one.
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Report
(2 results)
Research Products
(27 results)
