An unstructured Reynolds-averaged Navier-Stokes flow solver using the finite volume method is studied. The spatial discretisation is based on the Osher approximate Riemann solvers. A two-equation turbulence model (k-...An unstructured Reynolds-averaged Navier-Stokes flow solver using the finite volume method is studied. The spatial discretisation is based on the Osher approximate Riemann solvers. A two-equation turbulence model (k-ω model) is also developed for hybrid grids to compute the turbulence flow. The turbulence flow past NACA0012 airfoil and the double ellipsolids are computed, and the numerical results show that the above methods are very efficient.展开更多
We give the explicit formulas of the minimizers of the anisotropic Rudin-Osher-Fatemi models Eφ1(U)=∫Ωφ°(Du)Dx+λ∫|u-f|dx,u∈BV(Ω) Eφ2(U)=∫Ωφ°(Du)Dx+λ∫(u-f)2dx,u∈BV(Ω),where ...We give the explicit formulas of the minimizers of the anisotropic Rudin-Osher-Fatemi models Eφ1(U)=∫Ωφ°(Du)Dx+λ∫|u-f|dx,u∈BV(Ω) Eφ2(U)=∫Ωφ°(Du)Dx+λ∫(u-f)2dx,u∈BV(Ω),where Ω R2 is a domain, φ° is an anisotropic norm on R2, and f is a solution of the anisotropie 1-Laplaeian equations.展开更多
The computational fluid dynamics (CFD) method is used to investigate the aerodynamic characteristics of the seat/occupant with windblast protection devices. The upwind Osher scheme is used for the spatial discretisa...The computational fluid dynamics (CFD) method is used to investigate the aerodynamic characteristics of the seat/occupant with windblast protection devices. The upwind Osher scheme is used for the spatial discretisation. The detached-eddy simulation (DES) based on the Spalart-Allmaras one-equation turbulence model is ap- plied to the detached viscous flow simulation behind the seat/occupant, with Mach numbers 0.6 and 1.2 at attack angles between --10 and 30°, and at two sideslip angles of 0 and 15°, respectively. The aerodynamic characteristics of seat/occupants with and without windblast protection devices are calculated in cases of the freestream Mach numbers 0. 8 and 1.6, attack angles from 5 to 30°, and three sideslip angles of 0, --20 and --50°, respectively. Results show that simulation results agree well with experimental data. And the occupant is efficiently protected by windblast protection devices.展开更多
文摘An unstructured Reynolds-averaged Navier-Stokes flow solver using the finite volume method is studied. The spatial discretisation is based on the Osher approximate Riemann solvers. A two-equation turbulence model (k-ω model) is also developed for hybrid grids to compute the turbulence flow. The turbulence flow past NACA0012 airfoil and the double ellipsolids are computed, and the numerical results show that the above methods are very efficient.
基金Acknowledgements The authors thank the referees for careful reading of the paper and useful suggestions which improve the presentation. This work was supported by the National Natural Science Foundation of China (Grant Nos. 11271025, 11371038, 11431001).
文摘We give the explicit formulas of the minimizers of the anisotropic Rudin-Osher-Fatemi models Eφ1(U)=∫Ωφ°(Du)Dx+λ∫|u-f|dx,u∈BV(Ω) Eφ2(U)=∫Ωφ°(Du)Dx+λ∫(u-f)2dx,u∈BV(Ω),where Ω R2 is a domain, φ° is an anisotropic norm on R2, and f is a solution of the anisotropie 1-Laplaeian equations.
基金Supported by the Aeronautical Science Foundation of China(2008ZC52039)~~
文摘The computational fluid dynamics (CFD) method is used to investigate the aerodynamic characteristics of the seat/occupant with windblast protection devices. The upwind Osher scheme is used for the spatial discretisation. The detached-eddy simulation (DES) based on the Spalart-Allmaras one-equation turbulence model is ap- plied to the detached viscous flow simulation behind the seat/occupant, with Mach numbers 0.6 and 1.2 at attack angles between --10 and 30°, and at two sideslip angles of 0 and 15°, respectively. The aerodynamic characteristics of seat/occupants with and without windblast protection devices are calculated in cases of the freestream Mach numbers 0. 8 and 1.6, attack angles from 5 to 30°, and three sideslip angles of 0, --20 and --50°, respectively. Results show that simulation results agree well with experimental data. And the occupant is efficiently protected by windblast protection devices.