FreeCASE - Free(dom) Computational AeroServoElasticity
Last update:
January 15. 2016 14:05:15

Oblique shock

In this section we present the numerical results of AeroFoam solver for a very simple 2D aerodynamic test problem, such as the reflection of an oblique shock.

Problem definition

  • Domain:
    • Rectangular channel of length L = 4.17 m and height h = 1 m 
  • Material:
    • Polytropic Ideal Gas (PIG)
    • Specific heat ratio gamma = 1.4
    • Gas thermodynamic constant R = 287.05 J/kgK
  • Initial conditions: 
    • Thermodynamic pressure Poo = 101325 Pa
    • Temperature Too = 288.15 K
    • Mach number Moo = 2.9
  • Boundary conditions:
    • SupersonicInlet boundary conditions on the inlet section (front and top walls)
    • ExtrapolatedOutlet boundary conditions on the outlet section
    • Slip boundary conditions on the bottom wall


Figure: Problem definition.

Space and time discretization

  • Space discretization:
    • Progressively refined meshes created with blockMesh
    • # of rectangular cells Nv = 400 - 1600 - 6400 - 25600
    • # of nodes Nn = 451 - 1701 - 6601 - 26001
  • Time discretization:
    • Total simulation time endTime = 0.01 s
    • Timestep deltaT = 4e-5 - 2e-5 - 1e-5 - 5e-6 s
    • Maximum Courant number maxCo =  1.95


Figure:
Computational grid.

Numerical results

  • Comparison with exact solution and with OpenFOAM built-in inviscid compressible solvers rhoSonicFoam, rhopSonicFoam and sonicFoam
  • Single iteration CPUtime = 8.16e-3 - 2.07 e-2 - 6.11e-2 - 2.22e-2 s on AMD64 3500+ desktop PC with AMD Athlon 64 2.2 GHz CPU, 1 Gbyte RAM, 512 Kbyte L2 cache


Figure:
Thermodynamic pressure P contours at t = 0.02.



Table: Comparison of the accuracy and efficiency performances of the evaluated solvers.



Figure:
Thermodynamic pressure P contours as a function of time t = 0 - 0.02.

Download

  • ObliqueShock.tar.gz test problem folder. Uncompress this archive in the OpenFOAM work folder and execute AeroFoam . ObliqueShock_AeroFoam from terminal to start the simulation. Download.



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