Forward Facing Step
This test is transient, compressible, inviscid flow. The wind tunnel has 1 length unit wide and 3 length units long. The step is 0.2 length units high and is located 0.6 length units from the left-hand end of the tunnel. The tunnel is assumed to have an infinite width in the direction orthogonal to the plane of the computation (i.e., “slab symmetry” is assumed). So, we treat it as a two-dimensional problem. Initially the wind tunnel is filled with a gamma-law gas, with ϒ = 1.4, which everywhere has density 1.4, pressure 1.0, and velocity 3. Gas with this density, pressure, and velocity is continually fed in from the left-hand boundary.
References:
[1] “ANSY Fluid Dynamics verification Manual”, 2019 R3
[2] Woodward, P., Colella, P., "The Numerical Simulation of Two-Dimensional Fluid Flow with Strong Shocks", Journal of Computational Physics, Vol 54, pp. 115-173, 1984
*DUALCESE_MODEL
*DUALCESE_CONTROL_SOLVER
*DUALCESE_CONTROL_TIMESTEP
*DUALCESE_CONTROL_LIMITER
*DUALCESE_INCLUDE_MODEL
*DUALCESE_BOUNDARY_PRESCRIBED_SEGMENT_SET
*DUALCESE_BOUNDARY_NON_REFLECTIVE_SEGMENT_SET
*DUALCESE_BOUNDARY_REFLECTIVE_SEGMENT_SET
*DUALCESE_BOUNDARY_SOLID_WALL_SEGMENT_SET
*DUALCESE_INITIAL
*DUALCESE_PART
*DUALCESE_EOS_IDEAL_GAS
*DUALCESE_D3PLOT
*CONTROL_TERMINATION
*DATABASE_BINARY_D3PLOT
*DATABASE_BINARY_D3DUMP
*KEYWORD
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*DUALCESE_CONTROL_SOLVER
$ ieqns igeom iframeref
Euler 2D fixed
*DUALCESE_CONTROL_TIMESTEP
$ iddt cfl dtint
2 0.5 0.0001
*DUALCESE_CONTROL_LIMITER
$ idlmt alfa beta epsr
0 2.0 1. 0.001
$
*DUALCESE_INCLUDE_MODEL
fluid_m1q.k
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$ Setup the boundary conditions for fluid
$ Prescribed inlet BC (left)
*DUALCESE_BOUNDARY_PRESCRIBED_SEGMENT_SET
$ ssid
1
$ lcid_u lcid_v lcid_w lcid_d lcid_p lcid_t
-1
$ sf_u sf_v sf_w sf_d sf_p sf_t
3.0 0.0 0.0 1.4 1.0
$ Outflow BC
*DUALCESE_BOUNDARY_NON_REFLECTIVE_SEGMENT_SET
$ ssid
2
$ Solid BC_3 (tunnel wall)
*DUALCESE_BOUNDARY_SOLID_WALL_SEGMENT_SET
$ ssid
3
*DUALCESE_BOUNDARY_REFLECTIVE_SEGMENT_SET
$ ssid
5
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$ Setup the initial conditions for fluid
*DUALCESE_INITIAL
$ uic vic wic rhoic pic tic hic
3.0 0.0 0.0 1.4 1.0
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$ Setup fluid properties
*DUALCESE_PART
$ pid mid eosid
1 5
*DUALCESE_EOS_IDEAL_GAS
$ eosid cv cp
5 0.198413 0.277778
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$ Handle output of flow variables
*DUALCESE_D3PLOT
density
pressure
velocity
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*END