*HEADING
EC34AFAW: Nonreflective end-condition with large drag with AC3D4
Compare IMPEDANCE WITH SIMPEDANCE, and STEADY STATE DYNAMICS, DIRECT
with SUBSPACE PROJECTION.
********************
*RESTART,WRITE
********************
**
**   Mesh Generation
**
*NODE, Nset=ODB_NSET
1,    0, 0
41,  .5, 0
51,   0, 1.e-2
91,  .5, 1.e-2
101,  0, 2.e-2
141, .5, 2.e-2
201,  0, 1.e-2,1.e-2
241, .5, 1.e-2,1.e-2
501,  0,  0, 1.e-2
541, .5,  0, 1.e-2
601,  0, 2.e-2, 1.e-2
641, .5, 2.e-2, 1.e-2
1001, 0,  0, 2.e-2
1041,.5,  0, 2.e-2
1051, 0, 1.e-2, 2.e-2
1091,.5, 1.e-2, 2.e-2
1101, 0, 2.e-2, 2.e-2
1141,.5, 2.e-2, 2.e-2
*NGEN,NSET=NALL
1,41
101,141
1001,1041
1101,1141
*NSET,NSET=LOAD
1,101, 1001,1101
*NSET,NSET=QA_TEST,GENERATE
1,41
*ELEMENT,TYPE=AC3D4,ELSET=EALL
    1,    1,    3,  103, 1001
    2,    3,  103, 1001, 1003
    3,  103, 1001, 1003, 1103
    4,    1,  103,  101, 1001
    5,  103,  101, 1001, 1103
    6,  101, 1001, 1103, 1101
*ELGEN,ELSET=EALL
1,20,2,6
2,20,2,6
3,20,2,6
4,20,2,6
5,20,2,6
6,20,2,6
*surface,NAME=NRS
116,S2
117,S4
**  Acoustic Element Properties
**
*SOLID SECTION,MATERIAL=ABSORB,ELSET=EALL
**
*MATERIAL,NAME=ABSORB
*DENSITY
 1.21,
*ACOUSTIC MEDIUM,BULK MODULUS
 0.1424E6,
*ACOUSTIC MEDIUM,VOLUMETRIC DRAG
1400.,
*AMPLITUDE,NAME=OMEGA
0.,0., 1E6,6.2831853E6
************************************************
**       ** ANALYTIC SOLUTION  **
**
**  at freq=100,
**  Impedance: Z = root( K_f (rho  - i r/omega))
**               = 516.411 -307.208 i
**  Propagation constant
**             b = i (omega/K_f) Z
**               = 1.35551 + 2.27859 i
**
**  Solution: with nonreflective end,
**  Complex pressure
**             p(x) = Z v(0) exp( - b x)
**  i.e. |p(x)| = |Z v(0)| exp ( - Re(b) x)
**              = 600.8805  exp ( -1.35551 x)
**
**       Arg(p) = Arg(Z) - Im(b) x
**       ppor   = -30.74799 - 130.5534 x
**
************************************************
*STEP
*STEADY STATE DYNAMIC,DIRECT
100,
*IMPEDANCE
 116,I2
 117,I4
**
** Conditions at x=0 : Define the source inward accel
**  to be  a =  omega i, so v (inward) = 1.
**  Area of face=4e-4. Total inward VOLUME acceleration
**  is 4e-4*a.
**  Prescribe unit _particle_ acceleration a0 inwards;
**  _volume_ acceleration ("force" for acoustics) is a0*cross-sec.
** 1/4 of this should be distributed to each
**  of the corner nodes:
*CLOAD,IMAGINARY, AMP=OMEGA
LOAD, 8, 1.e-4
*ENERGYPRINT
*NODE PRINT, NSET=QA_TEST
COORD,POR,PPOR
*OUTPUT,FIELD
*NODE OUTPUT
POR,
*ELEMENTOUTPUT
ENER,ELEN,ELEDEN
*OUTPUT,HISTORY
*NODE OUTPUT,NSET=QA_TEST
POR,
*ENERGYOUTPUT
ALLQB,ALLWK,ALLVD,ALLSE,ALLKE
*END STEP
**
**
*STEP
*STEADY STATE DYNAMIC,DIRECT
100,
*SIMPEDANCE
NRS,
*CLOAD,IMAGINARY, AMP=OMEGA
LOAD, 8, 1.e-4
*ENERGYPRINT
*NODE PRINT, NSET=QA_TEST
COORD,POR,PPOR
*OUTPUT,FIELD
*NODE OUTPUT
POR,
*ELEMENTOUTPUT
ENER,ELEN,ELEDEN
*OUTPUT,HISTORY
*NODE OUTPUT,NSET=QA_TEST
POR,
*ENERGYOUTPUT
ALLQB,ALLWK,ALLVD,ALLSE,ALLKE
*END STEP
**
**
*STEP
*FREQUENCY,EIGENSOLVER=AMS
4,,2000.,10.0,4.0,3.0
*OUTPUT,FIELD,FREQUENCY=0
*NODE PRINT,F=0
*EL PRINT,F=0
*OUTPUT,HISTORY
*ENERGYOUTPUT
ALLSE,ALLKE
*END STEP
**
**
*STEP
*STEADY STATE DYNAMIC
100,1000,20
***IMPEDANCE
** 116,I2
** 117,I4
*CLOAD,IMAGINARY, AMP=OMEGA
LOAD, 8, 1.e-4
*ENERGYPRINT
*OUTPUT,FIELD
*NODE OUTPUT
POR,
*ELEMENTOUTPUT
ENER,ELEN,ELEDEN
*OUTPUT,HISTORY
*ENERGYOUTPUT
ALLQB,ALLWK,ALLVD,ALLSE,ALLKE
*END STEP
**
*STEP
*STEADY STATE DYNAMIC
100,
***SIMPEDANCE
**NRS,
*CLOAD,IMAGINARY, AMP=OMEGA
LOAD, 8, 1.e-4
*ENERGYPRINT
*OUTPUT,FIELD
*NODE OUTPUT
POR,
*ELEMENTOUTPUT
ENER,ELEN,ELEDEN
*OUTPUT,HISTORY
*NODE OUTPUT,NSET=QA_TEST
POR,
*ENERGYOUTPUT
ALLQB,ALLWK,ALLVD,ALLSE,ALLKE
*END STEP