*HEADING
EC3AAFAW: Nonreflective end-condition with large drag with AC3D10
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
51,91
101,141
201,241
501,541
601,641
1001,1041
1051,1091
1101,1141
*NSET,NSET=LOAD1
1,101,1001,1101
*NSET,NSET=LOAD2
51,501,601,1051
*NSET,NSET=QA_TEST,GENERATE
1,41,2
*ELEMENT,TYPE=AC3D10,ELSET=EALL
    1,    1,    3,  103, 1001,
          2,53,52,501,502,202,
    2,    3,  103, 1001, 1003,
          53,202,502,503,203,1002,
    3,  103, 1001, 1003, 1103,
        202,1002,203,603,1052,1053,
    4,    1,  103,  101, 1001,
        52,102,51,501,202,201,
    5,  103,  101, 1001, 1103,
        102,201,202,603,602,1052,
    6,  101, 1001, 1103, 1101,
        201,1052,602,601,1051,1102,
*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
*ELSET,ELSET=NONREF
120,118
*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.
**  Distribute (1/6,-1/6, 1) to each (corner,midside,center)
**  node, respectively:
**
*CLOAD,LOAD CASE=2, AMP=OMEGA
LOAD1,8,0.6666666666E-4
LOAD2,8,-.6666666666E-4
201,8,4.0E-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,LOAD CASE=2, AMP=OMEGA
 LOAD1,8,0.6666666666E-4
 LOAD2,8,-.6666666666E-4
 201,8,4.0E-4
*ENERGYPRINT
*NODE PRINT, NSET=QA_TEST
COORD,POR,PPOR
*OUTPUT,FIELD
*NODE OUTPUT,NSET=QA_TEST
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,Frequency=0
*END STEP
**
**
*STEP
*STEADY STATE DYNAMIC
100,1000,20
***IMPEDANCE
**116,I2
**117,I4
*CLOAD,LOAD CASE=2, AMP=OMEGA
LOAD1,8,0.6666666666E-4
LOAD2,8,-.6666666666E-4
201,8,4.0E-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,LOAD CASE=2, AMP=OMEGA
LOAD1,8,0.6666666666E-4
LOAD2,8,-.6666666666E-4
201,8,4.0E-4
*OUTPUT,FIELD
*NODE OUTPUT
POR,
*OUTPUT,HISTORY
*NODE OUTPUT,NSET=QA_TEST
POR,
*END STEP