*HEADING
EC3FAFAW: Nonreflective end-condition with large drag with AC3D15
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
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=AC3D15,ELSET=EALL
    1,    1, 1001,    3,  101, 1101,  103,
          501,  502,    2,  601, 602,  102,
           51, 1051,   53,
    2,    3, 1001, 1003,  103, 1101, 1103,
          502, 1002,  503, 602, 1102,  603,
           53, 1051, 1053,
*ELGEN,ELSET=EALL
1,20,2,2
2,20,2,2
*ELSET,ELSET=NONREF
40,
*surface,NAME=NRS
NONREF,S5
*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
 NONREF,I5
**
** Conditions at x=0 : Define the source inward accel
**  to be  a =  omega i, so v (inward) = 1.
**
**  Area of face=A. Total inward VOLUME acceleration
**  is A*a. This should be distributed in the ratio
**  (-1/12,1/3) to the (corner,midside) nodes, 
**  respectively:
*CLOAD,LOAD CASE=2, AMP=OMEGA
LOAD1, 8, -.33333333333E-4
LOAD2, 8, 1.33333333333E-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, -.33333333333E-4
LOAD2, 8, 1.33333333333E-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
** NONREF,I5
*CLOAD,LOAD CASE=2, AMP=OMEGA
LOAD1, 8, -.33333333333E-4
LOAD2, 8, 1.33333333333E-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, -.33333333333E-4
LOAD2, 8, 1.33333333333E-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