*HEADING
This input deck tests the behavior of pneumatic and hydraulic fluids in a fluid
 cavity.
Behavior: Effect of change of cavity pressure, temperature and volume on the 
fluid response.

The following 5 cavities have been defined:
PNEUMATIC FLUIDS:
        CAVITY I        : Isothermal cavity with one gas
        CAVITY II       : Isothermal cavity with two gases (Mixture)      
        CAVITY III      : Adiabatic cavity with one gas
        CAVITY IV       : Adiabatic cavity with two gases (Mixture)
HYDRAULIC FLUIDS:
        CAVITY V        : Cavity with hydraulic fluid 
Temperature dependence of fluid properties has been considered in all the 
cavities. 
e.g: In case of pneumatic fluids heat capcity is considered to be temeprature 
dependent and in case of hydraulic fluids, temperature dependence of density 
and bulk modulus has been taken into account.

System of units: SI

                       ANALYTICAL RESULTS SUMMARY

|-----------------------------------------------------------------------------|
|Var.  | t |  CAV I   |  CAV II   |  CAV III   |   CAV IV    |     CAV V      |
|-----------------------------------------------------------------------------|
CVOL     0    0.2250   
         1    0.2250   
         2    0.2250   CVOL(t) will be the same for all the cavities
         3    0.1625   
         4    0.1375   
------------------------------------------------------------------------------
CMASS    0    0.8003    0.7902      0.4959       0.4896           225.00     
         1    1.3339    1.3170      0.8265       0.8160           251.47     
                  CMASS will remain the same after t=1 for all the cavities  
------------------------------------------------------------------------------
CTEMP    0    20        20          200          200              20     
(deg C)  1    20        20          200          200              20     
         2    200       200         200          200              200    
         3    200       200         262.6596     262.8337         200    
         4    200       200         297.5439     297.8122         200    
**NOTE: CTEMP variable is not available for output request for isothermal 
        cavities and cavities with hydraulic fluids 
------------------------------------------------------------------------------
PCAV     0    200000    200000      200000       200000           0      
(gauge   1    400000    400000      400000       400000           400000
for pneu 2    706999    706999      400000       400000           234282 
fluids)  3    1017384   1017384     683988.53    684243.25        731359 
         4    1220544   1220544     886853.34    887317.28        930190 
------------------------------------------------------------------------------
After (0.10/0.12) of the total step time of step 4, minimum volume specified 
in the fluid cavity defintion will be used to compute fluid pressure.     
------------------------------------------------------------------------------
**  
*PHYSICAL CONSTANTS, ABSOLUTE ZERO=-273.16, UNIVERSAL GAS CONSTANT=8.314
**
**=============================
**      CAVITY I
**=============================
*SYSTEM
0, 0, 0
*NODE, NSET=ISO_1GAS
11, 0., 0., 0.
12, 0.5, 0., 0.
13, 0.5, 0.5, 0.
14, 0., 0.5, 0.
15, 0., 0., 0.5
16, 0.5, 0., 0.5
17, 0.5, 0.5, 0.5
18, 0., 0.5, 0.5
**
** Cavity Ref. node 
**
*NODE, NSET=ISO_1GAS_REF
199, 0.25, 0.25, 0.25
**
** Elements defined such that all normals point inward
**
*ELEMENT, TYPE=SFM3D4R, ELSET=ISO_1GAS
11, 12, 13, 14, 11
12, 18, 17, 16, 15
13, 15, 16, 12, 11
14, 16, 17, 13, 12
15, 17, 18, 14, 13
16, 18, 15, 11, 14
*SURFACE, NAME=ISO_1GAS_SURF, TYPE=ELEMENT
ISO_1GAS, SPOS
**
**Fluid cavity definition
**
*FLUID CAVITY, NAME=ISO_1GAS_CAV, BEHAVIOR=AIR, REF NODE=ISO_1GAS_REF, 
SURFACE=ISO_1GAS_SURF, AMBIENT PRESSURE=1.0E5, ADDED VOLUME=0.10, 
MINIMUM VOLUME=0.1375

**=============================
**      CAVITY II
**=============================
*SYSTEM
2, 0, 0
*NODE, NSET=ISO_MIX
21, 0., 0., 0.
22, 0.5, 0., 0.
23, 0.5, 0.5, 0.
24, 0., 0.5, 0.
25, 0., 0., 0.5
26, 0.5, 0., 0.5
27, 0.5, 0.5, 0.5
28, 0., 0.5, 0.5
**
** Cavity Ref. node 
**
*NODE, NSET=ISO_MIX_REF
299, 0.25, 0.25, 0.25
**
** Elements defined such that all normals point inward
**
*ELEMENT, TYPE=SFM3D4R, ELSET=ISO_MIX
21, 22, 23, 24, 21
22, 28, 27, 26, 25
23, 25, 26, 22, 21
24, 26, 27, 23, 22
25, 27, 28, 24, 23
26, 28, 25, 21, 24
*SURFACE, NAME=ISO_MIX_SURF, TYPE=ELEMENT
ISO_MIX, SPOS
**
**Fluid cavity definition
**
*FLUID CAVITY, NAME=ISO_MIX_CAV, MIXTURE, REF NODE=ISO_MIX_REF, 
SURFACE=ISO_MIX_SURF, AMBIENT PRESSURE=1.0E5, ADDED VOLUME=0.10, 
MINIMUM VOLUME=0.1375

AIR, 0.6
NITROGEN, 0.4
**=============================
**      CAVITY III
**=============================
*SYSTEM
4, 0, 0
*NODE, NSET=ADB_1GAS
31, 0., 0., 0.
32, 0.5, 0., 0.
33, 0.5, 0.5, 0.
34, 0., 0.5, 0.
35, 0., 0., 0.5
36, 0.5, 0., 0.5
37, 0.5, 0.5, 0.5
38, 0., 0.5, 0.5
**
** Cavity Ref. node 
**
*NODE, NSET=ADB_1GAS_REF
399, 0.25, 0.25, 0.25
**
** Elements defined such that all normals point inward
**
*ELEMENT, TYPE=SFM3D4R, ELSET=ADB_1GAS
31, 32, 33, 34, 31
32, 38, 37, 36, 35
33, 35, 36, 32, 31
34, 36, 37, 33, 32
35, 37, 38, 34, 33
36, 38, 35, 31, 34
*SURFACE, NAME=ADB_1GAS_SURF, TYPE=ELEMENT
ADB_1GAS, SPOS
**
**Fluid cavity definition
**
*FLUID CAVITY, NAME=ADB_1GAS_CAV, BEHAVIOR=AIR, REF NODE=ADB_1GAS_REF, 
SURFACE=ADB_1GAS_SURF, AMBIENT PRESSURE=1.0E5, ADDED VOLUME=0.10, 
MINIMUM VOLUME=0.1375, ADIABATIC

**=============================
**      CAVITY IV
**=============================
*SYSTEM
6, 0, 0
*NODE, NSET=ADB_MIX
41, 0., 0., 0.
42, 0.5, 0., 0.
43, 0.5, 0.5, 0.
44, 0., 0.5, 0.
45, 0., 0., 0.5
46, 0.5, 0., 0.5
47, 0.5, 0.5, 0.5
48, 0., 0.5, 0.5
**
** Cavity Ref. node 
**
*NODE, NSET=ADB_MIX_REF
499, 0.25, 0.25, 0.25
**
** Elements defined such that all normals point inward
**
*ELEMENT, TYPE=SFM3D4R, ELSET=ADB_MIX
41, 42, 43, 44, 41
42, 48, 47, 46, 45
43, 45, 46, 42, 41
44, 46, 47, 43, 42
45, 47, 48, 44, 43
46, 48, 45, 41, 44
*SURFACE, NAME=ADB_MIX_SURF, TYPE=ELEMENT
ADB_MIX, SPOS
**
**Fluid cavity definition
**
*FLUID CAVITY, NAME=ADB_MIX_CAV, MIXTURE, REF NODE=ADB_MIX_REF, 
SURFACE=ADB_MIX_SURF, AMBIENT PRESSURE=1.0E5, ADDED VOLUME=0.10, 
MINIMUM VOLUME=0.1375, ADIABATIC

AIR, 0.6
NITROGEN, 0.4
**=============================
**      CAVITY V
**=============================
*SYSTEM
8, 0, 0
*NODE, NSET=HYDRAULIC
51, 0., 0., 0.
52, 0.5, 0., 0.
53, 0.5, 0.5, 0.
54, 0., 0.5, 0.
55, 0., 0., 0.5
56, 0.5, 0., 0.5
57, 0.5, 0.5, 0.5
58, 0., 0.5, 0.5
**
** Cavity Ref. node 
**
*NODE, NSET=HYDRAULIC_REF
599, 0.25, 0.25, 0.25
**
** Elements defined such that all normals point inward
**
*ELEMENT, TYPE=SFM3D4R, ELSET=HYDRAULIC
51, 52, 53, 54, 51
52, 58, 57, 56, 55
53, 55, 56, 52, 51
54, 56, 57, 53, 52
55, 57, 58, 54, 53
56, 58, 55, 51, 54
*SURFACE, NAME=HYDRAULIC_SURF, TYPE=ELEMENT
HYDRAULIC, SPOS
**
**Fluid cavity definition
**
*FLUID CAVITY, NAME=HYDRAULIC_CAV, BEHAVIOR=LIQUID, REF NODE=HYDRAULIC_REF, 
SURFACE=HYDRAULIC_SURF, AMBIENT PRESSURE=1.0E5, ADDED VOLUME=0.10, 
MINIMUM VOLUME=0.1375

**
**Fluid behavior definition
**
**
**Pneumatic fluids
**
*FLUID BEHAVIOR, NAME=AIR
*MOLECULAR WEIGHT
0.0289
*CAPACITY, TYPE=POLYNOMIAL
28.110, 1.967E-3, 4.802E-6, -1.966E-9, 0.0
*FLUID BEHAVIOR, NAME=NITROGEN
*MOLECULAR WEIGHT
0.028
*CAPACITY, TYPE=POLYNOMIAL
26.092, 8.218E-3, -1.976E-6, -0.1592E-9, 0.0444E6
**
**Hydraulic fluid
**
*FLUID BEHAVIOR, NAME=LIQUID
*FLUID DENSITY
1000
*FLUID BULK MODULUS
4.0E6, 0
1.0E6, 300
*FLUID EXPANSION, ZERO=100
1.0E-5, 0
4.0E-5, 300
*ELSET, ELSET=DISP_BC
14,24,34,44,54
*ELSET, ELSET=FIX_BC
16,26,36,46,56
*NSET, NSET=DISP_BC, ELSET=DISP_BC
*NSET, NSET=FIX_BC, ELSET=FIX_BC
*NSET, NSET=DISP_MONITOR
12,22,32,42,52
*BOUNDARY
DISP_BC, 1, 3
FIX_BC, 1, 3
*ELSET, ELSET=ELSET_ALL
ISO_1GAS
ISO_MIX
ADB_1GAS
ADB_MIX
HYDRAULIC
*NSET, NSET=QA_TEST_ISO_1GAS_REF
199
*NSET, NSET=QA_TEST_ISO_MIX_REF
299
*NSET, NSET=QA_TEST_ADB_1GAS_REF
399
*NSET, NSET=QA_TEST_ADB_MIX_REF
499
*NSET, NSET=QA_TEST_HYDRAULIC_REF
599
**
**Material defintion
**
*SURFACE SECTION, ELSET=ELSET_ALL
**
**Initial conditions
**
*INITIAL CONDITIONS, TYPE=TEMPERATURE
ISO_1GAS_REF, 20
ISO_MIX_REF, 20
ADB_1GAS_REF, 200
ADB_MIX_REF, 200
HYDRAULIC_REF, 20
*INITIAL CONDITIONS, TYPE=FLUID PRESSURE
ISO_1GAS_REF, 2E5
ISO_MIX_REF, 2E5
ADB_1GAS_REF, 2E5
ADB_MIX_REF, 2E5
*AMPLITUDE, NAME=RAMP1, VALUE=ABSOLUTE
0, 2.0E5, 1, 4.0E5
*AMPLITUDE, NAME=RAMP
0, 0, 1, 1
**
**Step 1: Prescribe pressure boundary condition
**
*STEP
*DYNAMIC, EXPLICIT, DIRECT USER CONTROL
0.001, 1
*BOUNDARY, AMPLITUDE=RAMP1
ISO_1GAS_REF, 8, 8, 4E5
ISO_MIX_REF, 8, 8, 4E5
ADB_1GAS_REF, 8, 8, 4E5
ADB_MIX_REF, 8, 8, 4E5
*BOUNDARY, AMPLITUDE=RAMP
HYDRAULIC_REF, 8, 8, 4E5
*output,field,var=pre
***output request for QA 
*nset,nset=QA_TEST_ALL
QA_TEST_ISO_1GAS_REF,QA_TEST_ISO_MIX_REF,
QA_TEST_ADB_1GAS_REF,QA_TEST_ADB_MIX_REF,
QA_TEST_HYDRAULIC_REF
*output,field,number interval=1
*NODE OUTPUT, NSET=QA_TEST_ALL
U
*********
*OUTPUT, HISTORY, TIME INTERVAL=0.25
*energy output,variable=preselect
*NODE OUTPUT, NSET=QA_TEST_ISO_1GAS_REF
PCAV, CVOL, CSAREA, CMASS
*NODE OUTPUT, NSET=QA_TEST_ISO_MIX_REF
PCAV, CVOL, CSAREA, CMASS
**
**CTEMP is available only for adiabatic fluid cavities 
**
*NODE OUTPUT, NSET=QA_TEST_ADB_1GAS_REF
PCAV, CVOL, CSAREA, CMASS, CTEMP
*NODE OUTPUT, NSET=QA_TEST_ADB_MIX_REF
PCAV, CVOL, CSAREA, CMASS, CTEMP
*NODE OUTPUT, NSET=QA_TEST_HYDRAULIC_REF
PCAV, CVOL, CSAREA, CMASS
*NODE OUTPUT, NSET=DISP_MONITOR
U1
*END STEP
**
**Step 2: Prescribe temperature only for isothermal and hydraulic fluid 
**        cavities so that temperature in all the cavities will be the same.
**
*STEP
*DYNAMIC, EXPLICIT, DIRECT USER CONTROL
0.001, 1
*BOUNDARY, OP=NEW
FIX_BC, 1, 3, 0
DISP_BC, 1, 3, 0
*TEMPERATURE
ISO_1GAS_REF, 200
ISO_MIX_REF, 200
HYDRAULIC_REF, 200
*END STEP
**
**Step 3: Apply displacement BC to change cavity volume
**
*STEP
*DYNAMIC, EXPLICIT, DIRECT USER CONTROL
0.001, 1
*BOUNDARY, OP=NEW, TYPE=DISPLACEMENT, AMPLITUDE=RAMP
FIX_BC, 1, 3, 0
DISP_BC, 1, 1, -0.25
DISP_BC, 2, 3, 0
*END STEP
**
**Step 4: Decrease cavity volume further such that cavity volume is less than 
**        the minimum volume specified in the fluid cavity definition
**
*STEP
*DYNAMIC, EXPLICIT, DIRECT USER CONTROL
0.001, 1
*BOUNDARY, OP=MOD, TYPE=DISPLACEMENT, AMPLITUDE=RAMP
DISP_BC, 1, 1, -0.12
*END STEP