*HEADING
 : UFLUID TEST USING F2D2 
(1x1x1 BLOCK, USER DEFINED FLUID)
*RESTART, WRITE, FREQ=99
*NODE, NSET=CAVITY-1_NODES
  1, 1., 1.
  2, 2., 1.
  3, 2., 2.
  4, 1., 2.
  5, 3., 1.
  6, 3., 3.
  7, 1., 3.
*ELEMENT, TYPE=CPE4, ELSET=STRUCTURE
  1,  2,  5,  6,  3
  2,  3,  6,  7,  4 
*SOLID SECTION, ELSET=STRUCTURE, MATERIAL=ELAS
*MATERIAL, NAME=ELAS
*ELASTIC
 1.0E6
*SURFACE,TYPE=ELEMENT,NAME=CAV1
 1, S4
 2, S4
*FLUID CAVITY, NAME=CAVITY1, BEHAVIOR=FLUID, SURFACE=CAV1, REFNODE=1
 1.0
*FLUID BEHAVIOR, NAME=FLUID,USER
**
**
**              SPRINGS
**
*ELEMENT, TYPE=SPRING1, ELSET=SPRINGY1
21, 4
*SPRING, ELSET=SPRINGY1
2, 
1.E-8,
*BOUNDARY
2,  1, 2, 0.0
4,  1, 1, 0.0
*INITIAL CONDITIONS, TYPE=TEMPERATURE
1, 200.
*EQUATION
2, 
3, 1, 1.0, 2, 1, -1.0
2, 
3, 2, 1.0, 4, 2, -1.0
**
**              STEP 1: APPLY LOAD AT T=200
**
*STEP, NLGEOM
*STATIC
.2, 1.
*MODEL CHANGE, REMOVE
 STRUCTURE
*CLOAD
4, 2, -100.
*NODE PRINT
U,NT11,PCAV,CVOL
*OUTPUT,FIELD,FREQ=99
*NODE OUTPUT
U,NT,
*ENERGY PRINT
*OUTPUT,HISTORY,FREQUENCY=1
*ENERGY OUTPUT,VARIABLE=PRESELECT
*END STEP
**
**              STEP 2: INCREASE FLUID TEMPERATURE TO 300
**
*STEP, NLGEOM
*STATIC
.5, 1.
*TEMPERATURE
1, 300.
*END STEP
**
**              STEP 3: ADD 5.0 UNITS OF MASS AT T=300
**
*STEP, NLGEOM
*STATIC
.5, 1.
*FLUID FLUX
1, 5.0
*END STEP
**
**              STEP 4: REMOVE 5.0 UNITS OF MASS AT T=300
**
*STEP, NLGEOM
*STATIC
.5, 1.
*FLUID FLUX
1, -5.0
*END STEP
**
**              STEP 5: DECREASE FLUID TEMPERATURE TO 200
**
*STEP, NLGEOM
*STATIC
.5, 1.
*TEMPERATURE
1, 200.
*FLUID FLUX,OP=NEW
*END STEP