*HEADING
: AQUA Spatial variation of steady state current velocity.
**
** AQUA steady state currents are tested with respect to spatial
** variation. A pipe element fully constrained and submerged,
** is subjected a steady state current which varies with respect to 
** the x-axis. For this simple case the total drag force can be 
** analytically determined for each member and compared to the 
** memeber reaction forces.
**
** EXPECTED RESULTS:
**
**      R = 1/4*rho*Cd*D*vel^2*L
**
** where    R = Member reaction at either node
**        rho = fluid density = 1.987
**         Cd = Drag Coefficient = 1.2
**          D = Effective Diameter = 2.0
**        vel = Steady current velocity = fn(x)
**          L = Member Length = 10
**         vf = 2.896
**
** ------------------------------------------------------------
**   x     |    vel      |  elem      |   Nodes    |    Ri
** ------------------------------------------------------------
**  50.0   |  1.0*vf     |   1        |      1     |   -100
**         |             |            |    101     |   -100
** ------------------------------------------------------------
** 200.0   |  2.0*vf     |   2        |      2     |   -400
**         |             |            |    102     |   -400
** ------------------------------------------------------------
** 300.0   |  3.0*vf     |   3        |      3     |   -900
**         |             |            |    103     |   -900
** ------------------------------------------------------------
** 450.0   |  3.0*vf     |   3        |      4     |   -900
**         |             |            |    104     |   -900
** ------------------------------------------------------------
** 750.0   |  1.5*vf     |   4        |      5     |   -225
**         |             |            |    105     |   -225
** ------------------------------------------------------------
** 950.0   |  0*vf       |   5        |      6     |      0
**         |             |            |    106     |      0
**
**
**
*AQUA
0.0,40.0,32.2,1.987
**
**    vx     vy      vz    elev    x1  x2
**-----------------------------------------------------
2.896179274, 0.0,    0.0,   0.0, 100.0, 0.0
2.896179274, 0.0,    0.0,  40.0, 100.0, 0.0
8.688537822, 0.0,    0.0,   0.0, 300.0, 0.0
8.688537822, 0.0,    0.0,  40.0, 300.0, 0.0
8.688537822, 0.0,    0.0,   0.0, 600.0, 0.0
8.688537822, 0.0,    0.0,  40.0, 600.0, 0.0
0.0,         0.0,    0.0,   0.0, 900.0, 0.0
0.0,         0.0,    0.0,  40.0, 900.0, 0.0
** ---------------------------------------------------
*NODE, NSET=NALL
1,   50.0, 20.0, 0.0
2,  200.0, 20.0, 0.0
3,  300.0, 20.0, 0.0
4,  450.0, 20.0, 0.0
5,  750.0, 20.0, 0.0
6,  990.0, 20.0, 0.0
** -----------------
101, 50.0, 30.0, 0.0
102,200.0, 30.0, 0.0
103,300.0, 30.0, 0.0
104,450.0, 30.0, 0.0
105,750.0, 30.0, 0.0
106,990.0, 30.0, 0.0
*ELEMENT, TYPE=PIPE21, ELSET=PIPES
1, 1, 101
2, 2, 102
3, 3, 103
4, 4, 104
5, 5, 105
6, 6, 106
*BEAM SECTION, SECTION=PIPE, MATERIAL=STEEL, ELSET=PIPES
1.0, 0.05
*ELSET, ELSET=EALL
PIPES, 
*MATERIAL, NAME=STEEL
*DENSITY
 0.2836
*ELASTIC
30.0E6, 0.3
*BOUNDARY
NALL,1,2
NALL,6,6
*RESTART, WRITE
*STEP
Normal distributed drag force FDD.
*DYNAMIC, EXPLICIT
 ,.2
*DLOAD, OP=NEW
EALL, FDD, 1.0, 2.0, 1.2, 1.0
*OUTPUT, FIELD
*NODE OUTPUT
 RF
*OUTPUT, HISTORY
*NODE OUTPUT, NSET=NALL
 RF
*END STEP