*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