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negative DRAG,LIFT and MOMENT Coefficient,net mass flow rate is NOT ZERO...?

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Old   December 4, 2013, 02:31
Default negative DRAG,LIFT and MOMENT Coefficient,net mass flow rate is NOT ZERO...?
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Basavaraj H M
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hello every one,i'm using turbulence model k-omega sst,im trying to simulate 3D model ship in viscous flow under open channel wave BC,multiphase,

Domain-
X: -183m and 173m.
Y: -37.13m and 37.12m.
Z: -22.23539m and 18.9m.

ship size-
L-65m.
B-15m.
H-6m.

mesh size near ship 2m and far away 6m.
least mesh quality 0.5342 out of 1,

solver-pressure based,absolute,steady,gravity.

models-multiphase:VOF,open channel flow,open channel wave BC,implicit.viscous:k-omega SST.

phase:air and water.

BC:inlet=turbulence intensity 5% and turbulence length scale (.07*L).L-hydraulic diameter=6.31.(L=4*A/P),Area and perimeter.velocity 4m/s.
open channel Wave BC-2nd order stokes,shallow/intermediate waves,time period 4 sec,amplitude-1m wavelength 24.98m,phase angle zero.

oulet= backflow turbulence intensity 5% and turbulence length scale .4417(I HAVE DOUBT ABOUT THIS THINK)

Solution method:
SIMPLE
gradient-least squares cell based.
pressure- PRESTO
momentum-2nd order upwind
Volume Fraction-BGM and other are 2nd order upwind

solution control defualt, only max turbulence Viscosity ratio 1*e18.

initilization from inlet,

But im getting negative Drag, Lift and moment coefficient.net mass flow rate is not zero,reverse flow.......suggestion please Guys.
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