conservation of energy in VIV
 

hello everyone,

I recently used pimplefoam to calculate vortex-induced vibration to verify the energy conservation of the flow field. I understand that the equations of incompressible flow require only the conservation of mass and momentum, because the temperature field does not change with time, and naturally satisfies the conservation of energy. But strangely enough, I output the flux of the following formula and find that there is no way to conserved it(see Attach Files).

My simplified energy conservation equation is this: the power of the shear stress and surface pressure is equal to the rate of change of kinetic energy of the flow field and the boundary momentum flux. That's item 2,4,5 in the picture. However, the output results are not quite the same, and the kinetic energy change rate of the flow field is much higher than other terms. Does anyone have any experience with that? Thank you very much. (Please remind me if you need other materials)