what is the segnification of turbulent energy and turbulent dissipation used in flow3d software

The significance of using a turbulence model in any CFD code (Flow3D, FLUENT, or whatever) is to be able to have some understanding of the production of energy (from sources like viscous friction and external heating) and also of the dissipation of energy, which is transfer of the energy generated to the rest of the system through smaller and smaller "eddies".

But it is not limited to just energy... also transfered is the mass and momentum.