Dissipative scheme

P.Cooke

hello all. i am a little confused and wondered if someone can point me in the right direction.

1) firstly, is the following statement true.... image a turbulent jet flow. if we over predict the dissipation of turbulent kinetic energy, then there will be less enegy and motion in the eddies to mix the jet. therefore if we DO over predict the dissipation of turbulent kinetic energy the modelled jet will mix and spread less. are these statements true???

2) secondly, based on the first points, if in solving the navier stokes equations we use say an upwind scheme, i.e. a dissiaptive scheme, what effects does this have on the same jet simulation. i would have thought the dissipation would again damp fluctuations and therefore cause less mixing? but also the upwind scheme will 'smear' the solution on the mesh and therefore 'apparently show more mixing'. what are the effects of the upwind scheme on a spreading jet and how do these effects differ from the ones discussed in the first point i made.

any comments would be great as i am (as you may tell) a little confused.