[Sayantan Biswas]

I'm working on Copper electro-refining/depostion in Fluent 18.2.

Suppose I’m splitting the fluid domain in multiple(3) fluid zone.One zone includes the Anode, one zone includes Cathode, another rest of the fluid domain.

Now I’m adding a source term in cell zone condition (Mass source kg/m3 –s no other source).

i) In the fluid domain (species transport model so reaction mixture) H2O, CuSO4,H2SO4 are present and at Inlet BC certain mass fraction is specified. Now what is that mass sources is representing? Is it made of mixture or particular any materials? How fluent treats this? How this source term effects the continuity and momentum equation?

The value of that specified mass source term I’m calculating from Faraday’s law; amount of mass deposited = i*M/(Z*F*1000)
i=current density, M molar conc, Z valiancy.

ii) Can I create/specify somehow that same amount of mass source; one is representing as Source (Anode) & another source representing as Sink (Cathode) may be by assigning +/- sign?

Using Species Transport model, specifying electro chemistry reaction and applying current density at Anode/Cathode, somehow electro-depostion phenomena is not occurring.

[piu58]

I wrote something in a PM, but I repeat it for all here.

All in all, there is no reason to simulate 3 zones. The electrolyte and the electrodes in form of boundary conditions are sufficient.

It depends on the questions you ask the simulation, what a complicated (or simple) model you have to set. May be, you get valuable results with a pocket calculator.

The components of the solution does not take part in the reaction of the electrodes, except copper ions of course. They don't need to be simulated, the electrical conductivity is sufficient.

If you want to take kinetic effects into account (which is normally necessary in this field). you need constants which describe it. That may be the Wagner number (simples) or the coefficients of the Butler Volmer equation. You may these evaluate by yourself if you make a test deposition in a Hull cell.

Using the Wagner number (which may be transformed into a Robin boundary condition) you may use a FEM or BEM code, or even OpenFaom/potentialFoam.

[Sayantan Biswas]

Objective of the work is study the flow behaviour of the electrolyte (an aqueous solution of CuSO4 and H2SO4 having certain concentraion)
as suitable current density is applied & how much copper is getting deposited on the cathode due to electro-chemical reaction that is occurring on solid Anode/Cathode surface.

The problem is, I've tried many different cases, but the deposition phenomena is not happening. I'm expecting there should be some variation of copper concentration contour if a plane is placed in between cathode and anode.
Variation of copper concentration should affect the flow pattern of the fluid that is closed to electrodes.
I'm specifying Cathode surface as Steel Anode surface is Copper but bottom line is the electro chemical reaction(Cu to Cu+2 &Cu+2 to Cu)
is not happening thus no copper mass concentration variation.

Splitting in different zone is an approach, idea is try to create a mass source zone and a mass sink zone. In a literature this approach is mentioned(using faraday's law).
That's why was asking what is the meaning/significance of that mass source term?

The components of solution doesn't take place that's true but their presence in fluid domain will affect the flow behaviour. I'm specifying Electrical Conductivity for the mixture as that is known from Plant Data but not for individual components.