- #1

- 1

- 0

I am beginner in fluent v15, and I want to simulate the temperature change as a function of time in the phase change materials "PCM" and the heat thermal fluid "HTF" and the PCM fusion Front.

Regarding the geometry I chose to work with two coaxial tubes: the inner tube contains the heat thermal fluid and the outer tube contains the PCM

for meshing I appointed the input, output and symmetry area of HTF and PCM. Also the entry, exit and the symmetry of the wall between the PCM and the HTF

The set up steps followed are:

General ==> Type: based pressure, velocity formulation: absolute, time: transient

Model ==> volume of fluid with 2 stages in number eulerian, energy, melting and solidification

Materials ==> PCM characteristics: density, solidius and liquidus temperature , thermal conductivity, pure solvent latent heat and thermal expansion coefficient

for the HTF I chose to work with liquid water

Phases ==> Primary phase pcm, Secondary phase HTF

Cell Condition box ==> Wall (phase mixture, Type: Solid)

HTF (phase mixture type: Fluid, Fluid porosity: 1)

PCM (phase mixture type: Fluid, Fluid porosity: 1)

NB: I want to determine the porosity of the fluid depending on the temperature f (T)

- f(T) = 0 if T < Ts

- f(T) = 1 if T > Tm

- 0 < f(T) = (T -Ts) / (Tm - Ts ) < 1 if Ts < T < Tm

but I don't know how to do it with new input parameter

Boundary Conditions ==> in this stage I entered the HTF input velocity and the inlet and outlet temperatures of the HTF, PCM and WALL but I find myself stuck facing problem with the symmetry area of HTF and PCM.

and other boundary conditions appear as: wall-htf-wall, wall-htf-shadow-wall, wall-pcm, wall-pcm-wall, wall-pcm shadow-wall, wall-wall

but I do not know what to choose for thermal conditions: temperature convection heat flow or or ...

and if for example I chose the heat flux how can I calculate the heat generation rate and the heat flux.

I will be very grateful for your help and thank you in advance.

Best regards;