|
[Sponsors] |
Question about Solidification/melting model in Fluent |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
December 17, 2022, 16:15 |
Question about Solidification/melting model in Fluent
|
#1 |
New Member
Yogesh
Join Date: Sep 2022
Posts: 12
Rep Power: 4 |
Hello all,
I am simulating the solidification of a metallic PCM using the solidification/melting model in Ansys Fluent. The PCM is enclosed in a solid container with a pipe flow of air beneath it, which removes heat from the PCM. I'm assuming constant volume and density for the PCM. The specific heat capacity and thermal conductivity are defined to be temperature dependent with large changes at the solidus temperature. The PCM liquidus temperature is 579°C and the solidus temperature is 571°C. The Pure solvent melting heat is set to the melting enthalpy of the PCM (478590 J/kg). There is a mass flow rate inlet (1.48e-4 kg/s) and a pressure outlet (zero gauge pressure) in the pipe. The PCM and the solid are initialized using patch tool to 650°C. There are also contact resistances defined at PCM - Solid interface walls using shell conduction layer (temperature (phase) dependent). The simulation works but the temperature curve of the PCM (see image - red curve) at the end of solidification shows a gradual change, whereas in reality the temperature changes steeply upon reaching the solidus temperature. The reason is that there are liquid portions in the PCM volume even upto 20°C below the solidus temperature. Below is a contour of the PCM mass fraction at 555°C (15°C below the solidus temperature). Only when the whole volume is solidified, the temperature starts dropping as expected. I wish to get the liquid fraction to zero closer to the solidus temperature and see a temperature curve similar to the experiment. I've tried the following so far.
Laminar model, double-precision enabled, second order bounded implicit transient formulation, Coupled pressure-velocity solver, Second order accuracy for pressure, momentum and energy. With time step size 1s, I run it for first 5-10 time steps. I'm getting good convergence of solution (1e-6 for continuity, momentum and 1e-12 for energy). Thereafter, I use a time step size of 10s. Note: The contact resistances are still to be adjusted. Therefore, the time of heat discharge differs from the experiment. Which parameter or property controls the range in which the liquid fraction changes from 1 to 0? Thank you! |
|
Tags |
conjugate heat transfer, fluent, phase change material, solidification/melting |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
looking for a smart interface matlab fluent | chary | FLUENT | 24 | June 18, 2021 10:07 |
interFoam wave propagation and explosion of Courant number and residuals | ChiaraViola | OpenFOAM Running, Solving & CFD | 1 | June 26, 2019 06:36 |
question about turbulence model selection and sensitivity | karananand | Main CFD Forum | 1 | February 26, 2010 05:41 |
Advanced Turbulence Modeling in Fluent, Realizable k-epsilon Model | Jonas Larsson | FLUENT | 5 | March 13, 2000 04:27 |