November 3, 2023 at 12:12 pmOluwagbemiga FabunmiSubscriberI am a research associate at Teesside University who is studying the mechanics of moisture ingression in encapsulant materials used of solar cell encapsulation. Currently, I am engaged in a study on modelling moisture ingress using ANSYS FLUENT software. However, I've encountered a significant challenge. Many research papers I've come across have used COMSOL Multiphysics to accurately capture this effect. Conversely, my challenge arises when using ANSYS FLUENT to model permeable encapsulant materials. I have discovered that in ANSYS FLUENT, one must define the material as porous, with the porosity value ranging from 0 to 1 (0 representing solid and impermeable, 1 signifying full permeability).However, during the simulation, ANSYS FLUENT seems to employ the porosity of the material to determine its moisture concentration at saturation. For example, with a material porosity of 0.5, the moisture concentration is consistently 0.277 kg/m^3. Even with varying materials and permeabilities, this value remains unchanged. It appears that the permeability only influences the rate at which the material saturates, resulting in higher concentrations over time, but the same moisture concentration at saturation.I am utilizing a multiphase approach for this analysis, employing water vapor and air as the fluids and monitoring plots of water vapor concentration over time. To provide further clarity, I have attached images of the plots illustrating this behaviour.
November 6, 2023 at 1:03 pmSRPAnsys Employee
You mentioned that you are using a porous media model. Verify that you have set up the porous media properties correctly. The porosity and permeability values should be defined in a way that accurately represents the material you are simulating, and make sure you have defined the material properties accurately, including moisture diffusivity and other relevant properties for the encapsulant material.
November 6, 2023 at 6:55 pmOluwagbemiga FabunmiSubscriber
I really appreciate your earlier response. As you suggested, I have carefully reviewed and input all the necessary information into ANSYS Fluent for modeling moisture ingress. The goal is to simulate water ingress into EVA and PVB back sheets, using an accelerated approach based on the IEC 61215 Damp heat test conditions, specifically at 85°C temperature and 85% humidity.
Here's a concise summary of the key parameters I've employed in the simulation:
- EVA and PVB cube with dimensions 26 x 26 x 26 mm
- Mesh size: 0.5mm
- Moisture applied to one side of the cube (single inlet, no outlet)
EVA Material Properties:
- Diffusion Coefficient (as a function of 85°C temperature): 1.30598e-9 m^2/s
- Converted to fluid velocity: 5.023e-8 m/s
- Permeability (as a function of 85°C temperature): 3.205806e-12 m^2
- Converted to viscous resistance: 1/Permeability = 3.11934e11 m^-2
- Porosity: 0.1
PVB (Back Sheet) Material Properties:
- Diffusion Coefficient: 7.53453e-9 m^2/s (as a function of 85°C temperature):
- Converted to fluid velocity: 2.8979e-7 m/s
- Permeability: 2.98197e-12 m^2 (as a function of 85°C temperature):
- Viscous resistance: 3.35349e11 m^-2
- Porosity: 0.1
I have carefully ensured the accuracy of these parameters, and with your confirmation, I would greatly appreciate your expert guidance in setting up the simulation step by step.
My work email address is email@example.com
Your support in this endeavor would be of immense value to my research, and I look forward to your response.
Thank you for your time and consideration.
- You must be logged in to reply to this topic.
Boost Ansys Fluent Simulations with AWS
Earth Rescue – An Ansys Online Series
- legend min and max
- Ensight hot iron palette from an image
- Streamlines in EnSight using MRI data
- Import MRI data into Ensight
- FLUENT APPLICATIION ERROR
- Total Surface Heat Flux Calculation in Fluent
- Difference between “total pressure” and “absolute pressure”?
- Drop Test of a Water-Filled Tube
- Minimum Orthogonal Quality Less than 0.01 For Transonic Airfoil Flow Analysis
- obtaining pressure distribution by making points in ansys
© 2023 Copyright ANSYS, Inc. All rights reserved.