[canderous]

I am working on a project involving analysing liquid cooling structures of electric vehicle battery packs, and am currently trying to roughly model the heat generation of an 18650 cylindrical Li-ion battery. I have come across a method proposed in a paper that I wish to replicate in some way, the only problem being the UDF is not directly covered. The methodology is described in section 3.1 of "Analysing the performance of liquid cooling designs in cylindrical lithium-ion batteries"- Matthew Yates et al. (https://www.sciencedirect.com/scienc...52152X1930461X), where it describes how the power generation per unit volume is 190,000W/m3, is run over a period of 720s, and also how the power generation is set as a function of the height of the cell aswell.*

The geometry I have is simple, it is just a cylinder with diameter 18mm and height 65mm, I wish to just have a user defined function to model the heat generation described above, so I can finally move on to modelling the cooling. I have never created a UDF before, and have no experience in programming, if this involves writing something in C. I would really appreciate any help in how to create this UDF.

Many thanks

[AlexanderZ]

you mat use DEFINE_SOURCE macro to apply heat source

algorithm I can suggest:
1. you check Z-axis zoordinate (assuming the height in z direction) look for C_CENTROID macro
2. dependint on Z coordinate you have some expression to calculate heat source

Ansys Fluent Customization manual

[canderous]

Thanks for your response Alexander,

I have had a look through the UDF manual, and looked at DEFINE_SOURCE, although the problem is writing a script like this is very much out of my depth, I have no programming experience. I did find a youtube video (https://youtu.be/Pi2hHNazhNQ) which showed a UDF for some variable heat source:

#include"udf.h"
DEFINE_SOURCE(variableheatsource, c, t, ds, eqn)
{
real time,source;
time=CURRENT_TIME;
source=10000*time;
ds[eqn] = 0;
return source;
}

I guess this is a starting point, although it of course is still not close to what I need, do you have any idea how I can convert this script to the conditions I need?

Many thanks