Heat Flux Calculations

Submitted by bhuvan on Thu, 10/05/2023 - 11:42

Hi Everyone,

I have been working with LIGGGHTS for the past three months. I am trying to understand how exaclty is the heat flux calculated in the program.

I am using compute wall/gran/local and compute pair/gran/local for computing the contact area, contact points, overlap and heat flux. I was able to verify the calculations to reproduce the overlap and contact area using geometry. The heat fluxes, however, remain elusive. I am refering to the equations given in documentation of fix heat/gran to determine the flux. The numbers that I get from the equations does not match the ones given in the LIGGGHTS output files. I am not sure what I am missing here. The two commands mentioned above generate outupts that are not at all the same and I am not sure I understand what they mean exactly.

Additionally, the two variable that store flux information, namely, f_directionalHeatFlux[1-3] and f_heatFlux[0], are confusing me as well. I understand that the former is a vector while the latter is a scalar but I am not sure what heat flow do they represent and how is one related to the other. Could you please help me with this confusion? It is crucial for my project that I understand this.

Thank you in advance.
Sincerely,
Bhuvan Agrawal