3D Heat conduction

Type - 3D
Grid - Structured Cartesian
Case - Heat Conduction
Method - Finite Volume Method
Approach - Flux based
Accuracy - First order
Scheme - Explicit
Temporal - Unsteady
Parallelized - No
Inputs:
[
Length of domain (LX,LY,LZ)
Time step - DT
Material properties - Conductivity (k or kk)
Density - (rho)
Heat capacity - (cp)
Boundary condition and Initial condition.
]
Setup :
The six boundaries are heated to 100 C, 200 C, 300 C, 400 C, 500 C and 600 C respectively.
https://sourceforge.net/projects/a3d-heat-conduction/
Solution after 10000 time steps:

Solution after 50000 time steps

Initial condition