Solver

Currently, OpenBTE supports the anisotropic-MFP-BTE

\[\mathbf{F}_\mu \cdot \nabla \tilde{T}_\mu + \tilde{T}_\mu = \left[ \sum_{\mu''} \gamma_{\mu''} \right]^{-1}\sum_{\mu'}\gamma_{\mu'} \tilde{T}_{\mu'}\]

where \(\mathbf{F}=\mathbf{v}_\tau\tau_\mu\) is the vectorial MFP and \(\gamma_\mu =C_\mu/\tau_\mu\). The first step in solving this equation is to provide a first guess for the lattice temperature via solving the standard heat conduction equation. To this end, we use the Fourier solver

from openbte import Fourier

fourier     = Fourier(mesh,mat.thermal_conductivity,boundary_conditions,\
                      effective_thermal_conductivity=effective_kappa)

Finally, we can solve the BTE with

from openbte import BTE_RTA

bte     = BTE_RTA(mesh,mat,boundary_conditions,fourier=fourier,\
                  effective_thermal_conductivity=effective_kappa)

The result of the simulations can then be consolidated in a OpenBTEResults object

from openbte.objects import OpenBTEResults

results = OpenBTEResults(mesh=mesh,material = mat,solvers={'bte':bte,'fourier':fourier})

Lastly, we can save the results with

results.save()

where the file state.db is saved in you current directory. Optionally you can define a custom filename, without including the .db suffix. Once ready for postprocessing, results can be load with

from openbte.objects import OpenBTEResults

results = OpenBTEResults.load()

where an optional filename can be specified.