The thermal conductivity of nanostructures and nanostructured materials differs significally from the macroscopic laws of bulk materials. Mastering the heat dissipation enables the creation and conceptualization of nanocomposite or nanomaterials for specific thermal management purposes. For lattice thermal conductivity alone, multiple interesting non Fourier phenomena have been explored recently such as thermal rectification, phonon filtering, phonon diffraction and interference, as well hydrodynamic effects. These exotic phenomena opens the way for new application. For instance, thermal rectification enables the creation of smart material that can dissipate heat or insulate depending on the ambient conditions, diffraction of phonons allows focussing heat on a specific spot to heat it or on the contrary shield it from heat. Phonon filtering on the other end may be useful in the field of phononic computing where information is carried by phonons. In this presentation, these particular thermal transport phenomena at the nanoscale are explored using atomistic simulations. Amorphous/crystalline Silicon nanocomposites and nanomaterials are used, thus one can achieve thermal management without requiring the use of complex crystalline structures or the use of raw materials.