Super Computers:

  • HPC clusters at the Center for High Performance Computing at the University of Utah

Experimental:

  • Laser Flash Apparatus – Thermal Conductivity measurement
  • Electron microscopy (TEM, SEM, STEM)
  • Fourier-transform infrared spectroscopy (FTIR)
  • Spark plasma sintering (SPS)

We have developed several simulation/calculation packages/tools for thermal transport research:

ShengBTE – Fourphonon

https://www.shengbte.org/announcements/fourphonon-a-four-phonon-extension-module-for-shengbte

  • FourPhonon, an extension module to ShengBTE, has been released and is free to download from its GitHub repository: FourPhonon. The developers are Zherui Han (Purdue University), Xiaolong Yang (Shenzhen University), Wu Li (Shenzhen University), Tianli Feng (University of Utah) and Xiulin Ruan (Purdue University).

  • FourPhonon is a computational package that can calculate four-phonon scattering rates in crystals. It is built within the ShengBTE framework. An adaptive energy broadening scheme is implemented for the calculation of four-phonon scattering rates. In analogy with thirdorder.py in ShengBTE, we also provide a separate python script, Fourthorder.py, to calculate fourth-order interatomic force-constants. The extension module preserves all the features of the well-recognized lattice thermal conductivity solver ShengBTE, including parallelism and straightforward workflow. A detailed description of this program and its underlying formalism can be found in this arXiv preprint: FourPhonon: An extension module to ShengBTE for computing four-phonon scattering rates and thermal conductivity. We wish that this program can help researchers explore the four-phonon effects.

 

 

 


ThermoPI

  • Team: Tianli Feng, Som Shrestha, Diana Hun, Daniel Howard, Amit Rai
  • ThermoPI calculates heat flow by conduction through solids and gases and radiative heat transfer to estimate the effective thermal conductivity of porous insulation materials. More importantly, ThermoPI allows users to investigate how to reduce the effective thermal conductivity of insulation materials by changing various design parameters. User inputs include the type of solid material; structural information such as porosity, pore shape, strut fraction and pore size; gas species and pressure within the pores; and temperature. Users either select input parameters from drop-down lists or specify them. Information on the input parameters is embedded in the question marks adjacent to the input variables.
  • ThermoPI can be¬†downloaded and installed on computers with a Windows operating system. The link will be added soon.
  • The web-based version will be available soon.

 

 

 

 


Nanohub tools

  • Authors: Tianli Feng, Divya Chalise, Xiulin Ruan (2017)

    DOI: 10.4231/D33X83N62

  • This tool allows users to calculate the spectral phonon relaxation time of most, theoretically all, pristine crystalline solids with available interatomic potentials. It is designed towards a broad application, users can upload any self-defined structures/materials and use this tool to calculate the spectral phonon relaxation time. This tool is not limited to real materials, i.e., users can use this tool to simulate any artificial materials for special purposes. This tool is not only capable for 3D bulk materials, but also for most 1D and 2D materials and nanostructures such as nanowire, nanotube, nanoribbon, 2D sheet, 2D plate, etc. Its key input is the interatomic potential. For the nanostructures such as graphene/BN/MoS2/silicene/black phosphorus nanoribbon, carbon nanotube, Si nanowire, etc., and the complex structures such as Bi2Te3, Bi2Se3, SnSe, skutterudites, etc., the computation may be time-consuming due to the large number of phonon branches. We expect this tool to pave the way towards an efficient investigation of phonon and thermal transport with applications in thermal management and thermoelectric energy conversion.

    Cite this tool:

  • Authors: Tianli Feng; Xiulin Ruan (2015)

    DOI: 10.4231/D31R6N21J

  • This tool was designed for fitting phonon spectral energy, but can be also used for fitting a general data set to get the full width at half maximum (FWHM).

    The phonon spectral energy density function can be obtained from the Nanohub tool “Spectral phonon relaxation time calculation tool by using normal mode analysis based on molecular dynamics” (https://nanohub.org/tools/phononlifetime).

    Cite this tool:

 

  • Authors: Tianli Feng; Yang Zhong, Divya Chalise, Xiulin Ruan (2017)

    DOI: 10.4231/D3VH5CM12

  • This tool allows users to calculate the phonon model temperature and heat flux in nanomaterials, including nano thin films, nanoribbons, nanowires and across interfaces. The prebuilt structures include the Si, Si/Ge interface, graphene, and graphene/BN interface. Users can upload any structures to do calculations. We expect this tool to pave the way towards an efficient investigation of phonon and thermal transport with applications in thermal transport. Please upload the eigenvectors obtained elsewhere (e.g. GULP) by yourself. The MD simulation may take a long time, depending on the domain size and MD steps you assign.

    Cite this work:

    • Tianli Feng, Wenjun Yao, Zuyuan Wang, Jingjing Shi, Chuang Li, Bingyang Cao, and Xiulin Ruan, “Spectral analysis of nonequilibrium molecular dynamics: Spectral phonon temperature and local nonequilibrium in thin films and across interfaces”, Phys. Rev. B 95, 195202 (2017).
    • Tianli Feng; Yang Zhong, Divya Chalise, Xiulin Ruan (2017), “Spectral analysis of non-equilibrium molecular dynamics,” https://nanohub.org/tools/spectralnemd (DOI: 10.4231/D3VH5CM12)