title: Breakdown parameter for kinetic modeling of multiscale gas flows.
abstract: Multiscale methods built purely on the kinetic theory of gases provide information about the molecular velocity distribution function. It is therefore both important and feasible to establish new breakdown parameters for assessing the appropriateness of a fluid description at the continuum level by utilizing kinetic information rather than macroscopic flow quantities alone. We propose a new kinetic criterion to indirectly assess the errors introduced by a continuum-level description of the gas flow. The analysis, which includes numerical demonstrations, focuses on the validity of the Navier-Stokes-Fourier equations and corresponding kinetic models and reveals that the new criterion can consistently indicate the validity of continuum-level modeling in both low-speed and high-speed flows at different Knudsen numbers.
authors.affiliation: James Weir Fluids Laboratory, Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow G1 1XJ, United Kingdom.
authors.forename: Jianping
authors.initials: J
authors.lastname: Meng
authors.affiliation: Department of Mechanical & Aerospace Engineering, Indian Institute of Technology Hyderabad, Ordnance Factory Estate Yeddumailaram 502205, India.
authors.forename: Nishanth
authors.initials: N
authors.lastname: Dongari
authors.affiliation: School of Engineering, University of Edinburgh, Edinburgh, EH9 3 JL, United Kingdom.
authors.forename: Jason M
authors.initials: JM
authors.lastname: Reese
authors.affiliation: James Weir Fluids Laboratory, Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow G1 1XJ, United Kingdom.
authors.forename: Yonghao
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D003198:Computer Simulation; D005740:Gases / Q000737:chemistry*; D007700:Kinetics; D008956:Models, Chemical; D011789:Quantum Theory; D012212:Rheology / Q000379:methods*
chemical_list: D005740:Gases