Coupling Boltzmann and Navier–Stokes Equations by Half Fluxes

✍ Scribed by Patrick Le Tallec; François Mallinger

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 787 KB
• Volume: 136
• Category: Article
• ISSN: 0021-9991
• DOI: 10.1006/jcph.1997.5729

✦ Synopsis

a global Navier-Stokes model. At first, the coupling was achieved by imposing friction boundary conditions on the We introduce an adaptative coupling of the Boltzmann and Navier-Stokes equations to compute hypersonic flows around a vehiobstacle [4]. This coupling requires that the Boltzmann cle at high altitude. The coupling is achieved by matching half fluxes and the Navier-Stokes domains include the obstacle as at the interface of the Boltzmann and Navier-Stokes domains. The boundary, and the Navier-Stokes domain overlaps comdomains are determined automatically by computing local kinetic

pletely the Boltzmann domain. This strategy works well for residuals on a preliminary Navier-Stokes solution. Our method is developed here for monoatomic gases. Different numerical results very low Knudsen numbers but is always rather expensive.

illustrate its validity and limits. ᮊ 1997 Academic Press Moreover, rarefied effects are miscalculated by the Navier-Stokes solver when the Knudsen number increases.