A multiplicative decomposition of Poiseuille number on rarefaction and roughness by lattice Boltzmann simulation

摘要: Poiseuille number of rarefied gas flow in channels with designed roughness is studied and a multiplicative decomposition on the effects rarefaction proposed. The numerical methodology based mesoscopic lattice Boltzmann method. In order to eliminate effect compressibility, incompressible model used periodic boundary imposed inlet outlet channel. combined bounced condition applied simulate velocity slip wall boundary. Numerical results reveal two opposite that gradient friction factor near increase as increases; meanwhile, increments lead corresponding decrement factor. An empirical relation which contains has better physical meaning proposed form decomposition, then validated by available experimental results.