1,721,007 research outputs found
Analysis of damping forces exerted by single-component gases and mixtures in high-frequency MEMS devices
Full text linkFluid instabilities in precessing ellipsoidal shells.Theoretical background and numerical modeling.
No full textComment on "Velocity slip coefficients based on the hard-sphere Boltzmann equation" [Phys. Fluids 24, 022001 (2012)]
No full textHigher order slip according to the linearized Boltzmann equation with general boundary conditions
No full textIn the present paper, we provide an analytical expression for the first- and second-order velocity slip coefficients by means of a variational technique that applies to the integrodifferential form of the Boltzmann equation based on the true linearized collision operator and the Cercignani–Lampis scattering kernel of the gas–surface interaction. The polynomial form of the Knudsen number obtained for the Poiseuille mass flow rate and the values of the velocity slip coefficients are analysed in the frame of potential applications of the lattice Boltzmann methods in simulations of microscale flows.</jats:p
From a microscopic to a macroscopic model for Alzheimer disease: Two-scale homogenization of the Smoluchowski equation in perforated domains
Full text linkIn this paper, we study the homogenization of a set of Smoluchowski’s discrete diffusion–coagulation equations modeling the aggregation and diffusion of (Abeta-amyloid peptide (Abeta), a process associated with the development of Alzheimer’s disease. In particular, we define a periodically perforated domain obtained by removing from a fixed domain (the cerebral tissue) infinitely many small holes of size epsilon (the neurons), which support a non-homogeneous Neumann boundary condition describing the production of Abeta. by the neuron membranes. Then, we prove that, when epsilon tends to zero, the solution of this micromodel two-scale converges to the solution of a macromodel asymptotically consistent with the original one. Indeed, the information given on the microscale by the non-homogeneous Neumann boundary condition is transferred into a source term appearing in the limiting (homogenized) equations. Furthermore, on the macroscale, the geometric structure of the perforated domain induces a correction in that the scalar diffusion coefficients defined at the microscale are replaced by tensorial quantities
Variational approach to gas flows in microchannels on the basis of the Boltzmann equation for hard-sphere molecules
No full textScaling laws for damping forces exerted by different gases in the near-free molecular flow regimes.
No full textDamping forces exerted by rarefied gas mixtures in micro-electro-mechanical system devices vibrating at high frequencies
Full text linkOn the influence of the eulerian velocity pdf closure on the eddy diffusion coefficient.
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