The radiation (reaction, Robin) boundary condition for the diffusion equation is widely used in chemical and biological applications to express reactive boundaries. The underlying trajectories of the diffusing particles are believed to be partially absorbed and partially reflected at the reactive boundary, however, the relation between the reaction constant in the Robin boundary condition and t...

A particle-based mesoscopic model for enzyme kinetics is constructed and used to investigate the influence of diffusion on the reactive dynamics. Enzymes and enzyme-substrate complexes are modeled as finite-size soft spherical particles, while substrate, product, and solvent molecules are point particles. The system is evolved using a hybrid molecular dynamics-multiparticle collision dynamics s...

Abstract: We consider the system of equations governing a steady flow of polyatomic isothermal reactive gas mixture. The model covers situation when the pressure depends on species concentration and when the diffusion coefficients for each of the species are density-dependent. It is shown that this problem admits weak solution provided the adiabatic exponent for the mixture γ is grater then 7 3 .

We consider the evolution of a reactive soluble substance introduced into the Poiseuille flow in a slit channel. The reactive transport happens in presence of dominant Péclet and Damköhler numbers. We suppose Péclet numbers corresponding to Taylor’s dispersion regime. The two main results of the paper are the following. First, using the anisotropic perturbation technique, we derive rigorously a...

The dynamics of one-dimensional detonations predicted by a one-step irreversible Arrhenius kinetic model with the inclusion of mass, momentum, and energy diffusion were investigated. A series of calculations in which activation energy is varied, holding the length scales of diffusion and reaction constant, was performed. As in the inviscid case, as the activation energy increases, the system go...

For finite adspecies mobility, the lattice-gas monomer-dimer (AϩB 2) surface reaction model exhibits a discontinuous transition from a stable reactive steady state to a stable A-poisoned steady state, as the impinge-ment rate P A for A increases above a critical value P*. The reactive ͑poisoned͒ state is metastable for P A just above ͑below͒ P*. Increasing the surface mobility of A enhances metasta...

Laminar hydrocarbon flames, which have adiabatic flame speeds on the order of a meter per second, are conventionally described by a leading convective-diffusive zone followed by an energyreleasing reactive-diffusive region. On the other hand, combustion induced by a strong shock wave is typically modeled as a convective-reactive balance with negligible diffusion, which may be called a convectiv...

High-resolution porous structures of catalyst layers (CLs) including non-precious metal catalysts (NPMCs) or Pt for proton exchange membrane fuel cells are reconstructed using the quartet structure generation set. The nanoscale structures are analyzed in terms of pore size distribution, specific surface area, and phase connectivity. Pore-scale simulation methods based on the lattice Boltzmannme...

A hybrid weighted essentially non-oscillatory (WENO)/centered-difference numerical method, with low numerical dissipation, high-order shock-capturing, and structured adaptive mesh refinement (SAMR), has been developed for the direct numerical simulation of the multicomponent, compressive, reactive Navier-Stokes equations. The method enables accurate resolution of diffusive processes within reac...