A validation study for various CFD models of the time-varying flow through a confined bank of cylinders is presented. The geometry approximates part of the lower plenum of a high temperature reactor and is arranged with the cylinders on equilateral triangles with pitch to diameter ratio of 1.7. Time-resolved Particle Image Velocimetry (PIV) measurement coupled with time-varying pressure measure...

We consider a reaction–diffusion equation on 3D thin porous media of thickness $$\varepsilon $$ which is perforated by periodically distributed cylinders size . On the boundary cylinders, we prescribe dynamical condition pure-reactive type. As \rightarrow 0$$ , in 2D limit resulting has source term coming from dynamical-type conditions imposed boundaries original domain.

We consider a thin multidomain of R , N ≥ 2, consisting of two vertical cylinders, one placed upon the other: the first one with given height and small cross section, the second one with small thickness and given cross section. In this multidomain we study the asymptotic behavior, when the volumes of the two cylinders vanish, of a Laplacian eigenvalue problem and of a L2-Hilbert orthonormal bas...

Here we show theoretically that swimming animals and athletes gain an advantage in force and speed by spreading their fingers and toes optimally. The larger force means larger body mass lifted and greater speed, in accord with the constructal theory of all animal locomotion. The spacing between fingers must be twice the thickness of the boundary layer around one finger. This theoretical predict...