The Bödewadt boundary layer flow on the stationary bottom end wall of a finite rotating cylinder is very sensitive to perturbations and noise. Axisymmetric radial waves propagating inward have been observed experimentally and numerically before the appearance of spiral three-dimensional instabilities. In this study, the sensitivity and response of the finite Bödewadt flow to a harmonic modulati...

A comparison between the experimental visualization and numerical simulations of the occurrence of vortex breakdown in laminar swirling flows produced by a rotating endwall is presented. The experimental visualizations of Escudier (1984) were the first to detect the presence of multiple recirculation zones and the numerical model presented here, consisting of a numerical solution of the unstead...

The flow interception efficiency, which provides a measure of the fraction of streamlines that intercept a porous collector, is an important parameter in applications such as particle capture, filtration, and sedimentation. In this work, flow permeation through a porous circular cylinder located symmetrically between two impermeable parallel plates is investigated numerically under different fl...

For a two-dimensional fluid in a square domain with no-slip walls, new direct numerical simulations reveal that the transition from steady to chaotic flow occurs through a sequence of various periodic and quasiperiodic flows, similar to the well-known Ruelle-Takens-Newhouse scenario. For all solutions beyond the ground state, the phenomenology is dominated by a domain-filling circulation cell, ...

Nanospheres with an internal bicontinuous structure were obtained through hierarchical self-assembly of a dendritic block terpolymer in selective solvents. The self-assembly underwent a unique three stage process involving unimolecular micelle formation, multimicelle aggregation and microphase separation within a self-confined space. Reversible phase inversion of the nanospheres in response to ...

Bad atmospheric conditions appear to be the culprit in each of these cases. The unfortunate part is that these incidents could have possibly been prevented. Had the atmosphere been monitored in these three cases alone, maybe we could have prevented the six injuries and one fatality. A person in need of help while in a tank, vessel, pit, manhole or other confined space is in a confined space res...

Simple theoretical models are presented to illustrate the effects of spatial confinement and macromolecular crowding on the equilibria and rates of protein folding and binding. Confinement is expected to significantly stabilize the folded state, but for crowding only a marginal effect on protein stability is expected. In confinement the unfolded chain is restricted to a cage but in crowding the...

jet impingement heat transfer is an effective and practical approach that is employed in many industrial processes where heating, cooling, or drying is required. details of the heat or mass transfer rate have been investigated both experimentally and numerically and can be found in the published literature. in most of the numerical studies, control-volume approach has been employed to solve the...

An analytical solution for flow in the vicinity of an observation well is developed. The observation is emplaced in a homogeneous aquifer of infinite radial extent that is pumped at a constant rate, and satisfies the Theis solution. We attempt to account for the effect of an observation well on the drawdown response in a neighborhood of finite radial extent centered around the well. The model o...

In many technological applications, materials are transported by fluid flow at micro/nanometer scales. Conventionally, macroscopic apparatuses, such as syringe pumps, are used to drive the flow. This work explores the possibility of utilizing motile bacteria as microscopic pumps. We used micro-fabricated structures to confine smooth-swimming bacteria in a prescribed configuration. The flagella ...