The observed flow enhancement in highly confining geometries is believed to be caused by fluid velocity slip at the solid wall surface. Here we present a simple and highly accurate method to predict this slip using equilibrium molecular dynamics. Unlike previous equilibrium molecular dynamics methods, it allows us to directly compute the intrinsic wall-fluid friction coefficient rather than an ...

The mixing noise in jet engine exhaust is one of the main noise sources in aviation. Nozzle lip serrations, commonly called chevrons, are one of the technologies deployed to address the issue in modern civilian aircraft. These nozzle serrations impinge on the shear layer and change its dynamics; the jet plume becomes lobed or serrated near the nozzle in a time-averaged sense, but reverts to a r...

Localized deformation such as shear bands, compaction bands, dilation bands, combined shear/compaction or shear/dilation bands, fractures, and joint slippage are commonly found in rocks. Thus, modeling their inception, development and propagation, and effect on stress response is important with regard to making informed engineering design decisions involving these materials. Following a GulfRoc...

The production of carbon nanotube (CNT) yarns possessing high strength and toughness remains a major challenge due to the intrinsically weak interactions between “bare” CNTs. To this end, nanomechanical shear experiments between functionalized bundles of CNTs are combined with multiscale simulations to reveal the mechanistic and quantitative role of nanotube surface functionalization on CNT-CNT...

We study the asymptotics of front speeds of the reaction-diffusion equations with Kolmogorov-Petrovsky-Piskunov (KPP) nonlinearity and zero mean stationary ergodic Gaussian shear advection on the entire plane. By exploiting connections of KPP front speeds with the almost sure Lyapunov exponents of the parabolic Anderson problem, and with the homogenized Hamiltonians of Hamilton-Jacobi equations...

This communication reports the use of an electrohydrodynamic surface shear force to selectively manipulate colloid-surface interactions. We demonstrate the selection of strongly (specifically) bound biomolecule-functionalized colloidal beads over more weakly (non-specifically) bound beads using a tuneable alternating current electrohydrodynamic (ac-EHD) force, which drives lateral fluid motion ...

Using a photon scanning tunneling microscope ~operating alternatively at the wavelengths of 594 and 633 nm! with shear-force feedback we image the topography of silver colloid fractals simultaneously with a near-field intensity distribution. We observe that near-field optical images exhibit spatially localized ~within 150–250 nm! intensity enhancement by one to two orders of magnitude. These br...

In this study, the effect of fire flame on punching shear strength steel fiber reinforced concrete flat plates was experimentally investigated using nine half-scale specimens with dimensions 1500×1500 mm and a total thickness 100 mm. The main variables comprised volume fraction 0, 1, 1.5% burning steady state temperature 500 600 °C. were divided into three groups, each group consists specimens....