This study numerically investigates heat transfer augmentation using water-based Al₂O₃ and CuO nanofluids flowing in a triangular cross-sectional duct under constant heat flux in laminar flow conditions. The Al₂O₃/water nanofluids with different volume fractions (0.1%, 0.5%, 1%, 1.5%, and 2%) and CuO/water nanofluids with various volume fractions (0.05%, 0.16%, 0.36%, 0.5%, and 0.8%) are employ...

In this paper, we analytically investigate the coupling of light from liquid-core waveguides to conventional solid-core waveguides and a series of other optical properties of liquid waveguides in order to gauge the practicality of such a system for use in microfluidically reconfigurable photonic systems. A finite element model of the system was constructed and relevant properties such as mode f...

Abstract. We demonstrate here that a single physical phenomenon, specifically, naturally changing balance between intensities of temperature advection and diffusion in the viscous ice media, may influence entire spectrum Pleistocene variability from orbital to millennial timescales.

The objective of this study is to numerically investigate the convective heat transfer of water-based Al2O3 nanofluids flowing through a square cross-section duct with a constant heat flux under laminar flow conditions. The effects of nanoparticle concentration and Peclet number on the heat transfer characteristics of Al2O3-water nanofluids are investigated. The nanoparticle diameter is 25 nm a...

An organelle which absorbs (or secretes) a particular factor will find its mass transfer rate diffusion-limited if it is stationary with respect to its ambient cytoplasm; but organellar motion will raise that limit as a non-decreasing function of the Peclet number P. It is shown analytically that (i) no Whitehead paradox need be encountered in the creeping flow regime and (ii) the flux of the f...

We study solute dispersion in channels with periodically varying apertures. Based on an approximate analytical solution of the flow equation, we study the impact of the geometry and molecular diffusion on effective solute dispersion analytically using the method of local moments. We also study the problem numerically using a random walk particle tracking method. For transport in parallel shear ...

The conditional dissipation and diffusion for a passive scalar with an imposed mean gradient are studied here. The results are obtained for an elementary model consisting of a random shear flow with a simple time-periodic transverse sweep. As the Peclet number is increased, scalar intermittency is observed; the scalar probability density function departs strongly from a Gaussian law. As a resul...

A simple Taylor-series analysis is made of the finite-difference formulations of the convection terms of convection-diffusion equations. A limitation is derived on grid Peclet number and grid size for a formulation to produce the expected numerical results. To verify the theory, the systematic numerical computations were carried out of a simple one-dimensional convection-diffusion equation. The...