Experimental observation of a permanent reflectional symmetry breaking (RSB) is reported for a laminar three-dimensional wake. Based on flow visualizations, a first bifurcation from the trivial steady symmetric state to a steady RSB state is characterized at Re=340. The RSB state becomes unsteady after a second bifurcation at Re=410. It is found that this RSB regime is persistent at large Reyno...

A semi-analytical investigation has been carried out to analyze unsteady MHD second-grade flow under the Dual-Phase-Lag (DPL) heat and mass transfer model in a vertical microchannel filled with porous material. Diffusion thermo (Dufour) effects and homogenous chemical reaction are considered as well. The governing partial differential equations are solved by using the Laplace transform method w...

Scalar mixing is investigated in a decelerating turbulent round jet using direct numerical simulation. The main focus to determine and model any new self-similar states the unsteady flow as well predict centerline evolution of relevant quantities. mass fraction fluid residence time, measured by mass-weighted stream age fluid, both exhibit radial profiles statistically stationary jets. Upon stop...

Turbocharging is becoming a key technology for both Spark Ignition (SI) and diesel automotive engines. As regards gasoline engines, turbocharging can help to reduce CO2 emissions when used in conjunction with other technologies, such as engine downsizing, direct injection and variable valve actuation, all managed on the basis of appropriate control strategies. However, the successful applicatio...

The characteristics of steady granular flow in quasi-two-dimensional rotating tumblers have been thoroughly investigated and are fairly well understood. However, unsteady time-varying flow has not been studied in detail. The linear response of granular flow in quasi-two-dimensional rotating tumblers is presented for periodic forcing protocols via sinusoidal variation in the rotational speed of ...

The effects of unsteady strain rate on the burning velocity of hydrogen/air premixed flames have been studied in an opposed nozzle configuration. The numerical method employs adaptive time integration of a system of differential–algebraic equations. Detailed hydrogen/air kinetic mechanism and transport properties are considered. The equivalence ratio is varied from lean to rich premixtures in o...

The unsteady, incompressible boundary layer flow caused by an impulsively stretching surface under the influence of a transverse magnetic field is investigated. The partial differential equations governing the laminar flow, under boundary-layer approximations, are non-dimensionalised using similarity transformations and then solved numerically using an efficient, implicit finite-difference sche...