Backward-facing step (BFS) is a model that provides several applicative features in engineering. The complex phenomena of BFS flow have crucial impact on any application. Therefore, this study comprehensively investigates the characteristics with various shapes. backward-facing (F-BFS) fillets were tested at intervals Reynolds number 50 smaller than Re 400 using CFD approach. Based computationa...

Results are presented from a numerical study of transient growth experienced by infinitesimal perturbations to flow in an axisymmetric pipe with a sudden 1–2 diametral expansion. First, the downstream reattachment point of the steady laminar flow is accurately determined as a function of Reynolds number and it is established that the flow is linearly stable at least up to Re=1400. A direct meth...

Incompressible, axisymmetric laminar flow downstream of a porous expansion is simulated. Effect of the Darcy number and inertia coefficient on flow and heat transfer characteristics downstream of the expansion is investigated. The simulation revealed circulation downstream of the expansion. Decreasing the Darcy number is shown to decrease the circulation region. The Nusselt number, friction coe...

Phylogeographical studies of Nearctic songbirds conducted to date have yielded unexpectedly low levels of genetic differentiation and weak phylogeographical structure in mitochondrial DNA lineages as compared with species studied in Neotropical areas. Factors leading to this pattern may include (i) gene flow, (ii) population expansions from bottlenecked populations, and (iii) selective sweeps. ...