Turbulent structures and characteristics of flows past a vertical surface-piercing finite circular cylinder

Large-eddy simulation of the flow past a surface-piercing circular cylinder is performed to investigate the effects of Reynolds and Froude numbers using a high fidelity orthogonal curvilinear grid solver. The present study extends and supports the conclusions of the precursory work for medium Reynolds and Froude numbers. Organized periodic vortex shedding is observed in deep flow. At the interface, the organized periodic vortex shedding is attenuated and replaced by small-scale vortices. The streamwise vorticity and outward transverse velocity generated at the edge of the separated region cause the weakened vortex shedding at the interface. The main source of the streamwise vorticity and the outward transverse velocity at the interface is the lateral gradient of the difference between the vertical and transverse Reynolds normal stresses.

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The method of replication affects metal film granularity and resolution

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100155517 ◽

1989 ◽

Vol 47 ◽

pp. 708-709

Author(s):

George C. Ruben

Keyword(s):

Electron Beam ◽

High Resolution ◽

Film Thickness ◽

Single Molecule ◽

Metal Film ◽

Vertical Surface ◽

High Resolution Imaging ◽

Controllable Factors ◽

Resolution Imaging

Single molecule resolution in electron beam sensitive, uncoated, noncrystalline materials has been impossible except in thin Pt-C replicas ≤ 150Å) which are resistant to the electron beam destruction. Previously the granularity of metal film replicas limited their resolution to ≥ 20Å. This paper demonstrates that Pt-C film granularity and resolution are a function of the method of replication and other controllable factors. Low angle 20° rotary , 45° unidirectional and vertical 9.7±1 Å Pt-C films deposited on mica under the same conditions were compared in Fig. 1. Vertical replication had a 5A granularity (Fig. 1c), the highest resolution (table), and coated the whole surface. 45° replication had a 9Å granulartiy (Fig. 1b), a slightly poorer resolution (table) and did not coat the whole surface. 20° rotary replication was unsuitable for high resolution imaging with 20-25Å granularity (Fig. 1a) and resolution 2-3 times poorer (table). Resolution is defined here as the greatest distance for which the metal coat on two opposing faces just grow together, that is, two times the apparent film thickness on a single vertical surface.

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Slip Effects on a Mixed Convection Flow of a Third-Grade Fluid Near the Orthogonal Stagnation Point on a Vertical Surface

Прикладная механика и техническая физика ◽

10.15372/pmtf20160317 ◽

2016 ◽

Keyword(s):

Mixed Convection ◽

Stagnation Point ◽

Vertical Surface ◽

Third Grade ◽

Convection Flow ◽

Mixed Convection Flow ◽

Third Grade Fluid ◽

Slip Effects ◽

Grade Fluid

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Low Reynolds number flow around and heat transfer from a heated circular cylinder

International Review of Applied Sciences and Engineering ◽

10.1556/irase.1.2010.1-2.3 ◽

2010 ◽

Vol 1 (1-2) ◽

pp. 15-20 ◽

Cited By ~ 1

Author(s):

B. Bolló

Keyword(s):

Reynolds Number ◽

Circular Cylinder ◽

Lift Coefficient ◽

Reynolds Numbers ◽

Low Reynolds Numbers ◽

Reynolds Number Flow ◽

Two Dimensional Flow ◽

Number Flow ◽

Low Reynolds ◽

Increasing Temperature

Abstract The two-dimensional flow around a stationary heated circular cylinder at low Reynolds numbers of 50 < Re < 210 is investigated numerically using the FLUENT commercial software package. The dimensionless vortex shedding frequency (St) reduces with increasing temperature at a given Reynolds number. The effective temperature concept was used and St-Re data were successfully transformed to the St-Reeff curve. Comparisons include root-mean-square values of the lift coefficient and Nusselt number. The results agree well with available data in the literature.

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