An Experimental Study for Simulation of Pneumatic Conveying. Lift and Drag Applied to a Sphere in High-Reynolds-Number Linear Shear Flows.

Yamamoto, Fujio; Koukawa, Mitsuo; Monya, Hideki; Teranishi, Atsushi; Miyamoto, Hiroyuki

doi:10.1299/jsmeb.36.294

Cited by 4 publications

(5 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The present results also show that for a ÿxed shear rate, the drag increase is larger at higher Reynolds numbers. These trends are similar to those found in the previous numerical studies of Dandy and Dwyer (1990), Salem and Oesterle (1998), and Kurose and Komori (1999) as well as the experimental study by Yamamoto et al (1993).…”

Section: Lift and Dragsupporting

confidence: 91%

“…On the other hand, at Re = 400, the pressure on the bottom side is lower than that on the top side, and the net pressure contribution to the lift is directed toward the low-velocity side. Lower pressure on the low-velocity side at higher Reynolds numbers was also observed in an experiment of Yamamoto et al (1993).…”

Section: Lift and Dragsupporting

confidence: 69%

“…Once the Reynolds number is greater than 300, the lift coe cient becomes nearly constant at about −0:07 for all the cases considered here. According to the experimental measurements at Re ¿ 4000 by Yamamoto et al (1993), and the numerical results of Kurose and Komori (1999) for ÿ between 0.2 and 0.8, the magnitude of the lift coe cient increases with the increase of the shear rate, which is not observed in the present computations up to Re = 500.…”

Section: Lift and Dragcontrasting

confidence: 57%

“…A numerical result that the lift force is biased toward the low-velocity side on a circular cylinder in a shear ow at Re = 400 was previously reported in a study of Jordan and Fromm (1972). The lift acting toward the low-velocity side at much higher Re was also observed in a experimental study of Yamamoto et al (1993) who measured the lift acting on a sphere at Re between 4000 and 35 000. Considering opposing results presented by the previous studies, a numerical investigation of the dependency of lift direction on the Reynolds number is still of interest.…”

Section: Introductionsupporting

confidence: 55%

“…This results in the clockwise torque which is deÿned as positive in this study, as shown in Fig.7.Fig.8displays the variation of the lift coe cients at di erent Reynolds numbers for ÿ = 0:05; 0:1; and 0.2. It also includes the range of lift coe cients measured byYamamoto et al (1993) for…”

mentioning

confidence: 99%

See 4 more Smart Citations

The effects of shear flow on the unsteady wakes behind a sphere at moderate Reynolds numbers

Lee

Wilczak²

2000

Fluid Dyn. Res.

View full text Add to dashboard Cite

Numerical simulations to investigate the e ects of shear ow on wakes behind a sphere were carried out using a three-dimensional ÿnite element method. The time-dependent Navier-Stokes equations were solved by a modiÿed explicit time integration scheme. The Reynolds number, deÿned by the sphere diameter and oncoming velocity at its center, ranged from 20 to 500. Linear shear is assumed, and the dimensionless shear rate, deÿned as the vertical gradient of oncoming shear ow, was varied from 0.0 to 0.2. Extensive comparisons were made between the present computed results and available experimental and numerical investigations, and showed that they are in close agreement. Computed lift force was directed toward the low velocity side for Re ¿ 50 whereas it was toward the high velocity side for Re ¡ 50. In addition, drag forces showed slight increases compared to those in a uniform ow. The Reynolds number, at which vortex shedding begins, was found to be lower than that in a uniform ow and was a function of the shear rate. Vortex shedding frequency also increases with the Reynolds number and the shear rate. The irregularity of the vortex shedding and the oscillation of the vortex detachment location appearing in uniform and low shear ows at Re = 500 vanishes when high shear was present.

show abstract