F225 Heat Transportation by an Oscillatory Flow in a Double Tube

Ishii, Yoshihisa; Zhang, Pingping; Kawai, Ryohei; Hishida, Makoto; Tanaka, Gaku

doi:10.1299/jsmeted.2005.445

Cited by 1 publication

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2). Ishii et al [11] mentioned that the vortex developed in this region during the inflow phase is closely related to the strength of the unidirectional flow, by changing the oscillating frequency under the condition of fixed diameter ratio χ = 1.0. The present study is suited for investigating the effect of the inlet vortex as the intensity of the inlet shear layer is controlled by changing the diameter ratio χ with keeping the inflow rate the same.…”

Section: Development Of Vorticity In the Cold-reservoir Sidementioning

confidence: 99%

“…Ishii et al [11] introduced a novel oscillation-controlled transport device featuring coaxial doublelayered pipes connecting the two reservoirs through circular and annular openings at the respective ends.…”

Section: Introductionmentioning

confidence: 99%

“…This simple structure has, literally, the same topology as the respiratory system of birds; given periodic oscillations to the fluids at the circular and annular openings with a certain phase difference, apparent steady flows develop superposed with reciprocal flow components in both inner (circular) and outer (annular) conduits [11]. The apparent steady flows are in the opposite directions to each other in the conduits, making a unidirectional current, as if circulating from the inner tube to the annulus and back to the inner tube again.…”

Section: Introductionmentioning

confidence: 99%

“…Further, Ishii et al [11] applied it to a heat exchanger by connecting the both ends of the double-tube structure to the cold and hot reservoirs, as shown in Fig. 1.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Role of Vortical Structures on the Forced Convective Heat Transfer in Oscillation-Controlled Coaxial-Pipe Heat Exchanger

2015

View full text Add to dashboard Cite

A numerical simulation of an oscillation-controlled heat-transport coaxial pipe is carried out for studying the flow structure and heat transport characteristics. The heat-transport pipe connects the hot and cold reservoirs, and the cold and hot fluids are discharged with the anti-phase reciprocal waves through circular and annular openings at the ends of the chamber, respectively. By changing the diameter ratio of the circular opening to the inner tube, a unidirectionally circulating flow is observed to develop spontaneously. The flow rate of the unidirectional current is found to be approximately inversely-proportional to the diameter ratio. While the amount of transported heat increases with the flow rate of the unidirectional current (especially when generating strong vortices at the edge of the inner tube) for both cases of thermally-insulated and fully-conductive inner wall, the optimal heat transport performance is attained (not in association with the strongest unidirectional flow) when making zero-averaged vorticity in the cold-end region. For the case of the conductive inner wall, the heat loss across the wall is suppressed with decreasing the diameter ratio, due to the development of the strong jet and radially surrounding shear layer that separate the outer hot fluid from the inner cold fluid.

show abstract

Section: Development Of Vorticity In the Cold-reservoir Sidementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…Further, Ishii et al [11] applied it to a heat exchanger by connecting the both ends of the double-tube structure to the cold and hot reservoirs, as shown in Fig. 1.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations