摘要 :
Based on a quantitative analogy between developing laminar flows in curved pipes and orthogonally rotating straight pipes, a corresponding analogy of forced convective heat transfer in the entry regions of the pipes is described t...
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Based on a quantitative analogy between developing laminar flows in curved pipes and orthogonally rotating straight pipes, a corresponding analogy of forced convective heat transfer in the entry regions of the pipes is described through similarity arguments and computational studies. Three-dimensional developments of these flows are characterized by secondary flows due to the centrifugal or the Coriolis forces. Similarity considerations taking the secondary flow into account suggest a remarkable Effect of the Prandtl number or the heat transfer structure, which is demonstrated by The computational results. When the curvature parameter large, it is shown that the Development of the temperature fields and the Nusselt numbers of the two flows are Similar when the governing parameters and the Prandtl numbers of he two flows are Equal.
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摘要 :
Buoyancy-induced secondary flows in a heated pipe rotating about a parallel axis are similar to those in a stationary horizontal heated pipe. The effect of buoyancy on fully developed laminar flows and heat transfer in rotating pi...
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Buoyancy-induced secondary flows in a heated pipe rotating about a parallel axis are similar to those in a stationary horizontal heated pipe. The effect of buoyancy on fully developed laminar flows and heat transfer in rotating pipes and in horizontal pipes in studied by similarity analysis and computations. The similarity analysis reveals that the flows are characterized by a new fundamental parameter, K_LB, and the Prandtl number, P_r; K_LB plays a role of Peclet number in the cross-section and P_r determines the sensitivity of the axial primary flow to secondary flow.
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摘要 :
Fully developed laminar flow in a curved square duct rotating about a center of curvature is investigated by similarity arguments, computational studies and use of experimental data. Similarity arguments suggest that the flow char...
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Fully developed laminar flow in a curved square duct rotating about a center of curvature is investigated by similarity arguments, computational studies and use of experimental data. Similarity arguments suggest that the flow characteristic are governed by four parameters: the Dean number K_LC, the body force ratio F, the curvature parameter λ and the Rossby number Ro. By using the computed flow patterns, the flow structure is elucidated for a wide range of these parameters.
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摘要 :
The fluid flowing in rotating heated curved pipes is subjected to three body forces: centrifugal, Coriolis and buoyant forces. Fully developed laminar flow in rotating coiled pipes is investigated through similarity arguments and ...
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The fluid flowing in rotating heated curved pipes is subjected to three body forces: centrifugal, Coriolis and buoyant forces. Fully developed laminar flow in rotating coiled pipes is investigated through similarity arguments and computational studies. The thermal boundary conditions at the wall are uniform wall heat flux axially and uniform wall temperature peripherally. Flow and heat transfer characteristics are elucidated for the case when they are governed by four parameters: Dean number, Prandtl number, body force ratio and buoyancy parameter. Detailed structures of Velocity and temperature fields are shown for wide range of these parameters.
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摘要 :
A regular series of silver-carbon mixed cluster ions: AgmC2n(m=3, 5, 7, 9; n=1, 2, 3) has been found by mass spectrometry. This regularity is not destroyed by the energetic collisions of the cluster ions with argon atoms. Remarkab...
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A regular series of silver-carbon mixed cluster ions: AgmC2n(m=3, 5, 7, 9; n=1, 2, 3) has been found by mass spectrometry. This regularity is not destroyed by the energetic collisions of the cluster ions with argon atoms. Remarkable differences are observed in the chemical species produced between the cluster ions containing odd numbers of silver atoms and those containing even numbers of silver atoms. Size-selected reactions of the cluster ions with argon clearly show the magic numbers effect, in addition to the even-odd difference. The mechanism of formation of silver-carbon mixed cluster ions is studied. The authors propose that the mixed cluster ions are produced on a silver surface through decomposition and dehydrogenation of hydrocarbon molecules contained in the background gas of the ionization chamber. This picture is consistent with observations from scanning tunneling microscopy.
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