Fluid–Fluid Interfaces in Steady Motion

Rose, Walter

doi:10.1038/191242a0

Cited by 134 publications

(49 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…part is directly linked to the structural homogeneTheir generation mechanism has been described ity of the material. It is strongly influenced by by the Fountain flow, 4,5 which is easily shown by shrinkages and residual stresses induced by the the incorporation of markers in the melt. 6 The injection process.…”

Section: Introductionmentioning

confidence: 99%

Temperature‐dependent influence of molecular orientation and internal stresses on the deformation of injection‐molded polypropylene parts

Lafranche

Pabiot

1998

J of Applied Polymer Sci

View full text Add to dashboard Cite

Local orientation measures by infrared dichroism and thermal stress measures by dilatometric analysis of image (DAI) have made it possible to quantify the evolution of the structure versus the thickness of the injected plastic parts. The stiffness local properties on the one hand, and thermal expansion on the other hand, have then been established. Deformation measures made in temperature have pointed out its deformation induced by thermal stresses and that attributed to the gradient of molecular orientation and cristallinity of the polymer. A calculation of plastic part deformation constituted of elementary layers whose Young's modulus and coefficients of thermal expansion values have been previously evaluated, has enabled us to corroborate experimental results.

show abstract

Section: Introductionmentioning

confidence: 99%

Temperature‐dependent influence of molecular orientation and internal stresses on the deformation of injection‐molded polypropylene parts

Lafranche

Pabiot

1998

J of Applied Polymer Sci

View full text Add to dashboard Cite

show abstract

“…The flow immediately behind an advancing interface when one fluid displaces another from a narrow channel is commonly known as fountain flow (Rose, 1961). Fluid entering the front region decelerates in the direction of flow and acquires a transverse velocity, spilling outward toward the wall.…”

Section: Introductionmentioning

confidence: 99%

The kinematics of fountain flow in mold‐filling

1987

View full text Add to dashboard Cite

Moldability criteria and process optimization for both reactive and thermoplastic injection molding hinge on the mold-filling step. The fluid mechanics of the filling step is typically described in terms of a onedimensional main flow and a complex two-dimensional flow near the advancing front, often termed the "fountain flow." A unique apparatus which permits direct observation of the fountain flow in a rectangular cavity is described. The motion of tracer lines as well as the pathlines have been photographed for both Newtonian and shear-thinning liquids. The data show clearly the main flow, the transition to the front flow, and the deceleration and acceleration zones in the fountain flow, which lead to a "mushrooming" of the tracer line.In addition, Galerkin finite-element analysis is used to predict the isothermal free-surface flow of a Newtonian liquid near the advancing front between parallel plates. The most interesting visualization of the calcu-

show abstract

“…It constitutes the hydraulic connection between the channel proper and the levees: the lava flows from the channel proper through the frontal zone into the levees. In the frontal zone, streamlines diverge showing a three-dimensional fountain flow velocity distribution (Rose 1961;Mavridis et al 1986). Lava elements decelerate and stretch laterally as they approach the slower moving lava-air interface at the flow front.…”

Section: The Unit Flowsmentioning

confidence: 98%

On the Mechanisms of Lava Flow Emplacement and Volcano Growth: Arenal, Costa Rica

Borgia¹,

Linneman²

1990

IAVCEI Proceedings in Volcanology

View full text Add to dashboard Cite

Arenal Volcano is composed of a hierarchical series of geologic units: unit flow, composite flow, lava field, and lava armor. Volume-limited unit flows are emplaced at short time intervals to make up composite flows. Composite flows form lava fields, and lava fields in turn, constitute the lava armor (the volcano). Tephra and lava breccias are selectively eroded from the steep slopes of the volcano by heavy rains and contribute little to the actual shape of the cone. This constructive process has important consequences for the distribution of the age of lava on a composite cone. We show that lava of significantly different ages may be juxtaposed at all scales from the unit flow, to the composite flow, to the lava field, and to the lava armor. These relations are applicable to the time sequential sampling of a composite volcano.Detailed observations of the dynamic behavior of unit flows indicate that two dimensionless parameters determine the distribution of lava between an active, flowing component and a passive, stationary component. The first parameter, f, is a measure of how much lava the front uses to advance relative to how much it uses to build up levees. The second parameter, q, is the fraction of lava that is able to drain out of the channel when no more lava from the vent feeds the flow. Both parameters have a primary role in determining the final dimensions of a lava flow. These parameters may be calculated from observations of lava flowing onto different topography and at different times after effusion. This data set may allow the prediction of f and q for future flows, and as a consequence, the final flow length along possible flow paths is also predictable.The development of a thermal structure within the flow plays a critical role in the dynamic evolution of a unit flow. The weight of a cold, highly viscous crust at the surface of the flow actively modifies the stress distribution in the flow and controls the rate of processes such as front velocity, levee formation, and growth of surges. We propose that for a given flux of lava there is a critical channel length beyond which the flow accelerates triggering the separation of the flow from its source near the vent. Thus, the unit flows are volume-limited. Based on this hypothesis we derive a relation for the velocity and position of the flow front at any time after effusion has started, assuming the time functions of f, q, and flow rate are known. We find that the length of a unit flow is directly proportional to f, q, and the flow rate and it is inversely proportional to the cross-sectional area of the channel and to the sine of the slope. These relations also hold for composite flows.Finally, by making the approximation that a composite flow grows to a constant slope we derive equations for the evolution of lava fields and the growth of the volcanic structure. These relations explain the asymmetric distribution, areal extent, and slope of the various lava fields at Arenal and allow us to infer the position of buried craters and contacts. Re...

show abstract

Fluid–Fluid Interfaces in Steady Motion

Cited by 134 publications

References 3 publications

Temperature‐dependent influence of molecular orientation and internal stresses on the deformation of injection‐molded polypropylene parts

Temperature‐dependent influence of molecular orientation and internal stresses on the deformation of injection‐molded polypropylene parts

The kinematics of fountain flow in mold‐filling

On the Mechanisms of Lava Flow Emplacement and Volcano Growth: Arenal, Costa Rica

Contact Info

Product

Resources

About