Bifurcations of two-dimensional into three-dimensional wave regimes for a vertically flowing liquid film

1991 ◽  
Vol 25 (5) ◽  
pp. 741-745 ◽  
Author(s):  
Yu. Ya. Trifonov
Keyword(s):  
Liquid Film ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Flowing Liquid ◽  
Dimensional Wave

Characteristics of Flow and Heat-and-Mass Transfer in a Falling Liquid Film With Three-Dimensional Interfacial Waves

2002 ◽  
Author(s):  
Takao Nagasaki ◽  
Hirokuni Akiyama ◽  
Hiroshi Nakagawa ◽  
Yutaka Ito
Keyword(s):  
Mass Transfer ◽  
Liquid Film ◽  
Heat And Mass Transfer ◽  
Mass Transfer Rate ◽  
Vertical Wall ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Large Wave ◽  
Calculated Mass ◽  
Dimensional Wave

Numerical simulations have been made on the flow and heat-and-mass transfer in a laminar liquid film falling down along a vertical wall by using a boundary-fitted coordinate system. The development of a two-dimensional wave was successfully predicted, which consists of a large solitary wave and ripple waves in front of it. In the large wave a circulating flow exists, and the heat and mass transfer is enhanced by the wave. Further, it was shown by a three-dimensional calculation that a two-dimensional wave becomes unstable with the increase of Re number, resulting in U-shaped three-dimensional wave. The mass transfer rate increases with the transition from two-dimensional to three-dimensional waves. The calculated mass transfer coefficient roughly agrees with empirical correlations.

Two- and three-dimensional locomotion of the nematode Nippostrongylus brasiliensis

Parasitology ◽  
1990 ◽  
Vol 101 (2) ◽  
pp. 301-308 ◽  
Author(s):  
D. L. Lee ◽  
W. D. Biggs
Keyword(s):  
Sodium Alginate ◽  
Intestinal Mucosa ◽  
Three Dimensional ◽  
Viscous Medium ◽  
Nippostrongylus Brasiliensis ◽  
Two Dimensional ◽  
Immune Rejection ◽  
Forward Movement ◽  
Helical Wave ◽  
Dimensional Wave

Locomotion of adult Nippostrongylus brasiliensis has been studied in saline, in 0.6% agar, in sodium alginate of different viscosities and amongst sand grains in these media. In saline the nematode formed two-dimensional waves but there was little forward progression. Amongst sand grains in saline the nematode moved forwards by thrusting against sand grains, but thigmokinetic behaviour later resulted in quiescence. In 0.6% agar and in alginates of weak viscosity the nematode produced two-dimensional waves and sometimes a three-dimensional helical wave which resulted in forward movement. The formation of three-dimensional waves and the distance travelled increased with increasing viscosity up to 4% sodium alginate and also amongst sand gains in these media. In 8% sodium alginate the nematode became coiled like a spring but remained almost stationary. The three-dimensional wave is formed with torsion and obtains thrust from the viscous medium. In the intestine of the host thrust will be obtained from the mucus and villi of the intestinal mucosa. The ability of this nematode to move by two-and three-dimensional undulatory propulsion is probably related to its complex ridged cuticle. Attention is drawn to the role that increased viscosity of mucus may play in entrapping nematodes during their immune rejection.

A three-dimensional supramolecular framework built from two-dimensional wave-shaped layers

2006 ◽  
Vol 59 (8) ◽  
pp. 883-890 ◽  
Author(s):  
Linlin Fan ◽  
Chao Qin ◽  
Yangguang Li ◽  
Enbo Wang ◽  
Xinlong Wang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Two Dimensional ◽  
Supramolecular Framework ◽  
Dimensional Wave

Instabilities of three-dimensional viscous falling films

1992 ◽  
Vol 242 ◽  
pp. 529-547 ◽  
Author(s):  
S. W. Joo ◽  
S. H. Davis
Keyword(s):  
Evolution Equation ◽  
Three Dimensional ◽  
Falling Film ◽  
Two Dimensional ◽  
Wave Evolution ◽  
Strongly Nonlinear ◽  
Long Wave ◽  
Threshold Amplitude ◽  
Permanent Wave ◽  
Dimensional Wave

A long-wave evolution equation is used to study a falling film on a vertical plate. For certain wavenumbers there exists a two-dimensional strongly nonlinear permanent wave. A new secondary instability is identified in which the three-dimensional disturbance is spatially synchronous with the two-dimensional wave. The instability grows for sufficiently small cross-stream wavenumbers and does not require a threshold amplitude; the two-dimensional wave is always unstable. In addition, the nonlinear evolution of three-dimensional layers is studied by posing various initial-value problems and numerically integrating the long-wave evolution equation.

The development of three-dimensional wave-packets in unbounded parallel flows

1968 ◽  
Vol 32 (4) ◽  
pp. 801-808 ◽  
Author(s):  
M. Gaster ◽  
A. Davey
Keyword(s):  
Wave Packet ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Mean Flow ◽  
Physical Plane ◽  
Parallel Flows ◽  
Flow Velocity Profile ◽  
The Stability ◽  
Special Case ◽  
Dimensional Wave

In this paper we examine the stability of a two-dimensional wake profile of the form u(y) = U∞(1 – r e-sy2) with respect to a pulsed disturbance at a point in the fluid. The disturbed flow forms an expanding wave packet which is convected downstream. Far downstream, where asymptotic expansions are valid, the motion at any point in the wave packet is described by a particular three-dimensional wave having complex wave-numbers. In the special case of very unstable flows, where viscosity does not have a significant influence, it is possible to evaluate the three-dimensional eigenvalues in terms of two-dimensional ones using the inviscid form of Squire's transformation. In this way each point in the physical plane can be linked to a particular two-dimensional wave growing in both space and time by simple algebraic expressions which are independent of the mean flow velocity profile. Computed eigenvalues for the wake profile are used in these relations to find the behaviour of the wave packet in the physical plane.

FREQUENCY DOMAIN RECONSTRUCTION FOR PHOTO- AND THERMOACOUSTIC TOMOGRAPHY WITH LINE DETECTORS

2009 ◽  
Vol 19 (02) ◽  
pp. 283-306 ◽  
Author(s):  
MARKUS HALTMEIER
Keyword(s):  
Wave Equation ◽  
Frequency Domain ◽  
Boundary Data ◽  
Three Dimensional ◽  
Photoacoustic Tomography ◽  
Two Dimensional ◽  
Reconstruction Problem ◽  
Acoustic Data ◽  
Dimensional Wave ◽  
Frequency Domain Reconstruction

This paper is concerned with a version of photoacoustic tomography, that uses line shaped detectors (instead of point-like ones) for the recording of acoustic data. The three-dimensional image reconstruction problem is reduced to a series of two-dimensional ones. First, the initial data of the two-dimensional wave equation is recovered from boundary data, and second, the classical two-dimensional Radon transform is inverted. We discuss uniqueness and stability of reconstruction, and compare frequency domain reconstruction formulas for various geometries.

A novel (3,6)-connected CdII coordination polymer based on an ether-linked tricarboxylate ligand: synthesis, topology and luminescence sensing properties in aqueous solution

2019 ◽  
Vol 75 (12) ◽  
pp. 1666-1674
Author(s):  
Yu'e Yu ◽  
Yuqian Chen ◽  
Xiuna Mi ◽  
Suna Wang ◽  
Jing Lu
Keyword(s):  
Aqueous Solution ◽  
Coordination Polymer ◽  
Three Dimensional ◽  
Isophthalic Acid ◽  
Water Stability ◽  
Two Dimensional ◽  
Carboxylate Ligands ◽  
Strong Luminescence ◽  
Solvothermal Conditions ◽  
Dimensional Wave

A novel three-dimensional coordination polymer, namely, poly[[diaquabis(μ-4,4′-bipyridine)bis{μ3-5-[(2-carboxyphenoxy)methyl]isophthalato}tricadmium(III)] dimethylformamide monosolvate 2.5-hydrate], {[Cd3(C16H9O7)2(C10H8N2)2(H2O)2]·2C3H7NO·5H2O} n , was obtained by the reaction of ether-linked 5-[(2-carboxyphenoxy)methyl]isophthalic acid (H3 L) with CdII salts in the presence of 4,4′-bipyridine (bpy) under solvothermal conditions. In this complex, the CdII centres are connected by the carboxylate ligands to form two-dimensional wave-like layers, which are pillared by bpy ligands and extended into a rare three-dimensional (3,6)-connected sqc27 framework. The complex demonstrated good water stability and strong luminescence emissions. It not only possesses excellent luminescence sensing activities toward Fe3+ and Cr2O7 2− in aqueous solution, but can also distinguish between Cr2O7 2− and CrO4 2− by luminescence. Furthermore, it could be simply and quickly regenerated at least five times. A study of the sensing mechanism indicated that luminescence quenching may be related to the energy competition between the complex and sensing analytes.

Formation of rivulets in isothermal liquid film flow during transition to a three-dimensional wave regime

2014 ◽  
Vol 40 (11) ◽  
pp. 1031-1034 ◽  
Author(s):  
S. V. Alekseenko ◽  
A. V. Bobylev ◽  
V. V. Guzanov ◽  
D. M. Markovich ◽  
S. M. Kharlamov
Keyword(s):  
Liquid Film ◽  
Film Flow ◽  
Three Dimensional ◽  
Wave Regime ◽  
Liquid Film Flow ◽  
Dimensional Wave

On the spatio-temporal stability of primary and secondary crossflow vortices in a three-dimensional boundary layer

2002 ◽  
Vol 456 ◽  
pp. 85-111 ◽  
Author(s):  
WERNER KOCH
Keyword(s):  
Saddle Point ◽  
High Frequency ◽  
Wave Packets ◽  
Temporal Stability ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Dimensional Boundary ◽  
Spatio Temporal ◽  
Secondary Instabilities ◽  
Dimensional Wave

To examine possible links between a global instability and laminar–turbulent breakdown in a three-dimensional boundary layer, the spatio-temporal stability of primary and secondary crossflow vortices has been investigated for the DLR swept-plate experiment. In the absence of any available procedure for the direct verification of pinching for three-dimensional wave packets the alternative saddle-point continuation method has been applied. This procedure is known to give reliable results only in a certain vicinity of the most unstable ray. Therefore, finding no absolute instability by this method does not prove that the flow is absolutely stable. Accordingly, our results obtained this way need to be confirmed experimentally or by numerical simulations. A geometric interpretation of the time-asymptotic saddle-point result explains certain convergence and continuation problems encountered in the numerical wave packet analysis. Similar to previous results, all our three-dimensional wave packets for primary crossflow vortices were found to be convectively unstable.Due to prohibitive CPU time requirements the existing procedure for the verification of pinching for two-dimensional wave packets of secondary high-frequency instabilities could not be implemented. Again saddle-point continuation was used. Surprisingly, all two-dimensional wave packets of high-frequency secondary instabilities investigated were also found to be convectively unstable. This finding was corroborated by recent spatial direct numerical simulations of Wassermann & Kloker (2001) for a similar problem. This suggests that laminar–turbulent breakdown occurs after the high-frequency secondary instabilities enter the nonlinear stage, and spatial marching techniques, such as the parabolized stability equation method, should be applicable for the computation of these nonlinear states.

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