Laser Beam-Hygroscopic Aerosol Interactions

1977 ◽  
Vol 99 (2) ◽  
pp. 281-286 ◽  
Author(s):  
G. E. Caledonia ◽  
J. D. Teare

A model for the prediction of the temperature and vapor fields created about a small water droplet undergoing irradiation by a laser beam has been developed. Time-dependent and steady-state solutions of the model are discussed. Estimates of characteristic phase shifts to be expected in propagating through standard atmospheric aerosol distributions are also presented. While the model is quite general, the calculations are limited to DF laser wavelengths.

Author(s):  
K. K. Tam ◽  
P. B. Chapman

AbstractThe problem of thermal ignition in a reactive slab with unsymmetric temperatures equal to 0 and T is considered. Steady state upper and lower solutions are constructed. It is found that T plays a critical role. Results similar to the case with symmetric boundary temperatures are expected when T is small. When T is sufficiently large, there is only one steady state upper or lower solution. The time dependent problem is then considered. Phenomena suggested by studying the upper and lower steady state solutions are confirmed.


2001 ◽  
Author(s):  
Paulo J. Oliveira

Abstract Past numerical work with constant-viscosity viscoelastic fluids through planar contractions has enabled steady-state solutions to be obtained at relatively high Weissenberg numbers (We up to 10). Those solutions for the upper-convected Maxwell and Oldroyd-B models showed steady flow patterns for increasing We with the appearance of lip-vortices, vortex growth, and comer-lip vortex merging, in agreement with recent simulations and some experimental work. When similar simulations were performed with two shear-thinning viscoelastic models, namely the Phan-Thien – Tanner and the Giesekus models, steady state solutions could not be obtained beyond a certain value of We, but the solution was seen to follow a periodic unsteady flow pattern. The present paper reports preliminary numerical results which highlight the formation of the lip vortices through a sequence of time dependent events.


1965 ◽  
Vol 21 (4) ◽  
pp. 623-633 ◽  
Author(s):  
Carl E. Pearson

The nature of the steady-state viscous flow between two large rotating disks has often been discussed, usually qualitatively, in the literature. Using a version of the numerical method described in the preceding paper (Pearson 1965), digital computer solutions for the time-dependent case are obtained (steady-state solutions are then obtainable as limiting cases for large times). Solutions are given for impulsively started disks, and for counter-rotating disks. Of interest is the fact that, at high Reynolds numbers, the solution for the latter problem is unsymmetrical; moreover, the main body of the fluid rotates at a higher angular velocity than that of either disk.


1964 ◽  
Vol 14 (2) ◽  
pp. 109-128 ◽  
Author(s):  
F. Jackson

In a recent paper (1) Portnov used a form of Poisson integral to find the exact solution for the temperature distribution in a freezing semi-infinite slab occupying the region x > 0, and having an arbitrary time dependent temperature applied at the face x = 0. Previously, Boley (2) had used a method based on Duhamel's theorem to find solutions for problems involving melting, in both finite and semi-finite regions, caused by time dependent heat fluxes. Steady-state solutions have been investigated by Landau (3), Masters (4) and others (5).


1968 ◽  
Vol 2 (1) ◽  
pp. 51-57 ◽  
Author(s):  
R. C. Hewson-Browne ◽  
D. N. Burghes

This paper concerns the time-dependent motions of the cavity formed when a uniform corpuscular flux is incident on the magnetic field of a line current. The two-dimensional problem is formulated and solved with two particular classes of solutions being given; namely, the steady-state solutions and the time-history of the interaction with a cloud of flux.


2016 ◽  
Vol 46 (7) ◽  
pp. 2263-2265 ◽  
Author(s):  
Peter G. Baines ◽  
Roger L. Hughes

AbstractIn regards to the recent paper by Pedlosky and Spall (Journal of Physical Oceanography, November 2015), this comment maintains that the steady-state solutions of Rossby waves in a uniform eastward current past an island have waves on the upstream side that are not caused by the island because of inappropriate boundary conditions and the assumed form of the solution. The solutions are interesting but are not the solutions to the problem as posed in their paper. Similar upstream waves in a time-dependent numerical model are also inconsistent with linear Rossby wave theory, though the reasons for their presence are uncertain.


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