Economic conditions were unsteady, with several depressions and recoveries, while business organizations were transformed into hierarchical and inclusive corporate structures.
The unsteady expansion of an ideal gas into a vacuum is studied in one-dimensional planar and spherical geometries.
The governing equations in the water are therefore those of unsteady potential flow, while those in the air are of lubrication.
Whenever the jet impinged on the cavity wall the latter became rough, unsteady and opaque as in the bottom lefthand corner of figure 1 (c).
These large-scale instabilities give rise to unsteady flow throughout the inner layer.
The driving mechanism results from unsteady coupling between flame structure and acoustic waves through temperature fluctuations.
This approximation, according to which the unsteady terms in the equations of motion of the flow can be neglected, is adopted here.
The present analyses advance the previous quasi-steady models by being formulated for a fully unsteady flow system, with no time-derivative terms being neglected.