An unstable mixing layer, in conjunction with free surface wave effects, can give rise to well-defined subharmonic oscillations of the vortex shedding frequency provided certain streamwise phase conditions are satisfied.
In particular conditions, the laminar flow tends to become unstable, mixing with eddies and counter eddies: the initial phase of this transition stage consists of perturbations within the boundary layer interacting with shape discontinuities, in particular, changes of vessel lumen diameter, surface curvatures and roughness or velocity changes and relatively high flow velocity [24, 25].
AMERICAN Apparel has long been an unstable mix of good and bad qualities.
The movie is a beautifully photographed but slightly unstable mix of documentary footage, location shooting, and studio-bound staged pieces.
After a holiday in Greece, marked by his increasingly unstable mix of lust and guilt, comes a deadly confrontation when Léa traces him to Martha's Vineyard.
But, because they typically bring to it an unstable mix of abstraction and narcissism, their judgments tend to be absolute, when nothing in politics ever is.
But this is, after all, the deep south, in both history and literature the home of an unstable mix of trauma, drama and melodrama.
Kadima, his new party, has three problems: it has no clear platform, no obvious leader, and contains an unstable mix of ambitious rivals drawn from opposing parties.
His choreography (following the wilderness years, there would be very little dancing) was uneven in its quality, and his three-year Stravinsky project, launched in 2005, was an unstable mix of the brilliant, the quixotic and the wilfully indulgent.
The Middle Eastern combination of low productivity and high birth rate makes for an unstable mix, and by all indications the Arab countries, in such matters as job creation, education, technology, and productivity, lag ever farther behind the West.
It was clear the Cruz speech would be the dominant event of the evening, if only for that unstable mix of performance and authenticity that characterizes, among other media, pro-wrestling.
