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Buoyant jets have been a topic of interest due to their presence in various natural and industrial phenomena, as well as in our daily lives. Covering extensive literature, our focus in this review article is on free, miscible buoyant jets with small-density differences (under the Boussinesq approximation) within uniform and stagnant environments. We examine the latest research on Newtonian jet flows and expand our scope to their viscoplastic counterparts, reflecting a burgeoning trend in contemporary literature. Our analysis covers negatively buoyant, pure, and positively buoyant jets, via delving into their dynamics. This includes regime classifications and key jet characteristics, such as laminar length, penetration length, mixing behavior, velocity profiles, and turbulence parameters. In particular, the effects of the key governing dimensionless parameters, including the Reynolds number, the Froude number, the Bingham number, the viscosity ratio, and the injection angle, on these characteristics are explored. [ABSTRACT FROM AUTHOR]

The impact of an isolated mesoscale mountain on the diurnal cycle of moist convection and its spatial variation is investigated. Convection-resolving simulations of flow over 3D Gaussian-shaped mountains are performed for a conditionally unstable atmosphere under diurnal radiative forcing. The results show considerable spatial variability in terms of timing and amount of convective precipitation. This variability relates to different physical mechanisms responsible for convection initiation in different parts of the domain. During the late morning, the mass convergence from the radiatively driven diurnal upslope flow confronting the large-scale incident background flow triggers strong convective precipitation over the mountain lee slope. As a consequence, instabilities in the boundary layer are swept out by the emerging cold pool in the vicinity of the mountain, and some parts over the mountain near-field receive less rainfall than the far-field. Over the latter, an unperturbed boundary-layer growth allows for sporadic convective initiation. Still, secondary convection triggered over the leading edge of the cold pool spreads some precipitation over the downstream near-field. Detailed analysis of our control simulation provides further explanation of this frequently observed precipitation pattern over mountains and adjacent plains. Sensitivity experiments indicate a significant influence of the mountain height on the precipitation pattern over the domain.

In this paper, the flow in the rectangular fuel cell channel with different aspect ratios has been numerically simulated. The bottom wall of the rectangular channel is porous and subjected to a uniform mass injection or suction, while the other three walls are nonporous or impermeable. Assuming the hydro-dynamically and thermally fully developed flow, the mass, momentum, and energy equations have been solved with a two-dimensional code. The present numerical results are in good agreement with the numerical results in the literature. The wall friction coefficients and Nusselt numbers were obtained for different aspect ratios, different wall Reynolds numbers (for suction and injection), and different thermal boundary conditions. The results show that for each aspect ratio, friction coefficient (fRe) is larger for injection than for suction. Also at unit expect ratio, a/b = 1, the fRe have minimum value for each wall Reynolds number (Rem) and with increasing and decreasing aspect ratio, fRe increases. The changes of Nusselt (Nu) number with Rem and aspect ratio is dependent on the thermal boundary conditions and definition of Nu number (for combined boundary condition). [ABSTRACT FROM AUTHOR]