In the inclined layer convection system, thermal convection in a Rayleigh–Bénard cell tilted against gravity, the flow is subject to competing buoyancy and shear forces. For varying inclination angle ($\gamma$) and Rayleigh number ($ \textit{Ra}$), a variety of spatio-temporal patterns is observed. We investigate the switching diamond panes (SDP) pattern, observed at $(\gamma , \textit{Ra})\simeq (100^\circ ,10\,000)$, which exhibits large-scale oblique features and is one of the five complex tertiary patterns at Prandtl number $ \textit{Pr}=1.07$. First, we study the linear instability of the secondary-state transverse convection rolls and the five branches including two travelling waves and three periodic orbits, bifurcating simultaneously from it. These non-generic bifurcations arise from the breaking of specific spatial symmetries of transverse rolls, and the resulting bifurcated solutions show large-scale diamond-shaped amplitude modulations. Second, we explore a periodic orbit that captures both the large-scale structure and small-scale defects of modulated rolls. Parametric continuation in $ \textit{Ra}$ reveals the global homoclinic bifurcation via which this periodic orbit emerges. Third, the edge states between two dynamically relevant periodic orbits have been computed. Specifically, additional steady and time-periodic solutions are identified on the basin boundary and their bifurcation structures are analysed. Together, using nonlinear invariant solutions and their bifurcations, we take a further step toward understanding the emergence and dynamics of SDP far from the onset of convection, where linear methods have not been applied successfully.

Direct numerical simulations are performed to elucidate the influence of counter- and co-rotation on turbulent viscoelastic Taylor–Couette flow in the Rossby number range $ \textit{Ro}^{-1}=-0.6$ to $ \textit{Ro}^{-1}=1$. A novel polymer-induced transition pathway is discovered that is fundamentally different from Newtonian flows. In the counter-rotation regime, the neutral surface is elastically modified and separates the turbulent inner-wall region containing chaotic vortices from the relaminarised layer adjacent to the outer cylinder. Strikingly, co-rotation triggers an elasto-rotational instability, which leads to the breakdown of large-scale Taylor vortices into small-scale penetrating structures, thereby preventing the relaminarisation at high co-rotation rates. Examination of turbulence dynamics demonstrates that the structural changes with increasing $ \textit{Ro}^{-1}$ are accompanied by a transition from elasto-inertial to elastically dominated turbulence. Specifically, the polymer stress progressively exceeds the Reynolds stress and monotonically enhances angular momentum transport, which eliminates the optimal transport characteristic found in the Newtonian flow. The elastically dominated nature of the turbulent flow under co-rotation is further corroborated by the more significant elastic production of the turbulent kinetic energy, as well as the monotonic enhancement of the polymer elongation as $ \textit{Ro}^{-1}$ increases. Furthermore, it is indicated that the polymer orientation strongly depends on vortical structures, with enhanced radial alignment occurring in the boundary region between adjacent vortices. This vortex-mediated polymer orientation is crucial for generating substantial polymer shear stress, establishing a direct link between coherent structures and polymer dynamics.

The growth of a single vapour bubble in a saturated pool of boiling water at atmospheric pressure on a transparent heater is investigated experimentally. The study focuses on a several microns thick liquid layer (called a microlayer) that can form between the heater and the bubble. The microlayer profile, the wall temperature distribution and the overall bubble shape are measured simultaneously and synchronously by white light interferometry, infrared thermography and sidewise shadowgraphy. To study the microlayer dynamics for different bubble growth rates, artificial cavities of different sizes were used. These control the wall superheating required for the bubble nucleation, i.e. the nucleation barrier. Both the bubble growth at its inertial stage and the microlayer parameters are found to be almost independent of the applied heat flux and controlled by the nucleation barrier only. The microlayer thickness and its area increase with the nucleation barrier. A model of microlayer formation based on an analogy with the Landau–Levich film deposition is further developed. By using it, the initial microlayer thickness, the time of microlayer formation at a given distance from the bubble centre and the radius of curvature of the bubble foot edge are recovered from the experimental data. The radius of curvature varies in time like the bubble radius, thus suggesting a self-similar bubble growth at its initial inertial stage. The coherency of the above model with the experimental results shows the model’s validity.

Subterranean environments are distributed across diverse environmental and geographical landscapes. In this study, we assume that cave occurrences areas in Brazil occupy a multidimensional large-scale space and apply a site selection model that integrates environmental and geographical factors to identify distinct locations for speleological studies. Our approach combines these findings with existing knowledge on the distribution of Brazilian caves. The results reveal 45 unique environmental-geographic sites across five biomes and 19 Brazilian states. Our findings show that when both geographical and environmental heterogeneity are considered, the current knowledge of cave distribution in Brazil remains fragmentary, with particularly evident gaps in the Cerrado, Amazon rainforest, and Caatinga Biomes. These deficiencies almost certainly extend to the documentation of subterranean biodiversity. Most of the sites highlighted by the model contain few or no recorded caves in their surroundings, emphasizing the urgent need for systematic prospecting and biodiversity surveys in these underrepresented regions. Moreover, the lack of a publicly accessible, standardized database compiling primary records of cave biodiversity represents a major limitation for large-scale analyses. This shortcoming likely contributes to the repeated documentation of species within a narrow set of geographical and environmental contexts, thereby restricting comprehensive assessments of subterranean biodiversity across Brazil.