Advances in porous icephobic surfaces: Toward next-generation aircraft ice protection strategy.

Under overland flow with low Reynolds numbers, the resistance parameters generated by the soil and vegetation are crucial under current climate change conditions. The inter-rill erosion occurring under this overland flow can lead to inter-rill erodibility as a resistance parameter, and each type of plant generates different vegetal drag coefficients and hydraulic resistance parameters. A set of sixteen simulated rainfall events capable of generating overland flow on an Fluvisol tilled with a semiarid agroforest, cactus, under a litter layer, and under bare conditions was applied. The overland flows generated were laminar tranquil flows with very low Reynolds numbers varying from 6 to 25 on bare soil. • Environmentally sustainable indicators from soil and semi-arid plants. • Hydraulic resistance and soil erodibility linked to overland flow at low Reynolds number. • Semi-arid crop systems and shrub generating environmental service.

Failure analysis of a centrifugal pump impeller in erosive flow conditions

Numerical study of flow and particle erosion co-evolution in a high-loading compressor cascade

Aeolian sand flow characteristics and erosion mechanism of the disturbed stubble-soil complex after straw harvesting

Abstract This study isolated hydro‐morphodynamic mechanisms leading to mangrove propagule anchoring and seedling dislodgement under erosive flows. Red mangrove ( Rhizophora mangle ) propagules self‐anchored in estuarine sediments over 112 days under simulated tidal pulses. Seedlings were tested under erosive flows at 1 week, 2 weeks, and 1 month after anchoring. One‐month‐old seedlings exhibited notable resistance, withstanding peak velocities of 17–22 cm/s and severe erosion (mean erosion depth 8.3 ± 0.9 cm, volume 1.9 × 104 ± 2.5 × 103 cm 3 ). Seedlings oriented against the flow were more vulnerable to uprooting. Two‐week‐old seedlings oriented with the flow had a greater mean erosion depth (4.4 ± 1.2 cm, p < 0.05) than seedlings oriented upstream (1.5 ± 0.6 cm). Consistent with dislodgement mechanisms proposed in prior studies, the results conformed to three distinct uprooting pathways: instantaneous uprooting by hydrodynamic forces without bed erosion (Type I), removal facilitated by local scour around the roots of seedlings (Type IIa), and removal after large‐scale bed degradation (Type IIb). Erosion depth and volume at the time of dislodgement varied systematically with the geomorphic mechanism of removal. Seedling resistance was closely linked to rooting structure; seedlings uprooted by Type IIb exhibited the longest single root length (mean: 8.6 ± 0.6 cm), highest total root length (mean: 134.4 ± 19 cm), and greatest root volume (mean: 61.1 ± 9.2 cm 3 ).

Comprehensive study on the role of wall roughness in square cyclone performance: Flow field, erosion rate, and separation efficiency

Gas flow erosion behavior and modeling of EPDM insulation material in solid rocket motors

Gas-solid two-phase flow erosion of needle throttle valve in shale gas field based on CFD-DEM model

ABSTRACT Moat–drift contourite systems, formed by interaction of alongslope bottom currents with bathymetric features, provide critical insights into palaeoceanographic changes. However, the role of submarine landslides in their initiation and evolution remains poorly understood. To investigate these processes, this study utilises multibeam bathymetric and three‐dimensional seismic data from the Baiyun Slide, located in the northern South China Sea. The findings reveal a 600‐m‐wide, 50‐m‐deep moat incised along the steep escarpment of the Baiyun Slide headwall, flanked by a ~50‐m‐thick sediment drift. We propose that the landslide‐induced escarpment acted as a bathymetric obstacle, locally intensifying bottom‐current velocities and promoting flow turbulence and erosion, which facilitated moat formation. In contrast, in areas distant from the escarpment, reduced current velocities allowed for deposition of resuspended sediments, forming the drift deposits that fill the slide scar. While the surrounding slope is dominated by gravity‐driven downslope sedimentary processes, the landslide‐generated escarpment reconfigured the local depositional system, enabling the formation of a slide‐controlled secondary contourite system driven by bottom currents. This system, confined within the negative topography of the slide scar, represents a spatial shift in sedimentation from a regional downslope to a localised alongslope control. As a corollary, we present a conceptual model illustrating how submarine landslides can reshape seafloor morphology to drive bottom current‐induced sedimentation in otherwise gravity‐dominated deep‐marine environments. This study highlights slide‐controlled moat–drift contourite systems as significant components of deep‐water sedimentary archives, capable of recording dynamic interactions between bottom currents and seafloor topography.

Abstract. Quantifying erosion across spatial and temporal scales is essential for assessing different controlling mechanisms and their contribution to long-term sediment production. However, the episodic supply of material through landsliding complicates quantifying the impact of the individual erosional mechanisms at the catchment scale. To address this, we combine the results of geomorphic mapping with measurements of cosmogenic 10Be, 26Al, and 14C concentrations in detrital quartz. The sediments were collected in a dense network of nested sub-catchments within the 12 km2-large Gürbe basin that is situated at the northern margin of the Central European Alps of Switzerland. The goal is to quantify the denudation rates, disentangle the contributions of the different erosional mechanisms (landsliding versus overland flow erosion) to the sedimentary budget of the study basin, and to trace the sedimentary material from source to sink. In the Gürbe basin, spatial erosion patterns derived from 10Be and 26Al concentrations indicate two distinct zones: the headwater zone with moderately steep hillslopes dominated by overland flow erosion, with high nuclide concentrations and low denudation rates (∼ 0.1 mm yr−1), and the steeper lower zone shaped by deep-seated landslides. Here lower concentrations correspond to higher denudation rates (up to 0.3 mm yr−1). In addition, 26Al / 10Be ratios in the upper zone align with the surface production ratio of these isotopes (6.75), which is consistent with sediment production through overland flow erosion. In the lower zone, higher 26Al / 10Be ratios of up to 8.8 point towards sediment contribution from greater depths, which characterises the landslide signal. The presence of a knickzone in the river channel at the border between the two zones points to the occurrence of a headward migrating erosional front and supports the interpretation that the basin is undergoing a long-term transient response to post-glacial topographic changes. In this context, erosion rates inferred from 10Be and 26Al isotopes are consistent, suggesting a near-steady, possibly self-organised sediment production regime over the past several thousand years. In such a regime, individual and stochastically operating landslides result in the generation of an aggregated signal that is recorded as a higher average denudation rate by the cosmogenic isotopes. Although in-situ 14C measurements were also conducted, the resulting concentrations are difficult to interpret as soil mixing (due to landsliding), sediment storage or an increase in erosion rates might influence the 14C concentration pattern in a yet non-predictable way.

The double-wall drill pipe reverse circulation converter is a critical component in reverse circulation drilling technology, responsible for switching the flow direction of drilling fluid and transporting rock cuttings. During the reverse circulation drilling process, the drilling fluid carrying cuttings back to the wellhead causes erosion and wear on the converter, which, in severe cases, may lead to complex drilling safety issues. In this study, a finite volume model of the reverse circulation converter was established to systematically investigate its internal flow characteristics and erosion damage mechanisms. The results indicate that the maximum flow velocity and pressure drop in the inner annulus are higher than those in the outer annulus, and significant local throttling effects occur in the diameter-reducing and nozzle channels. Erosion damage is primarily concentrated on the lower inner wall of the converter, particularly in the region opposite the nozzle inlet. This area becomes a structural weak point due to sudden flow path changes, flow direction alterations, and vortex concentration. Sensitivity analysis shows that the erosion rate of the converter increases with drilling fluid flow rate, rate of penetration (ROP), and cutting density, with the sensitivity ranking as follows: drilling fluid flow rate > rate of penetration > cutting density. Therefore, controlling drilling fluid flow rate, optimizing the rate of penetration, and strengthening protection in high-erosion regions are recommended to improve operational safety and service life. This study provides a theoretical basis for erosion protection and structural optimization of double-wall drill pipe reverse circulation converters.

Abstract Bedload transport occurs when the shear stress, or non‐dimensional Shields stress, imparted by a fluid onto a sediment bed exceeds a critical value for sediment entrainment. The history of fluid stress imparted onto a sediment bed influences this critical Shields stress, with bed strengthening occurring under unidirectional flows and bed weakening occurring when the flow direction is reversed. In this study, we examine directional strengthening and weakening in a sediment bed for multiple fluid stress orientations using a rotating bed of sand in a laboratory flume. This sediment bed is exposed to an initial subcritical conditioning flow followed by a subsequent erosive flow at an offset angle of , , , , or . We identify the particle trajectories of a population of sediment grains to measure their velocity, activity, and associated bulk statistics. We confirm bed strengthening (i.e., lower grain velocity and activity) in the unidirectional case, especially for flows at or below the nominal critical Shields stress. As the angular offset increases between the conditioning and erosive flows, both grain velocity and activity increase, with the greatest bed weakening at offsets of and . Our results confirm that stress history is stored anisotropically in the sediment bed, supporting mechanisms such as shear jamming where an anisotropic granular fabric develops in response to shear. These results inform our understanding of how subcritical and critical fluid‐imposed stresses can modify the grain contact and force networks in geophysical contexts.

Abstract Tidal marshes are increasingly recognized for nature‐based shoreline protection. However, their ability to persist under changing environmental and climate conditions remains uncertain, particularly in response to combined stress from hydrodynamic forces (currents, waves) and sediment bed erosion. Conducting flume experiments, we evaluated the resistance of three marsh species ( S. tabernaemontani , B. maritimus and P. australis ), which naturally grow along a cross‐shore gradient from high to low hydrodynamic exposure, to combined stress from water flow and sediment erosion. We reveal distinct functional trade‐offs between above‐ground and below‐ground plant traits: species with flexible above‐ground shoots (here: S. tabernaemontani ) avoid hydrodynamic drag‐induced damage to shoots but are prone to uprooting due to shallow below‐ground root systems, while species with rigid stems and deep roots (here P. australis ) resist uprooting and dislodgement but experience higher hydrodynamic drag forces and hence suffer more from structural stem damage. B. maritimus exhibited intermediate traits, maintaining anchorage with minimal shoot damage, aligning with its occurrence at intermediate positions along hydrodynamic and erosion gradients in the field. These findings demonstrate that plant resistance to physical disturbance in tidal marshes arises from a balance between anchorage and mechanical stress avoidance, driven by variation in functional plant traits. Understanding this balance is crucial for predicting species zonation, persistence and the shoreline protection capacity of tidal marshes. Synthesis and applications . Our study highlights the importance of integrating both above‐ and below‐ground plant traits when assessing marsh resistance. Promoting plant species with complementary stress resistance traits along environmental gradients can enhance the shoreline protection functionality of tidal marshes under changing environmental and climate conditions.

Simulation study on gas-liquid-solid multiphase flow characteristics and erosion mechanism in a natural gas bend

Multiscale modeling of solid-liquid flow erosion in centrifugal slurry pump: A CFD–DEM approach to particle size and hydrodynamic effects

In hydraulic structures such as water control projects, spillway tunnels, and overflow dams that are subjected to high-velocity flow erosion, Concrete is required to exhibit high resistance to abrasion and cracking. While low water-to-binder ratio concrete can meet strength requirements, its inherent high shrinkage propensity often leads to cracking, seriously compromising long-term safety and durability under severe operating conditions. To address this engineering challenge, this study focuses on optimizing concrete performance through the synergistic combination of slag (GGBS) and silica fume (SF). This study systematically investigated the effects of incorporating GGBS (20–24%) and SF (6–10%) in a low water-to-binder ratio system with a fixed 70% cement content on key concrete properties. The evaluation was conducted through comprehensive tests including compressive strength, drying shrinkage, autogenous shrinkage, and hydration heat analysis. The results demonstrate that the blended system successfully achieves a synergistic improvement in both “high strength” and “low cracking risk.” Specifically, the incorporation of silica fume significantly enhances the compressive strength at all ages, providing a solid mechanical foundation for resisting high-velocity flow erosion. More importantly, compared to the pure cement system, the blended system not only delays the onset but also reduces the rate of early-age shrinkage, and lowers its ultimate autogenous shrinkage value. This characteristic is crucial for controlling the combined effects of thermal and shrinkage stresses from the source and preventing early-age cracking. Simultaneously, hydration heat analysis reveals that the blended system retards the heat release process, which helps mitigate the risk of thermal cracking. This study elucidates the regulatory mechanism of the GGBS-SF combination and provides a critical mix design basis and theoretical support for producing high-strength, high-abrasion-resistant, and low-shrinkage concrete in high-velocity flow environments, offering direct practical implications for engineering applications.

The environment-forming importance of medium and small rivers is underestimated by researchers, although these particular ecosystems are highly vulnerable and subject to irreversible technogenic transformation. One of the key factors in the transformation of medium and small steppe rivers in the South of Russia is the regulation of runoff caused by the mass construction of dams. Until now, insufficient attention has been paid to the geomorphological technogenesis of steppe rivers. The aim of the study is to assess the geomorphological consequences of the construction of water-retaining hydraulic structures on typical rivers of the Eastern Azov Region (Kirpili and Ponura). The initial data are materials of airborne laser scanning and digital aerial photography conducted in July–August 2019 (low-water period) along the river beds, as well as field studies. The survey area is 1 333 km2, the density of laser reflection points is 15–20 points/m2. Vectorization of water bodies and analysis of river channel morphology were performed using the constructed DEM with a spatial resolution of 1 m. The relief of river valleys was analyzed using geomorphometry tools using the MaxDifferenceFromMean index. Based on the DEM data, the characteristics of hydraulic structures and ponds were calculated in the GIS environment. The constructed longitudinal profiles have the form of steps (ledges) between water-retaining structures. Thus, in the Kirpili channel, on a section with a length of 217 km, there are 82 blocking structures; dry sections of channels (11 in total) occupy 2.9 km. The total area of ponds formed by the backwater from the damming structures in the Kirpili riverbed is 3 862 hectares with an average pond area of 55 ha. The dismemberment of the riverbed into fragments separated by dams leads to a radical restructuring of geomorphological processes in the river system with a decrease in the morphodynamic activity of the riverbed flow, including deep and lateral erosion. As a consequence of geomorphological technogenesis, the rivers, transformed into a chain of reservoirs, have lost their ecosystem functions.

Wildfires are becoming more frequent all over the world each year. Altered climate and land use patterns are the key causes of unnatural wildfires. They affect terrestrial as well as nearby freshwater ecosystems. After wildfires and consequent removal of forest vegetation, increased water flow and soil erosion amplify the transfer of nutrients, pollutants, and sediment to the freshwater bodies. Water quality of closed lake ecosystems is significantly altered in such circumstances. The present study is an attempt to explore the responses of wildfire on water quality of two inland lakes of Southern Rajasthan, one charred with severe wildfire while another with no recent wildfire incidence. For this purpose, two lakes were seasonally evaluated in terms of water quality responses after the wildfire. They are closed inland freshwater systems with no direct inputs of freshwater other than rainfall. Both the lakes have some resemblance in their sizes, for being less disturbed by direct human activities and having forested catchments, although the topographical and hydrological conditions vary to some extent. Although post-monsoon water quality varies with pre-monsoon conditions due to sediment and mineral transport to lakes with rainwater runoff, fire enhances this impact as vegetation cover is burnt and removed. We observed a range of parameters like pH, TDS, EC, total hardness, alkalinity, nitrate, phosphate, DO, BOD, and DOC in both of the lakes seasonally. The water quality responses were found to have a substantial influence of wildfire in Lake Baghdara. The degree of divergence of impact between the two lakes may be attributed to the presence and severity of wildfire in the catchment of Baghdara Lake. The present investigation will help in analysing the impact of forest fires on closed inland freshwater tropical lakes with forested catchments.

Landscapes are shaped by the interaction of tectonics, climate, and rock erosion dynamics. Active incision in bedrock rivers sets the pace of landscape evolution because river incision cuts deep valleys and canyons into bedrock, transporting that material to the sea. This unburdens Earth's surface, allowing uplift of majestic mountain peaks in tectonically active settings. Bedrock-bound rivers, where the banks and bed are mostly bedrock, are hard points in the landscape that set the upstream base level of drainage basins and that must be vertically incised to lower landscape elevation and balance erosion against tectonic uplift. There are four distinct bedrock-bound channel morphologies that do not occur in alluvial channels—constriction-pool-widenings, rapids, overfalls, and waterfalls—each of which has a distinct flow structure. Our ability to predict bedrock-bound channel morphodynamics is nascent, but the discovery of mechanistic lateral bedrock erosion models, coupled with existing vertical incision models, allow prediction of bedrock river geometry and adjustments due to changes in water flux, sediment supply, and regional uplift. ▪ Coupled lateral and vertical erosion models reveal that the geometry of bedrock rivers is dominantly controlled by sediment supply, not discharge. ▪ Coupling observations of nonuniform flow structures and erosion models confirm that bedrock-bound channels are loci of intense erosion along a river's profile. ▪ Prediction of the 3D shape of bedrock-bound rivers is possible by combining models for flow, sediment transport, and bedrock erosion. ▪ Morphodynamic predictions are limited by poor understanding of nonuniform flow structures, flow resistance, and sediment transport in bedrock-bound channels.