Vegetation on a floodplain, which contains both emergent vegetation and submerged vegetation, has a considerable influence on the velocity profile of the channel. In this study, a modified analytical model, which considers interactions within the vegetation, is developed based on the Shiono and Knight method (SKM) and the concept of the two-layer model to obtain the transverse distribution of the depth-averaged streamwise velocity in a compound channel with emergent and submerged vegetation. This analytical model includes the influence of secondary flows, lateral shear stress, bed friction, and the drag force caused by the vegetation. The aforementioned model is then employed in a straight compound channel, which contained various types of vegetation. Using suitable boundary conditions, the calculated data are found to be consistent with the experimental data. Subsequently, the effects of dimensionless eddy viscosity coefficient (λ), the depth-averaged secondary flows coefficient, and the impact coefficient β on the model are analyzed. It finds that the λ has a clear effect on the main channel region, but the depth-averaged secondary flows coefficient ($\overline{K}$ ) has only a definite effect in the slope sub-region. The β value is significantly less than 1 for the condition of the vegetation with a variable frontal width. The model proposed in the present work can provide a guidance for the investigation of the flow characteristics of the various vegetated channel.

This study investigates window renovation strategies for a detached building in Belper, UK, analyzing double- and triple-glazed, vacuum, and low-E vacuum windows with varying gas fillings, pillar radii, and spacing. The results reveal that increasing glass layers reduces energy consumption, while a larger pillar radius decreases efficiency. More pillars improve window performance. For windows with the same U-value, a higher SHGC enhances energy efficiency by maximizing solar heat gain, particularly in colder climates. Conversely, reducing the U-value while maintaining a constant SHGC enhances insulation and minimizes heat loss. The study emphasizes the necessity of balancing U-value and SHGC for optimal window performance in different climates. The most effective strategy involves using a low-E vacuum window with a 0.25 mm pillar radius and 40 mm spacing while doubling the south-facing window area, leading to a 7.01 GJ heating load reduction—a 27.9% improvement over modifying the window type alone. Additionally, a key ratio, SHGC/(U_window − U_wall), is introduced to assess window size modifications. The results indicate that enlarging windows is beneficial when solar heat gain surpasses additional heat loss, underscoring the importance of balancing heat conduction and solar energy utilization in energy-efficient building design.

In hydro-driven ship lifts, plunger valves and fixed cone valves are the most suitable structures for achieving accurate flow control under a wide range of flow conditions. In order to inhibit cavitation in these valve structures, experiments were conducted in which forced aeration was applied before the valve. The cavitation phenomena and aerated flow regime were observed through a transparent glass pipe, and the cavitation noise characteristics were recorded using a hydrophone. The test results show that aeration can reduce the valve working cavitation number, albeit to a limited degree (<5%). Based on the sound velocity theory of aerated flow and the experimental results, the relationship between the aeration concentration and the cavitation inhibition efficiency was obtained. When the aeration concentration is approximately 0.1%, cavitation can be significantly inhibited via forced aeration before the valve. Once the aeration concentration reaches 0.9%, the cavitation inhibition efficiency becomes saturated. The research results presented in this paper provide a reference for the cavitation inhibition of industrial valves.

Curved confluent channels are widespread in the Yangtze River basin, and seasonal variation of the main channel width (W1) affects hydrodynamics, sediment deposition, and pollutant dispersal at the confluence zone. To explore the effect of main channel width and flow ratio (q*) on the hydraulic characteristics in the curved confluent channel, the Renormalization Group k–ε turbulence model is employed to conduct a detailed analysis of water surface elevation (WSE), longitudinal velocity distribution, separation zone, and secondary flow. The results indicate that the confluent tributary lowers WSE of the main channel compared to the case without tributary; additionally, the WSE decreases with increasing W1 and increases with increasing q*. As W1 increases, the longitudinal velocity on the inner bank increases, while that on the outer bank decreases in the downstream region of the confluence zone. The scale of the separation zone increases with increase in W1 or q*. The variation of outer bank circulation in the downstream channel of the confluence zone is the most obvious, which decreases with increase in W1 and increases with increase in q*. A formula for solving the secondary flow intensity applicable to confluence channel has been proposed, and the mean secondary flow intensity increases with increase in W1 or q*. The findings of this study not only enhance our understanding of the hydrodynamic characteristics of curved confluence channels but also offer a theoretical foundation for riverbank stabilization and channel management.

Due to the centrifugal force, a spiral flow is formed in a bend, presenting a rotating vortex in the vicinity of the inner bank and another rotating vortex in the opposite direction near the outer bank under certain hydraulic conditions, which have a significant effect on bank erosion processes. The renormalization group k-ε turbulence model was employed to simulate the flows in a U-shaped open channel with various Froude number (Fr). The water level, vertical velocity and secondary flow structure were analysed. The outer bank cell (OBC) has a strong dependence on the Fr and the intensity of the OBC (Q_OBC) firstly increases and then decreases along the channel. The maximum Q_OBC gradually increases and the position of the maximum value first moves downstream and then upstream with the increasing Fr. At the apex of the bend, the nondimensionalize intensity of the OBC first decreases and then increases with the increasing Fr.