Various Angles Of Inclination Research Articles

Molecular dynamics study of nanodroplet impact on superhydrophobic surfaces with varying inclination angles

The dynamic behavior of nanodroplets impacting solid surfaces has significant applications in fields such as anti-icing, self-cleaning, and nanotechnology. However, research on nanodroplet impacts on inclined superhydrophobic surfaces remains limited. In this study, molecular dynamics simulations are employed to systematically investigate the impact of nanodroplets on superhydrophobic surfaces with varying inclination angles. The study reveals the underlying mechanisms of droplet rebound modes, contact time, and sliding distance. The results demonstrate that droplet rebound behavior can be categorized into three modes: regular rebound, cavity rebound, and splashing rebound. The occurrence of these modes is governed by both the Weber number and the surface inclination angle. An analysis of contact time shows a three-phase variation: contact time decreases rapidly at low speeds, remains relatively stable at moderate speeds, and decreases significantly at high speeds. Notably, in the moderate-speed range, the formation of cavity rebound increases contact time, a phenomenon not commonly observed in previous studies on flat surfaces. Additionally, this study derives a theoretical formula for droplet sliding distance based on the Lennard-Jones potential and verifies it through simulations, demonstrating the competition between inertial forces and intermolecular interactions during sliding. The research not only presents a phase diagram of nanodroplet impact outcomes but also contributes novel theoretical insights into contact time and sliding behavior, providing a solid theoretical foundation for optimizing nanodroplet behavior in industrial applications.

Unraveling microstructure characteristics induced mechanical responses in laser welding of titanium alloy subjected to varied inclination angle

The manufacturing of large and intricate components frequently involves spatial curved features, potentially impacting the welded component quality. The differentiation of microstructure morphology distribution is more obvious under different gravity action angles. The paper aims to investigate the microstructure characteristics that influence the mechanical responses in laser welding of titanium alloy plates with varying inclination angles. The weld penetration diminishes with an increase in the inclination angle, while the residual β-columnar crystals decrease as the inclination angle rises. The growth trajectory of β-columnar crystals deviates when the inclination angle is set at 30°. Moreover, specific parameters are incorporated to assess quantitatively the impact of gravity on the depth variations of the keyhole, elucidating the underlying mechanisms governing the macroscopic morphology. The results indicate a decreasing trend in weld depth as the inclination angle increases. In uphill welding, there is a reduction in tensile strength and elongation compared to horizontal laser welding. Fractures in horizontal welding occur in the base material region, demonstrating ductile fracture characteristics, while fractures in uphill welding occur in the weld region, exhibiting quasi-dissolution fracture characteristics.

Robotized Mobile Platform for Non-Destructive Inspection of Aircraft Structures

The robotization of the non-destructive inspection of aircraft is essential for improving the accuracy and duration of performed inspections, being an integral part of inspection and data management systems within the currently developed NDT 4.0 concept. In this paper, the authors presented the design and testing of a universal mobile platform with interchangeable sensing systems for the non-destructive inspection of aircraft structures with various angles of inclination. As a result of the performed studies, a low-cost approach of automation of existing measurement devices used for inspection was proposed. The constructed prototype of the mobile platform was equipped with eddy current testing probe and successfully passed both laboratory and environmental tests, demonstrating its performance in various conditions. The presented approach confirms the effectiveness of the automation of the inspection process using climbing robots and defining the directions of possible development of automation in non-destructive testing in aviation.

Experimental investigation on the mechanism of local scour around a cylindrical coastal pile foundation considering sloping bed conditions

Sea-crossing bridges are often subjected to local scour, significantly impacting the bearing capacity of the foundation system and potentially leading to bridge failures. This study presents experimental investigations of local scour around a cylindrical pile under different sediment slope conditions in unidirectional currents. Unlike previous studies that focused on horizontal sediment beds, this research explores the influence of inclined sediment beds, which reflect coastal and offshore topographies, which have some angles of inclination. Utilizing flume tests, the research investigates the evolution of scour depth, scour range, and the morphology of the sediment bed across various angles of inclination. The study also evaluates the effectiveness of a scour countermeasure involving rip-rap material around the pile on sloping beds. Specifically, a steeper inclination angle induces a faster flow velocity, resulting in increased scour depth at the upstream side of the pile and a reduced scour range at the downstream side due to backfilling. The countermeasure scenario reveals a significant reduction in both scour depth and range. This research provides analysis of the effects of inclined sediment beds, which reflect coastal topographies than horizontal ones, thereby providing insights for the design and protection of bridge foundations in diverse coastal conditions.

Structural optimization and heat-fluid-solid simulation of a graded corundum-calcium hexaluminate purging plug by a multi-objective genetic algorithm approach

The purging plug is essential for enhancing production efficiency in molten steel refining, yet it faces challenges related to structural integrity due to its lifespan often not aligning with the ladle's repair cycle. This study introduces a novel corundum-calcium hexaluminate purging plug with gradual holes designed to alleviate internal stress concentration. Utilizing a multi-objective optimization model and fluid-solid coupling heat transfer method, the impact of structural parameters on thermal and mechanical properties was systematically investigated. The numerical simulation results indicate that increasing the number of gradient layers positively impacts temperature distribution. Notably, the D-210 (1.0 mm diameter) aperture reduces the stress gradient Δσmax by 648.06 MPa compared to D-212 (1.2 mm diameter) at the Y = 0.313 m section. Additionally, variation in inclination angle impacts tensile stress σt and shear stress τ, an inclination angle of 6° (α6) reduces maximum tensile stress by 211.41 MPa compared to an angle of 0° (α0).

Oxidation behavior and oxidation kinetics of film cooling holes at different inclination angles of a Ni-based single-crystal blade

This paper examines the high-temperature oxidation behavior of Ni-based single-crystal turbine blade film cooling holes with varying inclination angles. Utilizing the theory of oxidation kinetics, the concept of an angle influence factor is introduced, and a novel oxidation kinetic equation is formulated. This allows for precise prediction of the oxide/γ′-free layer thickness in film cooling holes across different inclination angles throughout the oxidation process. It offers a new benchmark for future lifespan prediction models, significantly impacting the assessment of the operational life of air-cooled single crystal blades.

Thermo-fluid performance of axially perforated multiple rectangular flow deflector-type baffle plate in an tubular heat exchanger

The study investigated an unconventional heat exchanger design that utilizes swirling airflow to enhance heat transfer over heated tubes. This innovative system incorporates a perforated round baffle plate, accompanied by multiple rectangular air deflectors oriented in opposite directions at varying inclination angles. These deflectors are symmetrically arranged at different pitch ratios alongside consistently spaced tubes forming a circular configuration, all subject to a uniform heat flux. Enclosed within a circular duct with longitudinal airflow, the combined baffle plate and tube assembly bring forth efficient heat transfer. The air-side turbulence intensified by the deflectors induces a chaotic motion, contributing to enhanced surface heat transfer. Each baffle plate has twelve opposite-oriented deflectors, resulting in opposing swirl flows that further promote flow recirculation and augment surface heat transfer. The performance of this heat exchanger was evaluated by considering different pitch ratios and inclination angles across a Reynolds number range of 16000-30000. The findings demonstrate that the heat exchanger with rectangular flow deflectors on the baffle plate exhibits significant improvements in thermo-fluid performance. Notably, an average enhancement of 1.88 was observed at an inclination angle of 50 degrees and a pitch ratio of 1.2 when compared to an exchanger without baffle plates, emphasizing the considerable impact of these design aspects.

Computer aided flow investigation of liquid agricultural wastes

Liquid agricultural wastes serve as important fertilizers in modern agriculture but pose environmental and health risks due to high nitrogen compound content. To prevent soil and groundwater contamination, ammonia separation is required before waste application on fields. Conventional separation by stripping is difficult because of column clogging by solid waste loads. This work investigates, both experimentally and numerically, the flow behaviour of liquid agricultural waste to support the development of innovative separators based on inclined plates. The measurements were carried out in a newly developed experimental setup consisting of a liquid distributor over a plate with variable inclination angles. The influence of volumetric flow rate and inclination angles on the flow topology and liquid detachment from the edge of the plate was studied. While the impact of the flow rate was significant, no influence of the plate inclination angle could be observed. A CFD model was developed to support experimental work. Its validation with experimental data was successful, yet with some systematic deviation due to the model simplifications. The developed experimental setup and CFD model offer optimization potential for separation column internals designed for liquid agricultural wastes, with experiments providing higher accuracy and simulations offering flexibility.

Enhancing heat pipe performance through hybrid wick structures: Balancing pore size and permeability

This study investigates the impact of wick structures on heat pipe performance by optimizing the balance between effective pore radius and permeability for efficient heat dissipation. It addresses the challenge of enhancing capillary pumping forces while maintaining optimal liquid replenishment to the evaporator. A novel hybrid wick structure is proposed, strategically integrating sintered and screened elements within the heat pipe to improve thermal performance. Experimental tests include varying inclination angles (antigravity up to 60°) to assess thermal resistance and liquid return capabilities. Results show a 13.31 % reduction in thermal resistance compared to conventional sintered heat pipes, particularly at higher power levels (40 W– 60 W). At a 40° inclination angle, optimal evaporation and liquid flow improve thermal performance, with thermal resistance for sintered and hybrid heat pipes decreasing by 14.05 % and 27.72 %, respectively. However, at 60° inclination, the hybrid’s thermal resistance increases significantly due to local dry-out. The study identifies limitations beyond 45° inclination, which is attributed to increased receding contact angles, and the influence of gravity becomes more pronounced, affecting capillary limits. This research underscores the importance of innovative wick designs in advancing heat pipe technology for diverse applications.

Model Test Study on the Bearing Mechanism of Inclined Variable Cross-Section Piles Using Transparent Soil

In view of the influence of the inclination and variable section on the pile stability and bearing capacity, this paper introduces particle image velocimetry (PIV) technology, and designs a transparent soil visualization model test. The experimental results show that, when the pile has a variable cross-section and inclination angle, the friction resistance on both sides of the pile increases. The vertical-load-carrying capacity of the 2% and 4% inclined piles with a variable cross-section is greater than that of the piles with inclinations greater than 8%. For model piles with the degrees of inclination of 2% and 4%, the variable-section inclined piles with diameters of 17 mm and 15 mm show significantly less settlement than the equal-section inclined piles. For the model pile with an inclination of 8%, the settlement of the inclined piles with a variable cross-section diameter of 17 mm is slightly smaller than that of the equal cross-section inclined piles. The change in variable cross-section and inclination angle has a large effect on the soil displacement around the pile, and the conclusions of this paper can provide guidance for the engineering application of variable cross-section piles.

Performance investigation of metal foam coupled to phase change material as coolant of photovoltaic concentrator systems: Optimization and electrical efficiency analysis

This research investigates the integration of graphitic metal foam with paraffin RT35HC to manage and reduce the temperature of PV cells, focusing on the rigorous examination of the synergistic effects of metal foam porosity and panel inclination on thermal management. A 2D numerical model was developed using ANSYS Fluent 14.0, where User-Defined Functions (UDFs) were employed to incorporate the Darcy-Brinkman-Forchheimer and Carman-Kozeny equations, accurately accounting for the effects of metal foam porosity on thermal conductivity and fluid flow resistance. Various foam porosities (ε = 0.80, 0.85, 0.90, 0.95, 1) were explored on both vertical and tilted panels across a spectrum of inclination angles (β= 0°, 30°, 45°, 75°, 90°). Results highlight critical parameters including PCM melting fraction, cell temperature evolution, and the resultant impact on solar cell electrical efficiency, both with and without metal foam. The integration of graphitic foam with RT35HC contributed to superior heat transfer and a marked reduction in cell temperature of the employed PV system by improving thermal conductivity and heat dissipation, particularly at slight inclination angles (β =0° to 30°), revealing a noteworthy enhancement in electrical efficiency ranging from 1.3 % to 3 %, respectively. Conversely, the absence of graphitic foam at steeper angles (β =45° to 90°) surprisingly strengthens the solar panel’s electrical performance. These findings provide valuable insights into the effects of metal foam integration at varying inclination angles, offering a pathway for the development of more efficient and reliable solar energy systems.

Determining Stress Intensity Factors at Varied Inclination Angles through Innovative Discontinuous Digital Image Correlation

An innovative method is proposed for determining stress intensity factors at crack tips with different inclination angles, based on the Adaptive Digital Image Correlation (AD-DIC) method. This method involves fitting a set of nonlinear equations with unknown parameters using displacement field data. The initial values for crack tip coordinates and inclination angles, computed through the AD-DIC method, are employed in this process to obtain stress intensity factors at the crack tips. The results demonstrate that this approach accurately captures the crack tip positions and calculates stress intensity factors for cracks at various inclination angles. This addresses the challenge of computing stress intensity factors during the crack propagation stage, where cracks may deviate, making conventional calculations impractical.

Analysis of Stagnation Flow Characteristics in Hybrid Nanofluid Impingement: Velocity Slip, Convective Heat Transfer and Varied Inclination Angles

Analysis of Stagnation Flow Characteristics in Hybrid Nanofluid Impingement: Velocity Slip, Convective Heat Transfer and Varied Inclination Angles

Orientation Dependency of 3D printed SHCC at increasing length scale

In the first part of this study, the inclination-dependent effects on a single fibre embedded in 3D printable strain hardening cementitious composite are studied. Two distinct failure modes (i.e., slipping rupture and complete pull-out) were found in the experimental results. Based on these failure modes two separate slip-hardening factors have been determined and analysed with an analytical fibre pull-out model. The second part of the study focused on the influence of multiple fibres with varying inclination angles on single- and multiple-cracking specimens. These tests have been performed for specimens that were casted and printed, to analyse the effect on ductility due to the extrusion process. Three orthogonal directions were examined within the printed specimens during testing. The amount of energy dissipated during the crack opening is strongly orientation-dependent for 3DP-SHCC and does not significantly increase in the main printing direction compared to casted SHCC. Furthermore, the orientation-dependent ductility is evaluated in bending with the use of a 4PB test. Allowing multiple layers of fibre-reinforced material to become active at the same time. The strain hardening effect found in a single crack is amplified by the material’s capability to develop multiple cracks, ultimately leading to a significant increase in its impact on engineering applications related to bending.

Experimental and numerical study of the three-dimensional temperature field in the arch ribs of the reinforced concrete ribbed arch bridge during construction

The unique structural design of an arch ring featuring varying inclination angles for individual segments causes variations in the longitudinal distribution of the temperature field d along the arch axis. This study aims to enhance the understanding of temperature fields in reinforced concrete (RC) arch bridges with diverse arch ring structural configurations during their construction phases. A comprehensive investigation into the three-dimensional distribution pattern of solar-induced temperature fields within arch ribs during the construction of RC ribbed arch bridges was conducted. A field test specifically measuring the temperature distribution across arch rib cross-sections was conducted on-site, involving an RC arch bridge constructed using the cable-stayed cantilever cast in situ method. Analyzing the monitored on-site temperature data revealed the distribution characteristics of temperature fields at the arch foot cross-section under solar radiation. By comparing these findings with international standards, a vertical temperature gradient fitting model for arch rib cross-sections under solar radiation was formulated. Drawing upon meteorological records and solar radiation principles, an adaptive numerical simulation finite element model was developed to depict the temperature field within an arch rib section. This model was rigorously verified. Subsequently, a comprehensive analysis of the three-dimensional temperature field of the arch rib under solar radiation was performed. Additionally, a three-dimensional temperature gradient fitting model was proposed, accounting for the longitudinal inclination of the bridge.

On the importance of angle-dependent hydrodynamic coefficients in the equilibrium configuration analysis of synthetic fiber towing ropes

The underwater configuration analysis of a towing rope is crucial for estimating the rope tension and the state of the towed body. In the case where the rope inclination angle significantly increases, the partial hydrodynamic force coefficients of a rope segment should display apparent variations with the local inclination angle. However, constant drag coefficients ignoring the angle-dependent drag effect are widely used in numerical studies. To address the importance of the angle-dependent force coefficients for analyzing the underwater configuration of a towing rope, Large Eddy Simulations are carried out to obtain the drag forces of a cylindrical rope segment with varying inclination angles and Reynolds numbers. To model the rope deformation, a tensile experiment is also conducted to establish the nonlinear tension-strain relationship of the fibre rope. Parametric studies are performed to investigate the difference in the results calculated by both constant and angle-dependent hydrodynamic force coefficients. It was found that the application of constant drag coefficients leads to significant underestimation of the rope tension near the towed body, especially when the rope experiences large inclination angles. Therefore, the present study highlights the importance of using the angle-dependent hydrodynamic coefficients to predict the configuration and tension of towing ropes.

Study of the Impact of Varying Inclination Angles of Arch Ribs on the Seismic Behavior of Half-Through Steel Basket-Handle Arch Bridge

In the present study, multiscale finite element (FE) models of half-through steel basket-handle arch bridges were established. The eigenvalue analyses were conducted to explore the dynamic characteristics of the arch bridges based on the FE models. In addition, a parametric analysis was carried out to investigate the impact of the inclination angle of the arch rib (0°, 4°, and 7°) on the longitudinal and transverse seismic performances of arch bridges. The results show that with the increase in inclination angle, the out-of-plane stiffness of half-through steel basket-handle arch bridges increases, resulting in the natural period of the structure becoming shorter from 3.09 s to 2.93 s. Adjusting the inclination angle appropriately has a beneficial impact on the overall seismic performance of the structures, affecting both displacement and internal forces, in which the most significant improvements include a 42.8% decrease in displacement and a 62.6% reduction in internal forces. Adjusting the inclination angle can cause the arch springing and transverse brace to undergo larger plastic deformation. It is advisable to judiciously enlarge the sectional dimensions and enhance the material strength of both the arch springing and the transverse bracing in seismic designs.

Design of a Compact 3-D Vibration-Assisted Turning Device With Large Amplitude and High Frequency for Diversified Microstructure Sculpturing

The 3D vibration-assisted turning (VAT) has attracted increasing attention for its merits in microstructure sculpturing and ultra-precision machining. However, most current 3D VAT tools adopt complex structures and it is still difficult to implement high frequency and large amplitude simultaneously on a simple integrated tool. Here, a 3D VAT tool with high-frequency and large amplitude adjustment capability is proposed for the first time, which adopts a more stable and compact single sandwich piezoelectric transducer structure. High frequency and large amplitude adjustment capabilities improve the machining efficiency and the range of machinable microstructures. The structure of the tool is simplified by using the sandwich-type single transducer structure, which is convenient to reduce cost and improve machining stability. Surface microstructures with variable inclination angles and distribution ratios are firstly sculptured by the proposed 3D VAT tool, which provides a new idea for surface modification. In addition, surface microstructures with different depths and high-precision microgrooves are machined, and better machining results are obtained. The texture depth and machining efficiency of microstructure are increased with the increase of amplitude and frequency. Microgrooves with a surface roughness of Sa 29 nm, minimized burrs and defects, and a specific cutting force reduction of 54.8% are obtained.

Compliance Modeling and Kinetostatic Analysis of a Generalized 3-PSS Compliant Parallel Micro-Motion Platform.

In order to expand the range of motion performance of the 3-PSS-compliant parallel micro-motion platform, a variable inclination angle of the mechanism's guide rails was introduced to construct a category of generalized 3-PSS compliant parallel micro-motion platforms with distinct configurations (exhibiting different motion performances) but identical motion patterns (three translational degrees of freedom). The compliance and kinetostatics of such micro-motion platform are modeled and analyzed. Firstly, the compliance model is established based on the coordinate transformation method. Then, simplifying the micro-motion platform into a spring system, the kinetostatic model in terms of input force-output displacement is established based on the compliance model using the compliance matrix method. For practical application considerations, the kinetostatic model in terms of input displacement-output displacement is further derived based on the input force-output displacement model. Then, the correctness of the established compliance model and kinetostatic model is successively verified through finite element simulation. Finally, using two specified motion trajectories (spatial spiral trajectory and planar circular trajectory) as examples, an analysis is conducted on the influence of guide rail inclination angle variations on the kinetostatic performance of the micro-motion platform. This analysis serves as guidance for the rational design of such micro-motion platforms.

Influence of tilt angles and different models of fluid viscosity on coupled natural convection in a differentially heated closed square cavity with a partition

This article investigates the behavior of various viscosity models under conjugated natural convection in a square cavity with a conductive baffle at various angles of inclination and differential heating of the side walls. Numerical simulations were performed using the finite volume method for a fluid having viscous properties similar to those of a non-Newtonian fluid. The slope angle of the computational domain and the choice of the non-Newtonian fluid model were considered as the main parameters. The inclination of the hull took on the values 0°, 30°, 45°, 60° and 90°. The received data illustrate that the increase in the velocity of convection flows is strongly influenced by the angles of inclination of 30° and 60°. By analyzing various non-Newtonian fluid models, the power low viscosity model predicted velocities more than other viscosity models. Whereas in the Herschel-Bulkley viscosity model, only the heat transfer process mainly occurred. Analysis of the obtained local Nusselt number showed that the values were higher on the cold wall. This is explained by more intense heat transfer due to convection on this wall. It should also be noted from the data obtained that when the region is tilted at α = 90° for the Carreau viscosity model, one can notice the complete absence of the convection process, and when using the Herschel–Bulkley viscosity model, no flow mixing occurred, which led to heat exchange solely due to heat transfer for different tilt angles.