Search Results (1,167)

The dynamic behavior of pipelines subjected to additional masses is crucial for optimizing the design and reliability of engineering systems, particularly in offshore and industrial applications. This study investigates the effect of slenderness on the dynamic response of a pipe with one or more additional masses placed at different positions along its length, considering the symmetry of the system in mass distribution. The aim is to analyze how mass placement influences vibration characteristics under fluid–structure interaction (FSI) conditions. The pipe is modeled as a Rayleigh beam, and the governing equations of motion are derived using Hamilton’s principle while preserving the inherent symmetry of the system. A non-dimensionalized approach is employed to ensure broad applicability across different geometric and material configurations. The vibration frequencies are obtained using the Galerkin method (GM) and validated via a two-way FSI technique, integrating computational fluid dynamics (CFDs) and structural mechanics using ANSYS 2022 software. The results demonstrate the relationship between the concentrated mass ratio and vibration frequency for the first three modes, highlighting the influence of slenderness ratio on system stability. These findings provide valuable insights for the engineering design of pipeline systems subjected to dynamic loading. Full article

We employed the nonlinear finite element software ANSYS LS-DYNA 19.0 to develop a coupled dynamic-static load model for shale oil reservoirs in the Qianjiang Depression through theoretical analysis and numerical simulation and to investigate an oil extraction technology by improving oil yield while maintaining environmental sustainability of Qianjiang Depression. The effects of various loading conditions, including hole size and different oxygen balance of explosives, on oil recovery efficiency during reservoir rock blasting are extensively examined. Numerical simulations reveal that NTNMT explosions transfer more energy to the reservoir rock, compared to DEGDN and TNT. Specifically, when the charging radius is set to 6 cm, NTNMT yields optimal fracture expansion and coalescence, leading to improved economic benefits for shale oil extraction. Additionally, density functional theory (DFT) simulations were conducted to analyze the decomposition processes of different oxygen balance explosive molecules within the reservoir and assess their potential pollution. The results indicate that all the explosives can degrade reservoir rocks, but the explosion of positive oxygen balance, NTNMT, exhibits the highest degradability and lowest environmental impact. Full article

Based on a reduced model of a linear section of a steel gas pipeline between four supports and with a crack-like through defect, ANSYS FE software is used in this study to develop numerical approaches regarding three key parameters of a composite bandage in the form of a circular lining: the type of composite material and the length and thickness of the composite lining. The approach for assessing the static strength of a damaged section of a steel pipeline with a composite lining that is subjected to internal pressure allows for the determination of the optimal thickness of the composite lining itself, which is equal to the indicator “50.0% to 62.5%” of the pipe thickness. Furthermore, the approach for assessing the dynamic strength and analyzing the possible destruction of the reinforced damaged section of a pipeline experiencing an increase in internal pressure allows for the determination of the optimal length of the composite lining, which, in turn, should be at least 241.2 mm. This work also considers cases when there is no internal pressure and the steel pipeline is subjected to critical pressure. It is found that the frequency spectrum of pipeline oscillations without a composite lining is higher than that with a composite lining. The difference between the corresponding dynamic oscillations increases with the thickness or the length of the composite lining. In the absence of internal pressure, all frequencies of the steel pipeline with a crack closed by a composite lining are paired. This pairing is disrupted when the pipeline is subjected to critical internal pressure, and the difference between its oscillation frequency spectrum without and with a composite lining increases. In this case, the oscillation modes significantly differ from those of the same pipeline structure when unloaded. The results ensure the optimal stress distribution in the defect area of a steel pipeline wall and improve the reliability and safety of pipelines under seismic actions. The approach for increasing dynamic strength and eliminating defects can be applied to pipelines with a large diameter regardless of the causes and geometric dimensions of the defects. Moreover, this approach to increasing the strength can be used by various industries and/or institutes which work on the design of new, earthquake-resistant, reinforced pipelines. Full article

This research seeks to investigate the viability of using Tectona grandis wood powder as a reinforcement material in polymer matrix composites because of the increasing awareness of natural fibers that offer impressive characteristics and cost-effectiveness in addition to being biodegradable. The fibers were mixed with epoxy resin, and the mixture was passed through a filter to remove fiber bundles and then compression molded to form composites, which were cured in an oven. Different experiments were performed on the composite to measure its mechanical characteristics. The tests performed were a tensile test to measure the mechanical properties of the material like strength and elastic properties, a compression test for evaluating the behavior of the material under a compressive load, a hardness test for the rate of indentation resistivity, and an impact test for the material’s ability to withstand shock loads. The results showed that fiber reinforcement caused a significant enhancement in the mechanical aspect of the composite, where the compression strength obtained was 249.83 MPa, and the tensile strength obtained was 17.98 MPa. SEM microstructural analysis and a moisture absorption test were performed, while an additional analysis was carried out using Ansys work bench software. This research proves that Tectona grandis wood powder improves the mechanical properties of polymer composites and represents a viable substitute for synthetic reinforcements. Full article

Currently, the existing high-pressure water mist fire protection systems in cold storage facilities face challenges in achieving efficient atomization and uniform water mist distribution, which may limit their effectiveness in rapid cooling and flame suppression. The objective of this investigation is to improve the performance of high-pressure fine water mist nozzles by integrating a Venturi microbubble generator to improve mist atomization and distribution, particularly in the context of flames involving combustible polyurethane foam insulation materials. The gas–liquid two-phase flow characteristics within Venturi tubes were investigated through numerical simulations using ANSYS-Fluent 2022 R1 software. This study focused on critical parameters, including the water inlet pressure (1–9 MPa), pharynx diameter (8–12 mm), contraction angle (15–45°), and expansion angle (15–45°). The average water mist droplet diameters at 1, 3, and 9 MPa were 169.890, 150.002, and 115.606 μm, respectively, in the absence of the Venturi tube, according to the experimental results. A reduction of up to 16.7% was achieved by reducing the particulate sizes to 141.462, 139.142, and 109.525 μm using the Venturi tube. The fire-extinguishing time and water consumption were substantially reduced at higher pressures, such as 9 MPa. Under high-pressure conditions, the results indicated that the Venturi microbubble technology was significantly more effective in suppressing fires. The novelty of this study lies in the application of Venturi microbubble technology to improve fine water mist systems for fire protection in cold storage facilities. This enhanced system achieves better atomization, uniform water mist distribution, faster cooling, and more efficient flame suppression, making it a viable solution for improving fire protection in such environments. Full article

The hydrocarbon liquid rocket engine working environment is harsh; the thrust chamber needs to withstand high temperatures and a high-pressure working environment, and the thrust chamber wall material is difficult to bear, so it is necessary to design the cooling structure to reduce the gas damage to the chamber wall. Liquid film cooling is a common cooling method for hydrocarbon rocket engines, and numerical simulation is an important method for studying liquid film cooling. Most of the liquid film cooling numerical simulation is for a fixed model. This paper proposes a liquid film cooling numerical calculation method for a variable-configuration hydrocarbon liquid rocket engine, based on the secondary development of Fluent software (ANSYS Fluent 2022) to form a high-energy hydrocarbon liquid rocket engine design software, which can be realized on the Qt platform. The visualization interface can be for different engine injection port locations, numbers, angles, mass flow rates, and other parameters, to calculate and improve design efficiency and reduce operating difficulty. Full article

Thermal barrier coating can effectively reduce the temperature of engine piston substrates. However, traditional YSZ coating materials are prone to sintering under high-temperature conditions, resulting in coating failure. To address this issue, finite element simulation of a type of new coating was conducted. Gd₂Zr₂O₇ (GZO), a material with strong anti-sintering properties, was selected as a potential candidate for the design of a dual-ceramic layer thermal barrier coating. A GZO/YSZ-coated piston of a diesel engine was designed, and its mechanical/thermal behavior was simulated by a finite element model. A piston surface temperature experiment was conducted to validate the finite element model. The temperature and the thermal stress of the GZO/YSZ dual-ceramic layer coated piston were analyzed by finite element simulation software ANSYS 2023. The results showed that the GZO/YSZ dual-ceramic layer coating effectively reduced the substrate temperature and showed potential for improving the thermal efficiency of the engine. However, due to the properties of GZO and the structure of the coating, the surface stress of the GZO/YSZ dual-ceramic layer coating was relatively high, requiring further studies to verify its reliability. Full article

This work aims to study the dynamic aspects related to mechanical vibrations, focusing on vibrational analysis and harmonics concerning safety and maximum efforts supported by operators working with dynamic mechanical equipment. The main goal is the determination of resonance vibrations, displacements, and accelerations at the workstation of a crane operator. A modal and harmonic analysis was performed using the finite element method and the ANSYS software 2022 R1. The findings indicated that the primary vibration modes impacting the operator’s well-being occurred at 1, 2, and 8 Hz, potentially inducing pronounced resonance phenomena in the operator’s head, torso, and feet areas. Nevertheless, other vibration modes are less relevant within the vibrational context, and they should be avoided due to the resonance phenomenon in the system. It was found that the displacements in the crane seat were of the order of 1.4 mm, and the maximum vibration acceleration was 5.48 m/s². Full article

The double-bearing vortex pump is a new type of high-efficiency vortex pump. Compared with the traditional vortex pump, its volume and mass are significantly reduced, and its reliability is greatly improved. As the core component of the pump, the impeller has a decisive impact on the overall performance of the pump. Therefore, in order to deeply understand the internal flow mechanism of the vortex pump and improve its hydraulic performance. The mesh model of the double-bearing vortex pump is established by using UG 12.0 and ANSYS Fluent 2022 R1 software, and the influence of different rotational speeds on the flow field characteristics, such as fluid velocity and pressure in the internal vortex pump, is analyzed. The accuracy of the numerical simulation results is verified through experiments. On this basis, the impeller structure of the vortex pump is optimized by introducing the orthogonal design method and taking the impeller diameter, blade groove radius, blade number, and impeller width as optimization parameters. The results indicate that the number of blades is the most critical factor affecting the performance of vortex pumps, and the optimized impeller design increases the head and efficiency of the vortex pump by 18.9% and 11.6%, respectively. This provides important reference for improving the structural design of vortex pump impellers and enhancing their hydraulic performance. Full article

The current work includes experimental and numerical investigations into the effects of biodiesel (Eichhornia Crassipes) blends with different aluminum oxide nanoparticle concentrations on the combustion process in diesel engines. The experiments included measuring performance parameters and emissions tests while changing the engine speed and increasing loads. IC Engine Fluent, a specialist computational tool included in the ANSYS software (R19.0 version), was used to simulate internal combustion engine dynamics and combustion processes. All investigations were carried out using biodiesel blends with three concentrations of Al₂O₃ nanoparticles: 50, 100, and 150 ppm. The tested samples are called D100, D80B20, D80B20N50, D80B20N100, and D80B20N150, accordingly. The combustion characteristics are improved due to the catalytic effect and higher surface area of nano additives. The results showed improvements in the combustion process as the result of the nanoparticles’ addition, which led to the higher peak cylinder pressure. The increases in the peak cylinder pressures for D80B20N50, D80B20N100, and D80B20N150 about D80B20 were 3%, 5%, and 8%, respectively, at a load of 200 Nm, while the simulation found that the maximum temperature for biodiesel blends diesel was higher than that for pure diesel; this was due to the higher hydrocarbon values of D80B20. Also, nano additives caused a decrease in temperatures in the combustion of biofuels. Finally, nano additives caused an enhancement of the emissions test results for all parameters when compared to pure diesel fuel and biofuel. Full article

This research article outlines our aim to perform topology optimization (TO) by reducing the mass of the connecting rod of an internal combustion engine based on static structural and dynamic analyses. The basic components of an internal combustion engine like the connecting rods, pistons, crankshaft, and cylinder liners were designed using Autodesk Inventor Professional 2025. Using topology optimization, we aimed to achieve lesser maximum von Mises stress during static structural analysis and maintain a factor of safety (FOS) above 2.5 during rigid body dynamics. A force of 64,500 N was applied at the small end of the connecting rod while the big end was fixed. Topology optimization was carried out using ANSYS Discovery software at various percentages on a trial-and-error basis to determine better topology with lesser maximum von Mises stress. Target reduction was set to 4%, and as a result, 5.66% mass reduction from the original design and 6.25% reduced maximum von Mises stress was achieved. Later, transient analysis was carried out to evaluate the irregular motion loads and moments acting on the connecting rod at 1000 rpm. The results showed that the FOS remained above 2.5. Finally, the optimized connecting rod was simulated and verified for longevity using Goodman fatigue life analysis. Full article

Four kinds of silicone hydrogel transparent contact lenses (CLs) with different formulations were prepared by the free radical photocuring polymerization. By mixing polyethylene glycol diacrylate (PEGDA) of 1000 Da with ethylene glycol dimethacrylate (EGDMA) and adding other silicone monomers and hydrophilic monomers, the transparency and flexibility of the material were successfully achieved. By optimizing the weight percentage of each component, the best balance of optical performance can be achieved. The photocuring properties of the materials were characterized by electronic universal test, double-beam UV-visible spectrophotometer, Atomic Force Microscope (AFM), Scanning Electron Microscope (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The results showed that the addition of higher PEGDA content reduces the elastic modulus, improves curing efficiency, improves equilibrium water content (EWC), and enhances light transmission. Hydrogels containing only high PEGDA but no EGDMA showed similar curing rates, water content, and elastic modulus, but had the worst optical transparency, far inferior to the materials mixed with PEGDA and EGDMA. Additionally, imaging performance of the CLs was further evaluated through simulation analysis using Ansys Zemax OpticStudio2024 software. This research provides a new choice of material consideration to improve the performance and wearing comfort of CLs. Full article

In order to gain a deeper understanding of the distribution of residual stresses in swing-arc narrow-gap GMA welding, this paper comprehensively considers the arc motion trajectory and joint geometry and establishes a three-dimensional finite element numerical analysis model for residual stresses based on elastic–plastic theory. Using the Ansys software, the welding residual stresses were calculated under swing frequencies of 4 Hz, 3 Hz, and 2 Hz, and the distribution characteristics of residual stresses were analyzed. The results indicate that the model effectively and accurately represents the movement trajectory and distribution characteristics of the swing arc. Furthermore, the calculated temperature field and residual stress outcomes align closely with the experimental findings, thereby validating the accuracy of the model. Under varying swing frequencies, the distribution patterns of residual stress along each sampling line exhibit a consistent similarity. The residual stress is predominantly concentrated in the weld zone and the adjacent heat-affected zone, while it remains relatively low in areas further away from the weld. As the swing frequency increases, the residual stress decreases. The reason for this is that an increase in swing frequency can lead to a more uniform distribution of arc heat within the weld bead, ultimately resulting in lower residual stress. Full article

Despite the numerous benefits of high-temperature superconducting (HTS) power transformers, they are highly sensitive and vulnerable from a thermal perspective, particularly under fault current conditions due to their fault current tolerance properties. Ensuring the proper operation of the cooling system can enhance the transformer’s performance during fault and overload conditions. To improve the thermal management of this transformer in both convective heat transfer and nucleate boiling conditions, utilizing liquid nitrogen (LN₂) nanofluid instead of conventional LN₂ is a promising solution. In this study, a two-phase Eulerian model using ANSYS Fluent software is employed to analyze the impact of different volume fractions (VFs) of Al₂O₃ nanoparticles with a 40 nm diameter on the cooling performance of a power HTS transformer. The numerical simulations are conducted using the Ranz–Marshal method for heat transfer and the finite element method for solving the governing equations. Nanoparticle concentrations ranging from 0 to 1% are evaluated under various fault conditions. Additionally, the influence of nanoparticles on bubble behavior is examined, partially mitigating the blockage of cooler microchannels. The simulation reveals that adding nanoparticles to the fluid reduces the temperature of the hotspot by 29% in steady state and by 34–52% under different fault currents as a result of 0–46% enhancement of nucleate boiling heat transfer, thereby improving the cooling efficiency of the transformer. Full article

The cooling system plays an essential role in regulating the temperature of hybrid vehicle engines. With the contemporary surge in the number of hybrid vehicles, the cooling system’s performance is vital for the safe and stable operation of these cars. The radiator, as the core component of the cooling system, has become central to enhancing thermal efficiency through performance optimization. Improvements to existing radiators are especially important in order to meet increasing performance demands. This paper firstly outlines the development of radiator technology for hybrid vehicles both domestically and internationally; it then analyzes the tube and belt radiator, and selects a louvered finned radiator with highly efficient heat dissipation performance as the object of research. It then carries out the detailed design and assessment of the radiator, formulates an accurate design scheme, and creates a three-dimensional model of the radiator and its main parts using the CATIA V5 software. Finally, the simulation and analysis Fluent software (ANSYS 2023 R1) is used to carry out a comparative analysis of the designed radiator and its important parts. The study focuses on how fin angle, inlet and outlet positioning, radiator orientation, and fan speed affect thermal performance. The findings indicate that a 26° fin angle, a same-side inlet and outlet layout, correct radiator orientation, and higher fan speeds enhance cooling efficiency. These optimizations improve radiator performance, ensuring efficient cooling under various operating conditions. Full article