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Records with Type: Published Article
570. LAPSE:2024.1861
Economic Optimization of Thermal Insulation Thickness for Insulated and Electrically Traced Pipelines in Drilling Applications
August 23, 2024 (v1)
Subject: Environment
Keywords: electric heat tracing pipes, insulation pipes, insulation thickness optimization.
This study presents an economic optimization model for determining the optimal insulation thickness for both thermal insulation and electric tracing pipelines. Using Life-Cycle Cost (LCC) analysis, optimization research was conducted under various working conditions to identify the most cost-effective insulation thickness. Factors such as pipe diameter, operational duration, drilling fluid temperature, and heat cost were analyzed to assess their impact on the economic thickness of the insulation layer, specifically within the unique environment of drilling sites. The results provide the economic thickness and total cost for both insulated and electrically traced pipelines under different scenarios. For instance, for a DN100 pipe with rock wool insulation operating for 3600 h, the economic thickness of the electrically traced pipe insulation was determined to be 5.18 cm greater per unit length compared to the non-electrically traced pipe, resulting in an additional cost of 19.36 CNY/m.... [more]
571. LAPSE:2024.1860
Classification Model for Real-Time Monitoring of Machining Status of Turned Workpieces
August 23, 2024 (v1)
Subject: Process Monitoring
Keywords: Bidirectional Long Short-Term Memory, deep learning, denoising autoencoders, state recognition, tool chatter, turning.
The occurrence of tool chatter can have a detrimental impact on the quality of the workpiece. In order to improve surface quality, machining stability, and reduce tool wear cycles, it is essential to monitor the workpiece machining process in real time during the turning process. This paper presents a tool chatter state recognition model based on a denoising autoencoder (DAE) for feature dimensionality reduction and a bidirectional long short-term memory (BiLSTM) network. This study examines the feature dimensionality reduction method of the DAE, whereby the reduced-dimensional data are concatenated and input into the BiLSTM model for training. This approach reduces the learning difficulty of the network and enhances its anti-interference capability. Turning experiments were conducted on a SK50P lathe to collect the dataset for model performance validation. The experimental results and analysis indicate that the proposed DAE-BiLSTM model outperforms other models in terms of prediction... [more]
572. LAPSE:2024.1859
Dynamic Change Characteristics and Main Controlling Factors of Pore Gas and Water in Tight Reservoir of Yan’an Gas Field in Ordos Basin
August 23, 2024 (v1)
Subject: Process Control
Keywords: absorption of water vapor, gas–water distribution, nuclear magnetic resonance, tight reservoir, water saturation, Yan’an gas field.
Tight sandstone gas has become an important field of natural gas development in China. The tight sandstone gas resources of Yan’an gas field in Ordos Basin have made great progress. However, due to the complex gas−water relationship, its exploration and development have been seriously restricted. The occurrence state of water molecules in tight reservoirs, the dynamic change characteristics of gas−water two-phase seepage and its main controlling factors are still unclear. In this paper, the water-occurrence state, gas−water two-phase fluid distribution and dynamic change characteristics of different types of tight reservoir rock samples in Yan’an gas field were studied by means of water vapor isothermal adsorption experiment and nuclear magnetic resonance methane flooding experiment, and the main controlling factors were discussed. The results show that water molecules in different types of tight reservoirs mainly occur in clay minerals and their main participation is in the formation... [more]
573. LAPSE:2024.1858
Catalytic Biomass Transformation to Hydrocarbons under Supercritical Conditions over Nickel Supported on Schungite
August 23, 2024 (v1)
Subject: Energy Systems
Keywords: deoxygenation, green diesel, Ni-catalyst, schungite support, stearic acid.
Liquid fuel production from biomass-derived molecules has received great attention due to the diminished fossil fuel reserves, growing energy demand, and the necessity of CO2 emission reduction. The deoxygenation of oils and fatty acids is a promising process to obtain “green” diesel. Herein, we report the results of the study of the deoxygenation of stearic acid to alkanes as a model reaction. Series of Ni-supported on schungite were obtained by precipitation in subcritical water (hydrothermal deposition) and for comparison via wetness impregnation followed, in both cases, by calcination at 500 °C and a reduction in H2 at 300 °C. The catalyst obtained via hydrothermal synthesis showed a three-fold higher specific surface area with a four-fold higher active phase dispersion compared to the catalysts synthesized via conventional impregnation. The catalysts were tested in stearic acid deoxygenation in supercritical n-hexane as the solvent. Under optimized process conditions (temperature... [more]
574. LAPSE:2024.1857
Development and Characterization of a Novel Microwave Plasma Source for Enhanced Healing in Wound Treatment
August 23, 2024 (v1)
Subject: Biosystems
Keywords: argon plasma, cold atmospheric plasma, microwave plasma, microwave plasma, plasma device, tissue regeneration, wound care, wound healing, wound regeneration.
Our study explores the potential of a novel microwave plasma source for enhancing wound healing in BALB-C mouse models. Chronic wounds, particularly in diabetic individuals, present significant challenges due to impaired regenerative capacity. Cold Atmospheric Plasma (CAP) has emerged as a promising approach, offering diverse therapeutic benefits. However, its specific efficacy in the context of diabetic wounds remains underexplored. We developed and characterized a microwave plasma source optimized for wound treatment, inducing acute wounds and treating them with CAP in a controlled experimental setup. The treated group exhibited accelerated wound closure compared to controls, suggesting CAP’s potential to enhance the healing process. Our findings underscore CAP’s multifaceted impact on the wound healing cascade, highlighting its ability to promote angiogenesis, modulate inflammatory responses, and exhibit antimicrobial properties. These results position CAP as a promising interventio... [more]
575. LAPSE:2024.1856
Application of Principal Component Analysis for the Elucidation of Operational Features for Pervaporation Desalination Performance of PVA-Based TFC Membrane
August 23, 2024 (v1)
Subject: Numerical Methods and Statistics
Keywords: operational features, pervaporation desalination, principal component analysis, PVA-based TFC membrane.
Principal Component Analysis (PCA) serves as a valuable tool for analyzing membrane processes, offering insights into complex datasets, identifying crucial factors influencing membrane performance, aiding in design and optimization, and facilitating monitoring and fault diagnosis. In this study, PCA is applied to understand operational features affecting pervaporation desalination performance of PVA-based TFC membranes. PCA-biplot representation reveals that the first two principal components (PCs) accounted for 62.34% of the total variance, with normalized permeation with selective layer thickness (Pnorm), water permeation flux (P), and operational temperature (T) contributing significantly to PC1, while salt rejection dominates PC2. Membrane clustering indicates distinct influences, with membranes grouped based on correlation with operational factors. Excluding outliers increases total variance to 74.15%, showing altered membrane arrangements. Interestingly, the adopted strategy show... [more]
576. LAPSE:2024.1855
Effect of Nozzle Quantity on the Flow Field Characteristics and Grinding Efficiency in a Steam Jet Mill
August 23, 2024 (v1)
Subject: Modelling and Simulations
Keywords: fly ash, grinding efficiency, nozzle quantity, numerical simulation, steam jet mill.
A steam jet mill (SJM), which employs industrial waste heat steam as a gas source, is a widely utilized apparatus for the pulverization of fly ash. To achieve elevated single-machine grinding capacity, efficiency improvement research based on structural optimization should be conducted. In this study, numerical simulations and industrial experiments are carried out on SJMs equipped with three and six nozzles (hereinafter referred to as N3 and N6, respectively) to study the influence of nozzle quantity on the flow field and grinding efficiency. The numerical simulation results indicate that, under the N3 structure, particles can achieve a higher impact velocity in the comminution area and improve the kinetic energy of a single impact. In the conveying area, the airflow diffusion is better, resulting in an upward flow field that is more uniform. The classification area shows an increase in the uniformity of the flow field and a significant reduction in the local vortex structure, which i... [more]
577. LAPSE:2024.1854
Productivity Model Study of Water-Bearing Tight Gas Reservoirs Considering Micro- to Nano-Scale Effects
August 23, 2024 (v1)
Subject: Energy Systems
Keywords: fractal theory, micro- and nano-effects, productivity, relative gas–water permeability, tight sandstone.
Tight sandstone is rich in micron- and nano-scale pores, making the two-phase flow of gas and water complex. Establishing reliable relative permeability and productivity models is an urgent issue. In this study, we first used a slip model to correct the gas phase’s no-slip Hagen−Poiseuille equation for nano- and micropores. Then, combined with the fractal theory of porous media and the tortuous capillary bundle model, we established two-phase relative permeability models for nanopores and micropores. These relative permeability models comprehensively consider the gas slippage effect, the initiation pressure gradient, the pores’ fractal characteristics, and water film mechanisms. Based on these models, we developed a three-region coupling productivity model for water-bearing tight gas reservoirs with multi-stage fractured horizontal wells. This productivity model considered the micro- and nano-scale effects and the heterogeneity of fracture networks. Then, the model was solved and valid... [more]
578. LAPSE:2024.1853
Morphological and Structural Characterization of Encapsulated Arginine Systems for Dietary Inclusion in Ruminants
August 23, 2024 (v1)
Subject: Materials
Keywords: arginine, carnauba wax, encapsulation, Eudragit®, in vitro degradability, microcapsules, microcrystals, rumen.
This research evaluated two methods of arginine encapsulation, melt emulsification and nanoprecipitation, using a lipid matrix of carnauba wax and commercial polymers (Eudragit®) as a protective material. The ratios of wax−arginine were 1:1, 2:1, 3:1, and 4:1, while those of Eudragit® RS:RL were 30:70 and 40:60 in proportions of 1:0.5 and 1:1 Eudragit®−arginine. The microcapsules were morphostructurally characterized by scanning electron microscopy, and a microelement analysis was performed via energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. Additionally, in vitro digestibility was used to determine the protection efficiency. Both encapsulated systems presented regular (crystals) and spherical (microcapsules) polyhedral morphologies. Qualitative nitrogen decreased significantly as the wax ratio increased in the wax−arginine formulations. The formulations with a 1:1 Eudragit:−arginine ratio (1000 mg arginine) produced a higher nitrogen content in the en... [more]
579. LAPSE:2024.1852
Special Issue: Biochemical Processes for Sustainability
August 23, 2024 (v1)
Subject: Process Design
Currently, we are faced with the need to develop solution that are sustainable in terms of the energy and material resources used, which implies environmental sustainability [...]
580. LAPSE:2024.1851
Key Takeaways on the Cost-Effective Production of Cellulosic Sugars at Large Scale
August 23, 2024 (v1)
Subject: Materials
Keywords: biorefinery, cellulosic sugar, enzymatic hydrolysis, lignocellulosic biomass, pretreatment.
The production of cellulosic sugars in lignocellulose biorefinery presents significant economic and environmental challenges due to the recalcitrant nature of biomass. The economic and facile production of renewable sugars with high yield and productivity is pivotal for the success of biorefinery. The cellulosic sugars are valorized either by biochemical routes or chemical routes or by hybrid (biological and chemical) routes into renewable chemicals, fuels, and materials. This manuscript focuses on the critical parameters affecting the economic viability of cellulosic sugar production at large scale, including biomass-specific pretreatment strategies and enzyme cost efficiency. High pretreatment costs, carbohydrate loss, and inhibitors production during pretreatment are identified as major contributors to overall production costs. To address these issues, we highlight the importance of developing cost-effective and efficient pretreatment methods tailored to specific biomass types and s... [more]
581. LAPSE:2024.1850
Study of Low-Temperature Energy Consumption Optimization of Battery Electric Vehicle Air Conditioning Systems Considering Blower Efficiency
August 23, 2024 (v1)
Subject: Energy Systems
Keywords: air conditioning system, battery electric vehicle, blower, low-temperature energy consumption, PTC heater, total power consumption.
Battery electric vehicle (BEV) air conditioning systems often use positive temperature coefficient (PTC) heaters to heat the passenger compartment. The heating process consumes a lot of energy in low-temperature environments, which seriously affects the driving range and user experience. This study aims to reduce the low-temperature energy consumption of the air conditioning system and improve energy efficiency through an innovative optimization method. In this study, the energy consumption composition of the air conditioning system was analyzed, and the goal of minimizing the sum of the total power consumption of the PTC heater and the blower was determined, while the efficiency characteristic of the blower was considered at the same time. The relationship between the average temperature of the passenger compartment measurement points and the PTC power and airflow rate was studied by combining experiments and numerical simulations, and the alternative operating conditions that met the... [more]
582. LAPSE:2024.1849
Numerical Simulation of Fishtail Biomimetic Groove for Dry Gas Seals
August 23, 2024 (v1)
Subject: Modelling and Simulations
Keywords: biomimetic design, carp-tail groove, dry gas seal, numerical simulation, seal performance.
In recent years, the use of dry gas seal technology in high-end industrial applications has become increasingly widespread. Existing research has primarily focused on unidirectional grooves. This study introduces an innovative approach by incorporating bidirectional grooves inspired by the biomimetic design of a carp tail, aiming to enhance sealing performance. The analysis of flow-field characteristics was conducted using Fluent software to evaluate the effect of different groove designs on sealing efficacy. The results indicate that curved grooves are more effective in directing gas flow and reducing fluid dynamic losses, thus improving the overall sealing efficiency. In particular, the outer-curved carp-tail groove exhibited superior dynamic pressure effects and reduced pressure drops across various operating conditions. The optimal radial dam-to-groove width ratio ranged from 3.8 to 4.1, and the optimal groove depth ranged from 6.5 to 9.6 μm. This investigation focused on the desig... [more]
583. LAPSE:2024.1848
Research on Intelligent Scheduling Strategy for Electric Heavy Trucks Considering Photovoltaic Outputs
August 23, 2024 (v1)
Subject: Planning & Scheduling
Keywords: electric heavy trucks, intelligent scheduling strategy, photovoltaic output, photovoltaic storage charging station, sensitivity analysis.
Due to the extensive use of fossil fuels, energy conservation and sustainable transportation have become hot topics. Electric vehicles (EVs), renowned for their clean and eco-friendly attributes, have garnered considerable global attention and are progressively being embraced worldwide. However, disorganized EV charging not only reduces charging station efficiency but also threatens power grid stability. In this low-carbon era, photovoltaic storage charging stations offer a solution that accommodates future EV growth. However, due to the significant instability in both the charging load and photovoltaic power generation within charging stations, it is critical to maximize local photovoltaic power consumption and minimize the impact of disorganized EV charging on the power grid. This paper formulates an intelligent scheduling strategy for electric heavy trucks within charging stations based on typical photovoltaic output data. The study focuses on a photovoltaic storage charging station... [more]
584. LAPSE:2024.1847
Double-Closed-Loop Model Predictive Control Based on a Linear Induction Motor
August 23, 2024 (v1)
Subject: Electricity & Electrical Devices
Keywords: linear induction motor, model predictive current control, model predictive speed control.
The conventional PI control, which has been extensively employed in the high-performance control of linear induction motors, has the benefit of a straightforward concept, quick dynamic response, and simple control. Nevertheless, the linear induction motor is more susceptible to outside disturbances and mismatched parameters since it is a highly linked, high-order, nonlinear, time-varying, complex system. Because of this, this paper proposes a double-closed-loop control of the linear induction motor, whose speed and current loops are the model-predictive speed controller and the model-predictive current controller, respectively, to solve the problems of speed overshoot and oscillation when the linear induction motor is operated under PI control. The findings demonstrate the benefits of the suggested control strategy, which significantly enhances the linear induction motor’s speed control performance. These benefits include improved dynamic performance, limited overshooting, and robust r... [more]
585. LAPSE:2024.1846
Three-Dimensional Physical Test Study on the Overburden Breaking Behavior of Non-Penetrating Pre-Splitting in Small-Coal-Pillar Roadway Roofs
August 23, 2024 (v1)
Subject: Energy Systems
Keywords: apparent resistivity change rate, electromagnetic wave propagation, non-penetrating pre-splitting, small coal pillar, three-dimensional physical test.
In longwall coal mining, significant deformation of small-pillar roadways presents challenges for the safe and efficient retreat of mining panels. Non-penetrating directional pre-splitting alters the roof structure of these roadways and effectively manages their stability under high stress during mining operations. In this study, a three-dimensional experimental model for the non-penetrating pre-splitting of small-coal-pillar roadway roofs was established, the apparent resistivity change in the rock layer during mining of the working face was determined, the propagation law of high-frequency electromagnetic waves in the overlying rock was studied, and the stress distribution law of the surrounding rock was investigated. After non-penetrating pre-splitting in the roof, the apparent resistivity change rate of the overlying rock increased and the electromagnetic waveform exhibited scattering and diffraction, forming a short cantilever beam. After mining, the stress in the adjacent mining... [more]
586. LAPSE:2024.1845
A Promising Biocontrol Agent of Bacillus velezensis VC3 against Magnaporthe oryzae and Colletotrichum gloeosporioides in Plants
August 23, 2024 (v1)
Subject: Biosystems
Keywords: antifungal activity, Bacillus velezensis, biocontrol, phytopathogenic fungi, secondary metabolites.
Fungal diseases of plants are one of the key factors causing global crop losses. In this study, we isolated a Bacillus velezensis strain VC3, which was found to have a broad-spectrum inhibitory effect on a variety of phytopathogenic fungi through in vitro and in planta experiments, especially on Magnaporthe oryzae and Colletotrichum gloeosporioides. Further genomic and transcriptomic analyses revealed that the B. velezensis VC3 has multiple functional gene clusters encoding for the synthesis of a variety of antifungal secondary metabolites, including antimicrobial peptides (AMPs) and lipopeptides (LPs). In addition, AMPs and LPs were isolated and purified from B. velezensis VC3 fermentation broth and their antifungal activities were verified in this study. AMPs and LPs significantly inhibited spore germination, appressorium formation, and disease development, and AMPs have a better potential for controlling M. oryzae and C. gloeosporioides than LPs. These findings open new avenues for... [more]
587. LAPSE:2024.1844
A Review of the Utilization of CO2 as a Cushion Gas in Underground Natural Gas Storage
August 23, 2024 (v1)
Subject: Energy Systems
Keywords: cushion gas, influencing factor, mixing degree, underground natural gas storage.
A cushion gas is an indispensable and the most expensive part of underground natural gas storage. Using CO2 injection to provide a cushion gas, not only can the investment in natural gas storage construction be reduced but the greenhouse effect can also be reduced. Currently, the related research about the mechanism and laws of CO2 as a cushion gas in gas storage is not sufficient. Consequently, the difference in the physical properties of CO2 and CH4, and the mixing factors between CO2 and natural gas, including the geological conditions and injection−production parameters, are comprehensively discussed. Additionally, the impact of CO2 as a cushion gas on the reservoir stability and gas storage capacity is also analyzed by comparing the current research findings. The difference in the viscosity, density, and compressibility factor between CO2 and CH4 ensures a low degree of mixing between CO2 and natural gas underground, thereby improving the recovery of CH4 in the operation process o... [more]
588. LAPSE:2024.1843
The Research on Microwave Drying Characteristics of Polyethylene Terephthalate Materials Based on Frequency and Power Tuning Technology
August 23, 2024 (v1)
Subject: Materials
Keywords: COVT, frequency and power tuning, heating uniformity, logistic model, microwave heating effect, MR, permittivity, PET, R-square.
Polyethylene Terephthalate (PET), renowned for its exceptional physical and chemical properties, finds widespread use in our daily lives. However, conventional PET drying methods are time consuming and energy intensive. Leveraging microwave heating effects, we investigated drying characteristics concerning both microwave parameters and PET permittivity. The PET permittivity variation during heating is related to the microwave reflection at the incident port. Our innovative approach involves frequency and power tuning based on reflection. This method not only significantly improved heating uniformity and reduced temperature covariance (COVT) but also led to a more uniformly distributed temperature profile and a drastic reduction in energy consumption. Integrating precise and rapid frequency tuning, we compared our method’s efficiency with traditional approaches, revealing an impressive time savings of 2 h and an energy consumption limited to approximately less than 3 kWh/kg. Notably, ou... [more]
589. LAPSE:2024.1842
Decoding the Effect of Synthesis Factors on Morphology of Nanomaterials: A Case Study to Identify and Optimize Experimental Conditions for Silver Nanowires
August 23, 2024 (v1)
Subject: Materials
Keywords: automated image analysis, silver nanowires, successive nanomaterial synthesis, ultralong nanowires.
Silver nanowires (AgNWs) are one kind of nanomaterials for various applications such as solar panel cells and biosensors. However, the morphology of AgNWs, particularly their length and diameter, plays a critical role in determining the efficiency of energy storage systems and the transmittance of biosensors. Thus, it is imperative to study synthesis strategy for morphology control. This study focuses on synthesizing AgNWs through the solvothermal approach and aims to understand the individual and combined effects of three nucleants, NaCl, Fe(NO3)3 and NaBr, on the morphology of AgNWs. Using a modified successive multistep growth (SMG) approach and fine-tuning the nucleant concentrations, this study synthesized AgNWs with controllable aspect ratios, while minimizing the presence of undesirable byproducts like nanoparticles. Our results demonstrated the successful synthesis of AgNWs with favorable morphologies, including lengths of approximately 180 µm and diameters of 40 nm, thus resul... [more]
590. LAPSE:2024.1841
Analytical Solution for Contaminant Transport through a Soil−Bentonite (SB)/Geosynthetic Clay Liner (GCL)/Soil−Bentonite (SB) Composite Cutoff Wall and an Aquifer
August 23, 2024 (v1)
Subject: Optimization
Keywords: advection, analytical solution, composite cutoff wall (CCW), contaminant transport, GCL.
This study develops a one-dimensional analytical solution for contaminant advection, diffusion and adsorption through a soil−bentonite (SB)/geosynthetic clay liner (GCL)/SB−aquifer composite cutoff wall (CCW) system. The solution agrees well with an existing double-layer model. Adopting toluene as a representative contaminant, using the present solution, the analysis systematically investigates the impact of hydraulic gradient (i) and the hydraulic conductivities of GCL (kgcl) and SB (ksb). The results show the following: (1) Increasing i from 0.1 to 1 reduces the concentration breakthrough time (tcb) from 20 to 11 years and mass flux breakthrough time (tfb) from infinite to 11 years, indicating lower i significantly extend both tcb and tfb, which is crucial for optimizing CCW barrier performance; (2) lowering kgcl from 5.0 × 10−11 m/s to 1 × 10−12 m/s and reducing ksb from 1.0 × 10−9 m/s to 1.0 × 10−11 m/s, would increase the tcb by 36% and 100%, respectively. It demonstrates that red... [more]
591. LAPSE:2024.1840
Towards Sustainable Lithium-Ion Battery Recycling: Advancements in Circular Hydrometallurgy
August 23, 2024 (v1)
Subject: Environment
Keywords: circular economy, circular hydrometallurgy, Li-ion battery recycling, metal separation.
The growing demand for lithium-ion batteries (LIBs) has led to significant environmental and resource challenges, such as the toxicity of LIBs’ waste, which pose severe environmental and health risks, and the criticality of some of their components. Efficient recycling processes are essential to mitigate these issues, promoting the recovery of valuable materials and reducing environmental pollution. This review explores the application of electrodialysis in the process of recycling LIBs to contribute to the principles of circular hydrometallurgy. The article is structured to provide a comprehensive understanding of the topic, starting with an overview of the environmental and resource challenges associated with manufacturing LIBs. Then the current recycling processes are presented, focusing on hydrometallurgical methods. The concept of circular hydrometallurgy is introduced, emphasizing sustainable resource recovery. The electrodialysis technique is described in this context, highlight... [more]
592. LAPSE:2024.1839
Fault Diagnosis Method of Bearings Based on SCSSA-VMD-MCKD
August 23, 2024 (v1)
Subject: Process Control
Keywords: fault diagnosis, Maximum Correlated Kurtosis Deconvolution, rolling bearings, Sparrow Search Algorithm, Variational Mode Decomposition.
To tackle the issue of detecting early, subtle faults in rolling bearings in the presence of noise interference, the SCSSA-VMD-MCKD method is suggested. This method optimizes the Variational Mode Decomposition (VMD) and Maximum Correlated Kurtosis Deconvolution (MCKD) by integrating the sine-cosine and Cauchy Mutation Sparrow Search Algorithm (SCSSA). The approach aims to effectively diagnose faults in rolling bearings by leveraging the strengths of VMD and MCKD in noise reduction and highlighting fault frequencies. The method utilizes the SCSSA algorithm to autonomously search for parameters in both VMD and MCKD, using the EnvelopeCrest Factor Ec as a fitness function. Firstly, SCSSA is employed to optimize the decomposition mode number K and penalty factor α in the VMD algorithm. Secondly, the parameters in the MCKD algorithm are optimized, and MCKD is used for deconvolution to enhance the impulsive characteristics of the best modal component. Finally, the signal is further analyzed... [more]
593. LAPSE:2024.1838
Research on an Adaptive Active Suspension Leveling Control Method for Special Vehicles
August 23, 2024 (v1)
Subject: Process Control
Keywords: active suspension, automatic leveling, gyroscope, hydraulic cylinders, Kalman filtering, PID.
Adaptive active suspension systems, integral to specialized vehicles, hold significance for their stability and safety. This study introduces a novel adaptive active suspension system featuring four independently controlled wheels employing wheel-hub motors, hydraulic cylinders, pump motor power, controllers, and sensors. A rapid and, within a certain range, leveling and height adjustment control strategy is proposed for this system, utilizing the Kalman filter algorithm. Additionally, the paper examines the front-wheel Ackermann steering model and four-wheel reverse Ackermann transition model to enhance the suspension’s stability. Subsequently, experiments on leveling and height adjustment are conducted, demonstrating the system’s capability to swiftly and accurately rectify the vehicle’s deviation angle within the specified threshold. Following adjustments made by the leveling and height control algorithm, the vehicle body promptly returns to the preset level state and designated hei... [more]
594. LAPSE:2024.1837
3D Printer Nozzle Structure Form Optimal Structural Analysis
August 23, 2024 (v1)
Subject: Materials
Keywords: 3D printing, COMSOL simulation, FDM technology, nozzle structure, orthogonal test.
The most representative technology of 3D printing is fused deposition modeling (FDM). To improve the printing accuracy of FDM technology, this paper first takes the outlet diameter, angle of convergence, and rectifier section length of the nozzle as the influencing factors. It takes the melt outlet speed stability, viscosity, and outlet pressure as the indexes to design the orthogonal test. Then, COMSOL Multiphysics fluid−solid coupling simulation was used to simulate and analyze the structural characteristics of the 3D printer nozzle, and the range analysis method was used to analyze the data. Finally, the two-phase flow combination was used to simulate the morphological characteristics of the melt flowing out of the nozzle. The results show that the simulation results of the two materials are similar. As the nozzle diameter decreases, the melt pressure decreases, the velocity increases, and the viscosity decreases. For PLA wire rods, the optimal structure of the nozzle is that the ou... [more]
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