Disk Speed Research Articles

Parameter Optimization Method for Centrifugal Feed Disc Discharging Based on Numerical Simulation and Response Surface

In this study, a centrifugal feeding disc device is proposed. To investigate the influence of the process parameters on the discharging efficiency and the lifting of the discharging efficiency, the centrifugal feeding disc device was dynamically simulated based on the discrete element method (DEM), and the simulation results were experimentally verified. Based on the quadratic regression orthogonal test method, a significant lossless regression model of process parameters and discharging efficiency was established, and the response surface of the interaction of process parameters was obtained. The results indicated that the order of influence of the process parameters on the discharging speed of the centrifugal feeding disc was as follows: outer turntable speed > inner turntable speed > inner turntable tilt angle > conical turntable angle. The interaction of the conical turntable angle and the inner turntable tilt angle had the greatest influence on the centrifugal feed disc discharge efficiency. The response surface method (RSM) was used to optimize the process parameters, and the optimal combination of process parameters included an outer turntable speed of 135 r/min, an inner turntable speed of 64 r/min, an inner turntable tilt angle of 7°, and a conical angle of 15°. The discharged efficiency of the optimized centrifugal feeding disc device was increased by 31.9%.

Optimization of Velocity String Drainage and Gas Recovery Process for Sour Gas Wells in Jingbian Gas Field

Abstract In view of the gradual attenuation of gas well energy during the development of Jingbian gas field, the liquid carrying effect of some gas wells with small gas production becomes worse, the drainage effect of 60 % gas wells is not ideal, and the H2S content of the lower paleo-sulfur gas wells is high, the salinity is high, there is a certain corrosion, and most of the drainage measures cannot be implemented. The optimization of sulfur-resistant velocity string was carried out from the aspects of velocity string size and pipe material, and the appropriate pipe diameter and pipe material were selected. A new type of broken disc speed string plug was developed, which successfully solved the problem that the existing plug could not be broken or returned after construction. The field application results show that compared with the 27/8 “ string, the liquid carrying flow rate is reduced by 82 %. After 2.5 years of service, the anti-corrosion performance of the pipe is good. The cumulative increase of the well is 445.4 thousand cubic meters, and the effective rate of the measures is 97.45 %. The stable and continuous liquid carrying of the gas well is realized, which has a good application effect. It has certain reference significance for the implementation of the drainage gas recovery technology of the velocity string in the lower ancient sulfur gas well.

Performance evaluation of designated containerization and virtualization solutions using a synthetic benchmark

The aim of this paper is the analysis of the performance of virtualization and containerization technologies in the context of IT infrastructure. The following virtualization technologies were selected for the study: VirtualBox, VMware and QEMU, as well as containerization technologies: Docker, Podman and LXD. In addition, microVM technologies such as QEMU and Firecracker, which are increasingly important in the context of virtualization, were also included. The comparative criteria on which the analysis is based include aspects of computing and memory performance. Tests conducted on selected technologies included testing CPU performance, RAM efficiency and disk speed for reading and writing data. A SysBench, synthetic benchmark, was used to conduct the tests.

Non-smooth self-excited vibration of a novel dynamical model for a disc brake

This paper proposes a new dynamic model for the study of friction-induced self-excited vibration of a disc brake system, where the pad’s motions in both radial and circumferential/tangential directions are included, which is in stark contrast to the previous studies that normally consider the pad’s motion in the tangential/circumferential direction only. The non-smooth dynamics of the system including three different states of motion, i.e., stick, slip and separation, is investigated. Both the linear stability analysis and the transient dynamic analysis are performed. The numerical results in the linear stability analysis indicate that the inclusion of pad’s radial motion in the present brake model significantly expands the ranges of operating parameters for dynamic instability than the brake model with only circumferential/tangential motion for the pad. For the transient dynamic analysis, two different methods, i.e., the time integration method and the shooting method, are employed for the calculation of steady-state response. The accuracy and efficiency of the shooting method are subsequently examined. The numerical results show rich bifurcation behaviours of the steady-state response in the present brake model with the variations of brake pressure and disc speed , and (the stiffness of the inclined spring in the radial direction) is a key parameter for controlling the occurrence of chaotic vibration in the system. Conflict of Interest Statement The authors declare no conflicts of interest.

Simulation and analysis of the electro-hydraulic coordinated system for the disc brake system in mining belt conveyor

The present study aims to investigate the dynamic performance of the disk hydraulic brake system in a mining belt conveyor. To achieve this, a simulation model of the hydraulic system for the belt conveyor is designed and constructed using AMESim. It is recognized that brake disk deformation can lead to brake shock, thus an ADAMS rigid-flexible coupling model for hydraulic disk brakes is established. Furthermore, the concept of rigid-flexible coupling mechanical systems is introduced into the hydraulic system to enable interaction between physical quantities. Use fuzzy logic rules to adjust parameters in Simulink, and in response to the suboptimal control of braking and acceleration, a compact non-model-based adaptive algorithm is incorporated into the conventional PID control algorithm. Employing mechanical modeling and multidisciplinary dynamic collaborative simulation technology, a simulation system integrating electromechanical and hydraulic aspects is developed for the disk hydraulic brake of belt conveyors. This system is employed to conduct simulation studies on the closed-loop control of braking disk speed and deceleration/acceleration for belt conveyors. The study findings reveal that the non-model-based adaptive PID control algorithm, in comparison to fuzzy PID, not only demonstrates quicker and more stable responses across various dynamic performance curves but also markedly reduces the axial oscillation amplitude of the braking disk under braking conditions.

Enhancing tribological performance of hybrid fiber-reinforced composites through machine learning and response surface methodology

This study delves into the significant effects of sodium hydroxide (NaOH) treatment on the tribological properties of hybrid fiber-reinforced composites, specifically focusing on the combination of paddy straw (PS) and pineapple leaf (PALF) in a polyester matrix. By leveraging Artificial Neural Networks (ANNs) to predict the Specific Wear Rate (SWR) and Coefficient of Friction (COF), the research employs a grid search approach for hyperparameter optimization. This optimization process results in an optimal ANN architecture with impressive accuracy, showcasing low mean absolute error and high R-squared values of 0.991 and 0.986 for SWR and COF predictions, respectively. Utilizing the Design of Experiments (DOE), the study systematically analyzes the intricate interplay of disc speed, wear duration, and NaOH treatment percentage, with a specific focus on SWR and COF as pivotal tribological metrics. The Analysis of Variance (ANOVA) results underscore the substantial impact of duration and treatment percentage on wear characteristics. Additionally, quadratic regression models reveal nuanced correlations, highlighting the sensitivity of SWR to NaOH percentage and the influence of disc speed, duration, and treatment percentage on COF. This outcome emphasizes the efficacy of these parameters in achieving superior tribological performance in hybrid composites. Beyond contributing to a profound understanding of wear characteristics, this work introduces an innovative dimension through optimized ANN modeling, ensuring a more accurate and fine-tuned predictive model.

Tribological investigation into nickel-coated graphite polytetrafluoroethylene composites

The friction and wear resistance of polytetrafluoroethylene (PTFE) composites can be enhanced by incorporating nickel-coated graphite. An electroless coating method employing Gin plates (418A, 418B) is utilized to produce nickel-coated graphite. X-ray diffractometer analysis reveals the presence of nickel and graphite peaks in the coated graphite powders at 44° and 26.4°, respectively. Scanning electron microscopy images confirm the presence of nickel coating on graphite particles. Tribological tests using a pin-on-disc tribometer (L9) demonstrate that composites filled with 20 wt.% Nickel-coated graphite exhibits the lowest wear rate of 220 µm, compared to 1166 µm for pure PTFE specimens. The notable improvement in wear resistance is attributed to enhanced bonding strength between the filler and matrix material. Pure PTFE exhibits varying coefficient of friction (CoF) at different parameters, with the highest and lowest CoF observed at 200 rpm, 20N and 180 rpm, 10 N, respectively. Optimal parameters for minimizing wear rate and CoF, determined through analysis of means, include a 20 wt.% filler concentration, disc speed of 180 rpm, and 10N load. Analysis of variance identifies composition and speed as primary factors affecting wear and CoF.

Analysis of friction-induced vibration and wear characteristics during high-speed train friction braking process

This study explored the evolution of friction-induced vibration (FIV) and wear in high-speed train friction braking through experiments, theoretical analysis, and numerical simulation. Experimental tests revealed that vibration behavior transitions from high-frequency modes at high speeds to low-frequency stick-slip at lower speeds. Theoretical analysis indicated that brake disc speed, coefficient of friction (COF), and contact stiffness affect system stability. Specifically, the system experiences high-frequency vibrations at high speeds due to mode coupling, and the friction block surface primarily undergoes abrasive wear mechanisms. At lower speeds, the system demonstrates low-frequency stick-slip vibrations induced by the combined effects of mode coupling and negative friction velocity slope (NFVS) characteristics, and the friction block surface mainly experiences adhesive wear mechanisms.

Modeling of the Efficiency of the Centrifugal Conical Disk Dispenser of Bulk Materials.

Centrifugal disk dispensers are widely used in various tasks of dosing bulk, dispersed materials. The design of the disk depends on the physical and mechanical characteristics of the dosing medium. The work discusses the development of an analytical model of the movement of a material particle along a conical centrifugal disk depending on the kinematic characteristics of the dosing process and the characteristics of the dosing material, as well as experimental confirmation of the theoretical model, which is relevant for the calculation and design of working elements of this type. The obtained system of differential equations is solved using the Runge-Kutta numerical method. Experimental studies were carried out using the method of a planned factorial experiment. The experiment was conducted for three factors at three levels. The feedback criterion was the performance of a centrifugal conical disk dispenser for bulk materials. The disk cone angle was set at 10, 20, and 30°. The disk diameter was 130, 150, and 170 mm, the gap between the disk and the edge of the hopper neck was 6, 8, and 10 mm, and the rotational speed of the conical disk was 0.65, 1.02, and 1.39 rad/s. The dispensing rate of the dispenser ranged from 15 to 770 g/s, depending on the values of the experimental factors. For use in the regression equation of the natural values of the factors, a method of transforming the terms of the equation from coded values to natural ones is provided. The obtained experimental correlation dependencies were checked for reproducibility with Cochrane's test, and the adequacy of the model was checked using Fisher's test. The significance of the coefficients in the correlation equation was evaluated using the Student's t-test. The difference between the experimental data and the results of the theoretical modeling does not exceed 5%. The obtained system of differential equations makes it possible to model the radial velocity of the ascent of bulk material from the conical rotating disk depending on the rotation frequency, disk diameter, and the height of the annular gap between the discharge throat of the hopper and the conical disk. The analytical model enables the modeling of the productivity of the conical dispenser for bulk materials for arbitrary parameters of rotation frequency, disk diameter, and the size of the annular gap between the discharge throat of the hopper and the conical disk.

Optimized machine learning with hyperparameter tuning and response surface methodology for predicting tribological performance in bio‐composite materials

AbstractThis study investigates the influence of NaOH treatment on tribological behavior in hybrid fiber‐reinforced composites, specifically employing Banana fiber with Al2O3 filler in an epoxy matrix. Through design of experiments (DOE), disc speed, wear duration, and NaOH treatment are analyzed for specific wear rate (SWR) and coefficient of friction (COF). To advance the understanding of wear characteristics, the study leverages advanced machine learning, using Python‐powered artificial neural networks (ANN), is integrated with innovative ANN hyperparameter optimization. Optimized parameters (1050 rpm, 60 s, 5% treatment) significantly minimize SWR (12.38 × 10−5 mm3/Nm) and COF (0.2). Scanning electron microscopy (SEM) analysis reveals improved interfacial adhesion and identifies micro‐cracks as the primary wear mechanism. This work contributes to a profound understanding of wear in hybrid composites, offering a fine‐tuned predictive model for optimizing tribological behavior and advancing material science and engineering.Highlights Reduced SWR, COF in composites via NaOH optimization. DOE: Explored disc speed, duration, NaOH impact. Advanced machine learning techniques enhanced wear prediction. Innovative: ANN hyperparameter optimization. Optimal Parameters: 1050 rpm, 60 s, 5% treatment.

Toward Optimal Virtualization: An Updated Comparative Analysis of Docker and LXD Container Technologies

Traditional hypervisor-assisted virtualization is a leading virtualization technology in data centers, providing cost savings (CapEx and OpEx), high availability, and disaster recovery. However, its inherent overhead may hinder performance and seems not scale or be flexible enough for certain applications, such as microservices, where deploying an application using a virtual machine is a longer and resource-intensive process. Container-based virtualization has received attention, especially with Docker, as an alternative, which also facilitates continuous integration/continuous deployment (CI/CD). Meanwhile, LXD has reactivated the interest in Linux LXC containers, which provides unique operations, including live migration and full OS emulation. A careful analysis of both options is crucial for organizations to decide which best suits their needs. This study revisits key concepts about containers, exposes the advantages and limitations of each container technology, and provides an up-to-date performance comparison between both types of containers (applicational vs. system). Using extensive benchmarks and well-known workload metrics such as CPU scores, disk speed, and network throughput, we assess their performance and quantify their virtualization overhead. Our results show a clear overall trend toward meritorious performance and the maturity of both technologies (Docker and LXD), with low overhead and scalable performance. Notably, LXD shows greater stability with consistent performance variability.

Application of a centrifugal disc fertilizer spreading system for UAVs in rice fields

Unmanned aerial vehicle (UAV) granular fertilizer spreading technology has been gradually applied in agricultural production. However, in the process of spreading operation, the actual influence effect of each factor in field operation is still unclear. Based on the self-developed UAV fertilizer spreading system, this paper explores the effects of three factors, the baffle retraction (B), spreading disc speed (D), and UAV flight altitude (H), on the granular fertilizer spreading effect in the actual field scenarios through the orthogonal test and taking the coefficient of variation (Cv) and relative error of fertilizer application rate (λ) as the evaluation indexes. The results showed that the optimal factor level combination of Cv was 11.23 % for BbDbHa (the baffle retraction is 6 %, spreading disc speed is 600r/min, and UAV flight height is 1.5 m) at UAV flight speed of 2 m/s. The best factor level combination for λ was BbDbHb of 7.99 % (the baffle retraction is 6 %, spreading disc speed is 600r/min, and UAV flight height is 2 m). In addition, by analysing the influence of the weather and the vortex of the rice canopy on the actual spreading effect, it was found that the weather has less influence on the spreading effect of this system, while the vortex caused by the airflow of the UAV rotor has a certain influence on the spreading effect, which is also relatively easy to ignore in fertilizer spreading operations. The results of the study can be used to explore the operational effects of actual fertilizer application by UAVs in rice field, which will help promote the development of UAV spreading technology and provide a reference for precision fertilizer application through agricultural aviation.

Effect of Vibration Conditions on the Seed Suction Performance of an Air-Suction Precision Seeder for Small Seeds

The air-suction precision seeder for small seeds is a planting machine, characterized by precision, high efficiency, and ease of operation, that uses air suction technology to sow small grain seeds at set intervals and depths into the soil. However, the forced vibration, enhanced by the increase in the operating speed, affects the seeding accuracy of the seeder and limits the seeding efficiency. To study the influence of vibration conditions on the seed suction performance of the air-suction precision seeder, we developed a computational fluid dynamics–discrete element coupling method to construct a bidirectional fluid–solid coupling numerical simulation model of the seed suction process under vibration conditions. Within the range of operating speeds from 0.6 km/h to 8 km/h, we quantitatively studied the population movement under different vibration frequencies, vibration amplitudes, negative pressure values, and seeding disc speeds and verified the simulation model and its analysis results through bench tests. The numerical results show that the interaction between the vibration frequency, vibration amplitude, and negative pressure value has the most significant impact on the single-seed rate. In addition, via variance analysis and response surface analysis, the optimal range of negative pressure values for achieving high single-seed rates under different vibration frequencies (4~10 Hz), vibration amplitudes (3~7.5 mm), and seeding disc speeds (4~50 rpm) was determined. The results indicate that, rather than the higher the negative pressure value, the higher the seed suction rate, the optimal negative pressure value for achieving a high seed suction rate varies with the specific vibration frequencies and amplitudes.

Optimization of MRP quartz glass process parameters based on BP-PSO

ABSTRACT The BP-PSO was used to obtain the optimal process parameters of magnetorheological polishing quartz glass. Specifically, the orthogonal experiments investigated the effect of process parameters on processing properties. A BP prediction model was constructed with process parameters as input and comprehensive evaluation Z as output. Based on the model, PSO was used to optimize process parameters, and experimental validation was conducted. It turns out that the relationship of MRR with workpiece speed is linear, with working gap and polishing disc speed are sinusoidal, and with yaw speed is quadratic. The relationship between Sa and four process parameters are quadratic. The R2 of the model is 0.9609. The error of the predicted Z is less than 3.45%. The optimal combination predicted is: workpiece speed 700r/min, working gap 3.1mm, yaw speed 115mm/min, and polishing disc speed 60r/min. The predicted Z is 39.96, the actual Z is 41.93, with an error of 4.9%.

Intensification of evaporative precipitation of lignin in a spinning disc evaporator

A continuous process for the evaporative precipitation of lignin derived from Organosolv black liquor was successfully developed and implemented in a spinning disc evaporator (SDE). A maximum of 95 % of the lignin was recovered at a disc speed of 1200 rpm, black liquor feed flow rate of 1 ml s−1 on a smooth disc surface heated to 100 ⁰C. These optimal flow rate and disc speed values corresponded to conditions which maximised residence time to <1 s in 4 disc passes without compromising on the rate of evaporative heat transfer. The lignin precipitate did not have any detectable impurities present after being washed and dried. The particle size for the lignin precipitate was in the region of 3 – 9 µm with minor agglomeration occurring, providing good filterability. A scaled up version of the process was modelled for benchmarking purposes and it was found that the SDE had a better theoretical performance than a falling film evaporator (FFE) system developed for the same process, with the energy consumption reduced by 23% and a higher lignin recovery rate per volume of black liquid processed once adjusted for processing time (38.1 g L−1 h−1 for the SDE vs. 3.23 g L−1 h−1 for the FFE).

Tribo‐performance assessment of brake friction composites prepared from agro‐industrial‐sea wastes using pin‐on‐disc

AbstractIn this work, eco‐friendly brake friction composites were developed using walnut shell powder‐fly ash‐white ark shell powder (agro‐industrial‐sea waste). The waste materials content in the friction composites varied from 33 to 53 wt% including a fixed content of fly ash (30 wt%) and walnut shell powder (3 wt%) and a varying amount of white ark shell powder (WASP) from 0 to 20 wt% with a step of 5 wt%. The fabricated specimens were characterized for tribo‐performance and compared with commercial brake lining specimen (CBLS) in compliance with ASTM G99 standards using pin‐on‐disc test setup under dry conditions. The specimens were tested for the disc speed varying from 500 to 2000 rpm under 50 and 150 N of normal loads. The friction coefficients and volume loss of the fabricated specimens were found insensitive to the compositional changes and highly sensitive to the normal load and disc speeds. SEM‐EDS analysis showed the frequent formation of friction films at higher disc speed and integration and disintegration of contact plateaus responsible for the changes in the friction and wear behavior. The direct comparison between the friction coefficient and volume loss indicated that 10 wt% of WASP in compensation with BaSO4 may be used to develop the brake friction composite.Highlights Brake friction composites prepared from the waste materials offered μ‐values from 0.31 to 0.6 in comparison with the CBLS. Friction coefficient dropped significantly at higher disc speed. Morphological and elemental analysis supported in estimating the probable friction and wear mechanisms.

Numerical Simulation of Liquid Film Characteristics during Atomization of Aluminum Alloy Powder

The process of atomizing aluminum alloy powder using a rotating disk was studied by numerical simulation and experimental verification. The motion characteristics of the molten metal thin liquid film and the evolution law of atomization into droplets were systematically studied with different disk shapes and speeds. The results showed that the slippage of the liquid film on the surface of the spherical disk was smaller, the liquid film spread more evenly, and the velocity distribution was more uniform. Under the same working condition, the boundary diameter of the continuous liquid film on the spherical disk was 21–29% larger, and the maximum liquid film velocity increased by approximately 19%. In other words, the liquid film obtained more energy at the same rotational speed, the energy utilization rate was higher, and the liquid filaments produced by the splitting region of the disk surface were finer and greater in number. The data showed that the average thickness of the liquid film on the surfaces of different disk shapes was more affected by the speed of the flat disk, and the thickness on the spherical disk was relatively stable and uniform, but the difference in thickness between the two disk shapes decreased from 4.2 μm to 0.3 μm when the speed increased from 10,000 rpm to 60,000 rpm. In particular, the influence of the disk shape on the liquid film thickness became smaller when the speed increased to a certain range. At the same time, the characteristics of the liquid film during the spreading movement of molten metal on the disk and the mechanisms of the primary and secondary breakage of the liquid film were obtained through this simulation study.

STUDY ON WEAR NATURE OF ALUMINUM 7075 HYBRID METAL MATRIX COMPOSITE

Aluminum 7075 alloy has garnered significant attention in various engineering applications due to its excellent strength-to-weight ratio and high corrosion resistance. In recent years, the incorporation of reinforcing fibers into aluminum matrices has emerged as a promising approach to enhance mechanical properties, including wear resistance. This study investigates the wear behavior of Aluminum 7075 composite reinforced with varying weight percentages (2%, 4%, and 6%) of boron carbide particles and 2% E-Glass short fibers. The composites were fabricated using the stir casting method, followed by heat treatment to optimize microstructure and mechanical properties. Wear tests were conducted using a pin-on-disc apparatus under dry sliding conditions, with parameters such as applied load, disc speed, and abrading distance being controlled. The wear surfaces were examined through scanning electron microscopy (SEM) analysis of worn surfaces. Results revealed that the addition of reinforcement particles effectively improved the wear resistance of the composite, with the 6% reinforcement exhibiting the highest resistance to wear.

Effect of a looming visual cue on situation awareness and perceived urgency in response to a takeover request

This study aimed to investigate the effect of a looming visual cue on situation awareness and perceived urgency in response to a takeover request (TOR), and to explore the underlying mechanisms of this effect through three experiments. In Experiment 1, the optimal size and speed of a red disk were determined, which were effective in capturing looming motion and conveying the urgency of the situation. The results indicated that both looming speed and size ratio had significant effects on situation awareness and perceived urgency. In Experiment 2, the effects of looming stimuli were compared with dimming stimuli, and the results showed that the looming visual cue was more effective in promoting perceived urgency and situation awareness. The results also indicated that the looming visual cue attracted more visual attention than the dimming visual cue, in line with previous studies. Experiment 3 utilized a driving simulator to test the effectiveness of the looming visual cue in promoting fast and appropriate responses to TORs in complex driving scenarios. The results showed that the looming visual cue was more effective in promoting perceived urgency and enhancing situation awareness, especially in highly complex driving situations. Overall, the findings suggest that the looming visual cue is a powerful tool for promoting fast and appropriate responses to TORs and enhancing situation awareness, particularly in complex driving scenarios. These results have important implications for designing effective TOR systems and improving driver safety on the road.

Optimization of operational parameters using RSM, ANN, and SVM in membrane integrated with rotating biological contactor

Membrane fouling is a critical bottleneck to the widespread adoption of membrane separation processes. It diminishes the membrane permeability and results in high operational energy costs. The current study presents optimizing the operating parameters of a novel rotating biological contactor (RBC) integrated with an external membrane (RBC + ME) that combines membrane technology with an RBC. In the RBC + ME, the membrane panel is placed external to the bioreactor. Response surface methodology (RSM) is applied to optimize the membrane permeability through three operating parameters (hydraulic retention time (HRT), rotational disk speed, and sludge retention time (SRT)). The artificial neural networks (ANN) and support vector machine (SVM) are implemented to depict the statistical modelling approach using experimental data sets. The results showed that all three operating parameters contribute significantly to the performance of the bioreactor. RSM revealed an optimum value of 40.7 rpm disk rotational speed, 18 h HRT and 12.4 d SRT, respectively. An ANN model with ten hidden layers provides the highest R2 value, while the SVM model with the Bayesian optimizer provides the highest R2. RSM, ANN, and SVM models reveal the highest R-square values of 0.97, 0.99, and 0.99, respectively. Machine learning techniques help predict the model based on the experimental results and training data sets.