Rotary Type Research Articles

MLDM: A Multi Learning Domain Model for Fault Identification of Centrifugal Fan

Abstract In centrifugal fan fault diagnosis, the influence of multiple noise sources causes the collected fault signals to contain interference of different modes. Therefore, the difficulty of capturing fault characteristics greatly increases in this situation. In this article, a Multi Learning Domain Model (MLDM) scheme is proposed based on signal processing technology and artificial intelligence methods. The Haar Wavelet Convolution Extraction (HaarCE) module in the scheme is used to synchronously map features at different frequency scales, while the Lightweight Multi-Scale Feature Enhancement (LMFE) module enhances feature extraction at different time scales. Meanwhile, Upsampling is employed to enhance the expression of fault features. In addition, applying Information Rectification Learning (IRL) to feature maps extracted at each level allows for spatial representation and selection of extracted fault features, providing a basis for final decision-making. This scheme performs multi-level and multi-scale analysis on fault signals, jointly extracting time, frequency, and spatial information to improve the robustness and generalization ability of the model. Conduct experimental verification using data from the same type of centrifugal fan and rotor. The experimental results show that the recognition accuracy of the proposed model is about 93% for fan data at SNR=-4dB, which has certain competitiveness compared to other excellent models.

Enhancing the efficiency of hydrokinetic Savonius turbine with guiding walls

AbstractHydropower offers a means of generating electricity through the conversion of water flow's mechanical energy using rotors. The helical Savonius rotor is recognized as one of the most commonly employed rotor types. An approach employed to boost power output involves the utilization of guiding walls, positioned upstream of the Savonius rotor. In this specific study, an investigation is presented into a helical Savonius rotor equipped with an innovative deflector design composed of guiding walls in the form of NACA‐profiled plates. Ansys Fluent is used to simulate the water flow around the helical Savonius turbine and the guiding walls. The geometric parameters of this design of guiding walls are adjusted to identify the most efficient configuration. When examining all considered configurations, an improvement is noted in the maximum power coefficient, with a significant increase compared with a conventional configuration. In fact, the power coefficient could be improved by 44% using optimal dimensions of the guiding walls. The inclusion of the proposed guiding walls in conjunction with the optimized geometric parameters emerges as a strategy to enhance the rotor's power coefficient.

Performance and Design Comparison of Coreless Axial Flux Permanent Magnet Machines With Different Typical Rotor Optimizations

Performance and Design Comparison of Coreless Axial Flux Permanent Magnet Machines With Different Typical Rotor Optimizations

Evaluasi Unjuk Kerja Screw Compressor UP5-15-10 di PT XYZ

This paper aims to evaluate the efficiency of screw compressor UP5- 15-10 used at PT XYZ. Screw compressor efficiency is a key factor in the operation of gas processing facilities, then a good understanding of screw compressor operation can improve operational efficiency and reduce energy consumption. The compressor used in this KKW is an Ingersoll Rand UP5-15-10. The UP5-15-10 compressor is used to power pneumatic tools and instrumentation equipment. The UP5-15-10 compressor is included in the rotary type positive displacement compressor, the compressor uses ambient air as its working fluid. UP5-15-10 screw compressor operation, including design data from the manual book and actual data such as incoming air capacity of 65 CFM at a temperature of 186 F with a pressure of 135 Psia getting a power of 13.74 kW from the power specification data of 15 kW obtained efficiency of 91%. The decrease in power in screw compressor UP5-15-10 by 9% is due to the difference in intake capacity between design and actual conditions, this is caused by process needs.

High temperature pyrolysis of sewage sludge: Synergistic effects of co-pyrolysis with rice straw and composite plastics wastes

The synergistic effect of co-pyrolysis for the mixtures of sewage sludge (SS), rice straw (RS) and composite plastic wastes (PE&PP) has been investigated with the aim of high gas yields and hydrogen generation. In this context, the applicability of high temperature pyrolysis technology was evaluated at both rotary type batch reactor and rotating screw type continuous reactor operating under the industrially relevant conditions. Gas yields have been improved at increasing the operating temperatures up to 850 °C. The gas yield of 75.06 % with its H2 portion of 32.35 % has been achieved as the best results for continuous pyrolysis unit at pilot scale. Secondary reactions such as steam de-alkylation, steam cracking, water gas shift and so on were regarded as being responsible for the high gas yields when the primary products of pyrolysis, i.e. condensable vapors, were much exposed to the hot zones inside the reactor. The dehydration of organic components involving the loss of water may supply steam to create a reactive pyrolysis atmosphere. While the pyrolysis of sewage sludge and rice straw favors CO and CO2 formation due to the high oxygen contents of these feedstocks, more methane and light olefins were produced when the plastics were added to the feedstock blends. This was ascribed to the initially generated radicals from the decomposition of sewage sludge and/or rice straw that might promote the scission reactions of plastics towards volatiles. It was shown that high temperature pyrolysis can be applied to a variety of organic wastes such as rice straw, sewage sludge and waste plastics. Conversion of wastes to hydrogen fosters the circular economy by putting the disposal costs down and creates a new route on renewable hydrogen generation.

Design and performance study of a novel variable cross-sectional rotor for twin-screw vacuum pumps

The variable cross-sectional rotor is considered as a potential technology to further improve the performance of twin-screw vacuum pumps, due to its remarkable advantages of large internal volume ratio. In this study, a mathematical model of variable cross-sectional rotors was established to obtain its generation method. A novel type of variable cross-sectional rotor was constructed by using the proposed method, and this rotor exhibits superior sealing performance. The variable cross-sectional rotor was geometrically compared with the traditional equal cross-sectional rotor. Then the accuracy of the proposed generation method as well as the advance of the generated variable cross-sectional rotor were verified by experimental test results. Results show that this design method achieves the construction of high accuracy variable cross-sectional rotors by generating 3-D helical surfaces. Compared with the traditional equal cross-sectional rotor, the geometric pumping speed and internal volume ratio of the variable cross-sectional rotor are increased by 7.57 % and 10.45 %, respectively. The volumetric efficiency of the variable cross-sectional rotor is increased by 6.52 % and the time to reach the ultimate pressure is reduced by 9.42 %, demonstrating superior pumping and sealing performance.

Cutting efficiency of different dental diamond rotary instruments for sectioning monolithic zirconia and lithium disilicate crowns

BackgroundThe aim of this study was to determine the cutting efficiency of different diamond rotary instrument types for sectioning monolithic zirconia and lithium disilicate anatomical crowns.Materials and methodsThe study used 30 diamond rotary instruments divided into three groups: Zirconia cutting diamond bur (White Z), super coarse grit diamond bur (KBlack), and medium coarse grit diamond bur (KBlue); Two subgroups were assigned based on the crown materials including monolithic zirconia (5YSZ) and lithium disilicate (e.max) ceramics. The cutting efficiency was assessed by measuring the time required to fully section the crowns, followed by scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) of the dental burs before use and after every sectioned crown. A three-way ANOVA examined the effects of bur type, material type, and sectioning stage. If interaction exists, one-way ANOVA was used to compare the different subgroups, followed by the Tukey post hoc test. The significance level was assigned at α ≤ 0.05.ResultsThe results exhibited various cutting efficiencies among diamond rotary instruments and ceramic crown materials. White Z demonstrated superior cutting efficiency of zirconia crown compared with KBlack and KBlue for the first cutting cycles (p ≤ 0.05); the results tend to be more comparable at the third cutting cycle. However, the super coarse diamond bur exhibited higher efficiency in cutting lithium disilicate crowns than white Z and KBlue burs through all three cutting cycles(p ≤ 0.05). The diamond bur-cutting efficiency diminished after each use, irrespective of the bur type or the crown material (p ≤ 0.05); this was represented by the reduction of carbon and increased nickel matrix ratio after each bur usage.ConclusionWhite Z diamond bur showed higher cutting efficiency of zirconia in the first two cutting cycles; super coarse diamond bur is more efficient for cutting lithium disilicate crown in all of the cutting cycles. The amount of diamond on the burs reduced after each use, with no great impact on the material type when sectioning lithium disilicate and 5YSZ crowns.Clinical significanceThis study provides valuable insights for dental practitioners in selecting the appropriate diamond rotary instrument for crown sectioning. Practitioners can minimize the risk of damage and reduce the time required for crown removal, improving patient outcomes.

Parametric Investigation of Rotary Type Magnetorheological Finishing Operation by Batch Gradient Descent Algorithm

Background: The consistency of the magnetorheological process insisted that the Inconel® 718 material should be furnished. This process involves every material from the categories of soft and hard materials. Aim: In this study, a cylindrical ferromagnetic work-part was finished using the magnetorheological finishing method. Objective: The strength of the magnetic flux controls the density and forces in processes that are assisted by magnetic fields. The mechanism was studied parametrically in this research work using response surface methodology Methods: Optimal process parameters were determined using response surface methodology to accurately execute the finishing procedure. Each parameter's percentage consumption to the process's finishing output was also estimated. The finishing of an industrial extrusion punch was carried out using the optimum parameters obtained from the parametric analysis. Results: The RSM optimisation of process parameters is validated using the batch gradient descent (BGD) algorithm which is the best fit and innovation algorithm for these types of optimization solutions. The mathematical model that BGD provides confirms the RSM mathematical model. Conclusion: The optimized parameters are useful in controlling the capability of the MR finishing process in various industrial applications.

Improvement of electromagnetic torque of BLDC motor for electrical cutter application

As the advancement of brushless direct current (BLDC) motor is rising, it has been an advantage to use the motor for a wide range of applications. Its robustness and torque development have benefited small applications, such as the agriculture cutter. However, dropping performances of conventional BLDC are affected by the shape of the rotor that has unused magnetic flux. Therefore, this research aimed to analyze the electromagnetic torque by reducing the unused flux from an electromagnetic point of view. Two BLDC models with different slot-pole numbers and rotor types were modeled and simulated with equal permanent magnet volume, and magnetomotive force (MMF). Finite element method (FEM) software was used to compute back electromotive force (BEMF), cogging torque, electromagnetic torque, and magnetic flux density of the BLDC models. As a result, 9/8 slot-pole with zero ferromagnetic underneath the permanent magnet had the highest BEMF and torque produced compared to the conventional type, with a percentage difference of 27%. In conclusion, this research presents the motor that had an improvement of electromagnetic torque for electrical cutter application.

Design and simulation of secondary acceleration type rotor for vertical shaft impact crusher

Design and simulation of secondary acceleration type rotor for vertical shaft impact crusher

The utility of temporal trends of blood biomarkers as predictors for bloodstream infections in left ventricular assist device recipients.

Temporal trends of routinely obtained parameters may provide valuable information for predicting BSIs, but this association has not yet been established in LVAD patients. This retrospective analysis included data from 347 consecutive recipients of three rotary LVAD types. Study endpoints included the incidence of BSI, the association of temporal trends of routinely obtained blood biomarkers with the development of BSIs, the incidence of BSIs, and survival on LVAD support. During follow-up, 47.8% (n = 166) of the patients developed BSI. In multivariate analyses, the development of BSI was a significant predictor of mortality (HR 5.78, 95% CI 4.08-8.19, p < 0.0001). In univariate analyses, after adjusting for potential confounders, albumin (SHR 0.94, 95% CI 0.91-0.97, p < 0.00010), creatinine (SHR 1.49, 95% CI 1.03-2.15, p = 0.033), and C-reactive protein (SHR 1.19, 95% CI 1.08-1.32, p = 0.0007) significantly predicted the development of BSIs during LVAD support. Notably, the strength of the association of parameter changes with the prediction of BSIs demonstrated a time-dependent correlation in the cases of albumin (p = 0.045) and creatinine (p = 0.003). Bloodstream infections are highly prevalent among LVAD recipients and are independent predictors of mortality. Temporal biomarker trends significantly predict the development of BSIs. These findings suggest opportunities for interventions aiming to reduce the incidence of BSIs.

Influence of Reynolds Number on Aerodynamic and Performance Coefficients of a Novel Parabolic-Bladed Savonius Wind Rotor

Abstract The vertical-axis Savonius wind rotor is known for its design simplicity, better starting qualities, and direction independency despite its inferior efficiency when measured against certain other types of vertical-axis wind rotors. Despite a plethora of research work on Savonius rotors, an in-depth analysis of Reynolds number (Re) on aerodynamic and power coefficients of the Savonius rotors is scarce. This paper aims at understanding the influence of Re on the performance of a novel parabolic blade profile through unsteady two-dimensional (2D) computation. The Reynolds-averaged Navier Stokes (RANS) equations are modelled using the ANSYS-Fluent by adopting shear stress transport (SST) k-ω turbulence model. The computational results of the novel blade profile are then compared and analysed with an established semicircular blade profile to draw some meaningful insights into the aerodynamic performance. In the tested range of Re = 5.3 × 104 − 10.6 × 104, the novel parabolic blade profile outperformed the semicircular blade profile in terms of aerodynamic and performance coefficients.

A robust calculation method of meshing clearance for screw rotor pairs

This study proposes a novel calculation method for meshing clearance between two mating screw rotors in compressors and vacuum pumps. The meshing clearance is obtained by calculating the minimum distance between the helix curves and the rotor surface. The 3D contact points of the screw rotor pair are found by applying the proposed algorithm. In particular, this method is robust enough to precisely calculate the clearance for the rotor type with several singular points where the shortest distance direction misaligns with the normal direction of the rotor surface. As demonstrated in the numerical examples, the proposed method is possible to estimate the clearance between two mating screw rotors with constant or variable pitch, as well as feasible to analyze the meshing clearance between two unconjugated rotors. In addition, differences in the clearance distribution of a variable-pitch screw pair with yaw and pitch misalignments are predictable. These results validate the robustness and flexibility of the proposed method.

Numerical Investigation of a Novel Type of Rotor Working in a Palisade Configuration

This paper explores an interesting approach to wind energy technology, focusing on a novel type of drag-driven vertical-axis wind turbines (VAWTs). Studied geometries employ rotor-shaped cross-sections, presenting a distinctive approach to harnessing wind energy efficiently. The rotor-shaped cross-section geometries are examined for their aerodynamic efficiency, showcasing the meticulous engineering behind this innovation. The drag-driven turbine shapes are analyzed for their ability to maximize energy extraction in a variety of wind conditions. A significant aspect of these turbines is their adaptability for diverse applications. This article discusses the feasibility and advantages of utilizing these VAWTs in fence configurations, offering an innovative integration of renewable energy generation with physical infrastructure. The scalability of the turbines is highlighted, enabling their deployment as a fence around residential properties or as separators between highway lanes and as energy-generating structures atop buildings. The scientific findings presented in this article contribute valuable insights into the technological advancements of rotor-shaped VAWTs and their potential impact on decentralized wind energy generation. The scalable and versatile nature of these turbines opens up new possibilities for sustainable energy solutions in both urban and residential settings, marking a significant step forward in the field of renewable energy research and technology. In particular, it was shown that among the proposed rotor geometries, the five-blade rotor was characterized by the highest efficiency and, working in a palisade configuration with a spacing of 10 mm to 20 mm, produced higher average values of the torque coefficient than the corresponding Savonius turbine.

A thermodynamic computational model analysis of a newly designed Tri-Rotor (T-R) volume air compressor

A thermodynamic computational modelling (TCM) approach is developed to model and simulate thermodynamic processes of a newly designed rotary type air compressor named ‘tri-rotor (T-R) compressor’ using a Lattice-Boltzmann Method (LBM) based fluid flow solution, which is applied for the first time to a rotary compressor flow. With this method, which is combined with a Wall-Adapting Local Eddy-viscosity sub-grid scale stress (SGS) model (WALE), time-consuming classic fluid-domain meshing/re-meshing process is not required and a mesh deformation problem leading to numerical instability is overcome by generating a fixed Cartesian lattice. The proposed TCM approach here is expected to serve as a basis for transient simulations of rotating turbulent and highly compressible flow for accurate and more complete computational representation of an ideal, adiabatic compression process through pressure − rotational angle (P-Theta degree) and volume − rotational angle (V-Theta degree) diagrams. The designed compressor is comprised of three specifically shaped, simultaneously rotating rotors, which are well-positioned in a cylinder to draw and discharge air uninterruptedly through two-suction and two-discharge ports, respectively and achieves higher mass-flow rates with increasing rotational speed. A comparative study with different rotational speeds predicts that high isentropic efficiency ranging from 0.850 to 0.941 can be attained for the investigated rotational speed range without any compromise on mass flow rates and pressure ratios. A proof-of-concept experiment of a full-scale T-R compressor model is conducted to assess its operational feasibility and performance. It is found that the TCM approach reproduces comparable results to those obtained from the preliminary experimental studies.

Performance Analysis and Aerodynamic Design of Axial Flow Compressors

The main objective of the paper is to analyze theperformance of axial flow compressors and to generate asystematic design approach which enables to designsubsonic flow ones. In order to investigate the validity of this approach, the LP axial flow compressor of the RR SpeyMK511 turbofan engine is taken as an example. The designcalculations were based on thermodynamics, gas dynamics,fluid mechanics and empirical relations. The flow isassumed to be of two-dimensional compressible type withconstant axial and rotor blade velocities with a free-vortexswirl distribution. Design calculations includethermodynamic properties of the working fluid, number ofcompressor performance parameters such as, stagetemperature rise and number, flow and blade angles (bladetwist), velocity triangles and relative inlet Mach number atrotor blades tips as well as blades tip and hub diameters. Arepeated calculation is made to determine these parametersalong compressor stages. The variation of velocity whirlcomponents, air and blade angles, deflection and degree ofreaction from root to tip of the blades were also determined.The twist of the blades along the blade length is setaccording to the recommended values in order to obtainsmooth blade twist profile.

Association between the Analytical Technique and Finite Element Method for designing SPMSMs with Inner Rotor Type for Electric Vehicle Applications

This paper focuses on computing the electromagnetic parameters of inner rotor-configuration Surface-mounted Permanent Magnet Synchronous Motors (SPMSMs) via the combination of analytical and finite element methods with an application to electric bicycles. The analytical method is, first, developed in detail to calculate the essential parameters of the inner rotor-configuration SPMSM. Then, a Finite Element Method (FEM) is introduced to verify the analytical parameters found. Further, a simulation of magnetic flux density, torque, cogging torque, torque ripple, back Electromagnetic Force (EMF), linkage flux, and temperature is performed. The end result is validated with a real 2.2 kW inner rotor-configuration SPMSM.

Research on the Characteristics of Figure Round Pattern in Qing Dynasty

Round pattern, also known as round nest pattern. It is one of the most common patterns in ancient China, that is, symmetrical radial or rotating round decorative patterns around. Such patterns are often found on ancient bronze ware, ceramics, weaving and embroidery products, and modern silk fabrics. Round pattern is an important part of the study of Chinese costume patterns, which contains the cultural concepts that Chinese people yearning for perfection, auspiciousness, reunion, harmony and beauty. Cloud bat pattern, rich and noble peony pattern, colorful cloud pattern, sitting dragon pattern, phoenix pattern, butterfly pattern, and so on, the subject matter is numerous. Central symmetry type, Tai Chi type corresponding type, rotary radiation type, asymmetric flower type, and so on, the style is rich. Among them, the Qing Dynasty appeared a round pattern with character stories and relatively free composition. The pattern of the character round has unique characteristics of the Times. On the basis of the aesthetic feeling of the round flower form, it integrates the plot of the characters, reflecting the characteristics of the social customs and aesthetic taste at that time, and establishes a bridge for the traditional pattern and custom illustration.

A New Rotary Magnetorheological Damper for a Semi-Active Suspension System of Low-Floor Vehicles

This study explores the significance of active suspension systems for vehicles with lower chassis compared to conventional ones, aiming at the development of future automobiles. Conventional linear MR (magnetorheological) dampers were found inadequate in ensuring sufficient vibration control because the vehicle’s chassis becomes lowered in the unmanned vehicles or purposed-based vehicles. As an alternative, a rotary type of MR damper is proposed in this work. The proposed damper is designed based on prespecified design parameters through mathematical modeling and magnetic field analyses. Subsequently, a prototype of the rotary MR damper identical to the design is fabricated, and effectiveness is shown through experimental investigations. In configuring the experiments, a proportional-integral (PI) controller is employed for current control to reduce the response time of the damper. The results presented in this work provide useful guidelines to develop a new type of MR damper applicable to various types of future vehicles’ suspension systems with low distance from the tire to the body floor.

Evaluation of The Dispersion Uniformity of Footprint of The Magnus Rotor Type Dispersive Submunition

Dispersion munitions are often equipped with dispersive submunitions used to scatter bombs over a wide area, and one of the types of dispersive submunitions is the Magnus rotor, commonly referred to as a self-rotating flying body. The Magnus rotor is designed to be dispered over a wide area by utilizing the principle of the Magnus effect through self-rotation, and has various trajectories depending on the initial conditions from the mother dispersion munition. In this paper, an index to evaluate the dispersion uniformity of footprint of the dispersive submunition is presented and the dispersion uniformity according to various initial release conditions is evaluated, and it is getting larger with high incidence angle and get max value at certain initial angular velocity.