bluuebunny/crossref_metadata_2025 huggingface dataset:
Validation of theory-based integrated modeling and new insights for a high-performance steady-state scenario with only RF heating on EAST
Authors: Zhai X.M. , Chen J.L. , Xiang N. , Gong X.Z. , Huang J. , Qian J.P. , Xu G.S. , Li M.H. , Liu H.Q. , Zang Q. , Zhang T. , Li G.S. , Wu M.F. , Jin Y.F.
Published: February 2022

Theory-based integrated modeling is validated against high-performance steady-state core plasmas on EAST in the high poloidal beta (β
p) regime with only RF heating. Reasonably good agreement between the modeling results and experimental measurements is obtained not only for the temperature profiles but also for the 11-chord line-integrated densities and Faraday angles for the first time. This validation effort demonstrates that the safety factor profiles can be non-reversed in high β
p experiments on EAST. The inaccessibility for LH waves observed in conventional ray-tracing simulations for some high β
p experiments is effectively mitigated by including the modeling of wave propagation in the scrape-off layer. The observed confinement improvement with density increasing (Gong et al 2019 Nucl. Fusion
59 086030) can be attributed to the reduction of turbulent transport by the collisional stabilization in trapped electron modes, rather than by the Shafranov shift stabilization effect which was proposed to be the major cause of confinement enhancement in previous literature. Based on the successful validation and newly gained physical insights, predictive modeling is performed for core plasma considering the future upgrade capacity of LH wave system and shows that the high-performance steady-state H-mode scenario on EAST can be extended to the regime with q
95 to be ITER relevant.
Numerical simulation of mid-deep geothermal system based on dynamic mesh adaptive finite element
Authors: Ma Zhonghua , Cheng Huiyong , Li Ying , Liu Guixin
Published: February 2022

Numerical simulation is an important tool in the study of geothermal science and even the development and utilization of geothermal resources. Aiming at the development of middle and deep geothermal resources, this paper takes the numerical simulation of U-shaped heat exchange well as the research object. Based on Fourier’s law and heat conduction equation, the dynamic mesh adaptive finite element method is used to simulate the heat transfer process. The results show that the fixed mesh non-adaptive finite element method lacks a feasible error control mechanism, and the adaptive high-order finite element method with dynamic mesh and adaptive time step control can effectively simulate the process of geothermal energy transmission.
Imbalanced Traffic Accident Text Classification Based on Bert-RCNN
Authors: Yuan Shijin , Wang Qixuan
Published: February 2022

Traffic is the signs of urban development, and traffic accidents have a particularly large impact on road conditions. Because traffic accidents are recorded in text, classifying the severity of traffic accidents can not only unify the classification standards, but also greatly help query and prediction of traffic accidents. The frequency of daily minor traffic accidents is much higher than that of serious traffic accidents, so this paper proposes an effective algorithm and model for categorizing imbalanced Chinese traffic accident texts based on severity. Firstly, we establish a standard for refined classification granularity combining expert knowledge, and propose unique accuracy standards to verify the impact of the processed dataset on the model. Then the noise on the dataset is removed, and finally input the text into Bidirectional Encoder Representations from Transformers (BERT) model uses the Recurrent Convolutional Neural Network (RCNN) model as a classifier for fine-tuning. By comparing with the results of other classification methods, it is verified that our algorithm and model have the best accuracy.
Skeleton Action Recognition Based on Double Residual Convolutional Neural Network
Authors: Shi Mengqi , Meng Yue , Yang Wenlu
Published: February 2022

Recently, methods for action recognition using bone point information have gained much attention and research. However, considering the problem, this paper presents a model of skeletal action recognition based on a dual-residual convolutional neural network. The 3D bone data was used as network input to replace the original network structure with ResNet18 network. With action coherence involved, long and short memory network (LSTM) is used to obtain time features for skeletal movement information flow, further improve the fusion strategy, add static attention mechanism to obtain the most important features, and further extract features. With this model, we achieved 85.3% accuracy on the X-Sub of the NTU RGB+D data set, with higher accuracy compared to the original and other networks.
Super-resolution image reconstruction network based on dual-channel pixel attention mechanism
Authors: Zhang Wangwang , Song Anjun
Published: February 2022

In the field of image processing, image super-resolution reconstruction technology based on deep learning is becoming more and more mature. Relying on stacking convolutional layers to expand the depth of the reconstruction network can improve the similarity of the reconstructed image, but as the depth of the convolutional layer continues increase, the learning rate of the reconstruction network will also become lower. In this paper, the dual-channel pixel attention mechanism PA combined with the ESPCN network model can not only retains the high reconstruction rate of ESPCN, but also improves the image reconstruction effect. The experimental results show that the network model proposed in this paper is better than SRCNN, FSRCNN, ESPCN for single image reconstruction, and the peak signal-to-noise ratio (PSNR) and structural similarity ratio (SSIM) are significantly improved.
The Application of BP Algorithm in Optimization of the Supporting Point of Aerial Work Platform
Authors: Zhao Jian , Ma HongFeng , Sun Liang
Published: February 2022

At the moment, the parametric design is used in the design of the supporting point of aerial work platform. With the change of the relative position of the center gravity of each component, it is difficult to provide a great scheme for designer. We need a CAD software to obtain the scheme. The BP algorithm is a neural network algorithm. The mapping relation is obtained by training BP algorithm for the optimization of the supporting point of aerial work platform. When designer input the corresponding design parameters, they can directly get the design scheme.
Skeleton Action Recognition Based on Transformer Adaptive Graph Convolution
Authors: Meng Yue , Shi Mengqi , Yang Wenlu
Published: February 2022

Action recognition is of great significance in the field of machine vision. In recent years, great progress has been made in bone point-based action recognition models, but there is no much research on weak feature extraction of bone, leading to insufficient generalization of the trained models. This experiment proposes to use the Transformer structure and its attention mechanism to extract image features as input to Transformer to capture their behavior after extraction via GCN. Furthermore, the experiments were optimized based on the original ST-GCN model, introducing an adaptive graph convolutional layer to increase its flexibility and add attention mechanisms to a separate spatiotemporal channel module to further enhance the adaptive graph convolutional layer. Experiments on the NTU-RGBD dataset show that the model shows some improvement in the accuracy of action recognition.
Research and Design of Optimal Solution for Network Traffic Anomaly based on Multi-objective Decision Algorithm
Authors: Yan Yiying , Dang Yijie , Zhang Shulin , Li Yang , Li Zhihong , Le Xinyi , Yu Haobo
Published: February 2022

To help maintainers recover from network outages caused by network traffic anomalies, the paper proposes an optimal solution for network traffic anomaly based on multi-objective decision algorithm. It is achieved by combining network traffic anomaly detection with multi-objective decision algorithm, while meeting the objectives of the shortest recovery time, the minimum reduction of security protection and the maximum consistency with the original mode.
Research on the Design of Intelligent Chatbot Based on Deep Learning
Authors: Kuang Chuwen
Published: February 2022

At present, chat robots still have the problems of insufficient utilization of multi-modal information, weak emotion expression ability, and lack of model fusion mechanism. With the application of deep learning in the fields of natural language understanding, word vector representation, machine translation, sentiment analysis, and Chinese word segmentation, people have begun to study the key technologies of chat robots and apply deep learning to chat robots. In view of the problem that the traditional chat robot Seq2Seq model training will produce too safe, common, and repetitive answers to the speech corpus, which affects the interactive experience with users, this paper combines the idea of mutual information to improve the objective function of the model so that the model can produce richer and more diverse answers and give users a better experience. Experiments show that the model has improved many indicators compared with the single-modal model in the microblog data set experiment.
Optimization Design of Camera Pose for Network Base on Multi-view Stereo Vision
Authors: Chen Haomin , Ding Keliang , Qin Chuan , Zhang Pu , Xiao Mingjian
Published: February 2022

When designing a multi-vision stereo vision network, the camera’s positional information has a critical impact on the measurement accuracy. In order to solve the problem of optimizing the camera pose during network design, in this paper, we split the multi-vision stereo vision system into binocular stereo vision system. Based on the mathematical model of binocular stereo vision system, the error function of the positional parameters is constructed. By simulation analyzing the function models the field of view angle, the angle between the optical axis and the baseline, the baseline length, the law of the influence of each parameter on the measurement accuracy and the optimal range of values are obtained. Then we compare the actual measurement results with the simulation analysis results. The results show that as the field of view angle, optical axis and baseline angle, baseline length increases, the measurement error first decreases and then increases, and the increase is gradually accelerated. When each parameter is located in the optimal range, the measurement error meets the precision engineering measurement accuracy requirement of 0.05mm, and the minimum error is reduced by 0.114mm, 0.120mm and 0.061mm compared to the maximum error. In the network design, the optimization of the pose parameters can effectively obtain better pose information of the camera and thus improve the accuracy of the measurement.
Research on the Application of Improved Intelligent DNS in Link Balancing
Authors: Dong Wei , Wan Fucai
Published: February 2022

Based on the analysis of the working mechanism of intelligent DNS, this paper analyzes the defects of intelligent DNS and proposes improvement methods. A precise method for judging terminal address ownership is proposed, a front-end website scheme is designed, technical implementation details are introduced in detail, and online test results are given. The results prove that the intelligent DNS improvement method is effective in link balancing.
Design of a bandgap reference voltage source with low temperature coefficient and high precision
Authors: Zhou Jimin , Xin Xiaoning , Ren Jian
Published: February 2022

This paper proposes a high-precision, low-temperature coefficient, and repair-free bandgap reference power supply circuit. This kind of bandgap reference source adopts the way of double-loop feedback, namely through two amplifiers to clamp the voltage to improve the performance of the circuit. The band gap reference source is mainly composed of four parts, including: band gap reference core circuit, amplifier, start-up circuit and Gaussian current compensation circuit. This article mainly analyzes the working principle of the core circuit of the bandgap reference, and derives the mathematical formula of the circuit. When the power supply voltage is 1.8V, the circuit is simulated in the temperature range of -40°C to 125°C with the Hspice software, and the reference source outputs stably. The voltage is 1.25V±4mv, the temperature coefficient is 3.7ppm/°C, and PSRR at low frequencies is -68dB.
Abnormal Causes and Monitoring Methods of Electric Power Metering Devices
Authors: Lin Zhongai , Zhang Xingyi , Tang Biao
Published: February 2022

Electric power metering device is a necessary device for getting power system operation condition of power supply enterprise and the user information, power metering device management is an important part of the power supply enterprises, directly affect the enterprise’s economic benefit, the cause of the abnormal electric power metering device and the problems, carry out the effective method to implement monitoring for power metering device.
Design of high-performance message middleware based on netty
Authors: Wang Di , Dai YaWen
Published: February 2022

As the number of sensors connected to the IoT cloud platform increases, the incoming data continues to increase, and the server may crash due to excessive traffic. In order to solve this problem and ensure the accuracy of the data received by the server, this paper designs a message middleware based on Netty. Message middleware is widely used in many systems, using message queues to achieve asynchronous communication and traffic peak reduction, and solve the problem of high data concurrency. Compare the mainstream messaging middlewares, select ActiveMQ middleware, design the consumer model according to the characteristics of the protocol, and perform idempotence processing on the consumer side to improve the reliability and security of the middleware.
Research on Automatic Driving Simulation Test System Based on Digital Twin
Authors: Chen Xiaowei , Jin Zhigang , Zhang Qingyu , Li Po , Zhang Sulin , Sun Jiacheng , Tian Xiaosen , Wang Yaofu , Zhang Jian
Published: February 2022

With the rapid development of 5G infrastructure, cloud computing and other technologies to enhance the rapid development of autonomous vehicles. How to quickly, safely and efficiently test and evaluate the autonomous vehicles is the only way for that to have the ability to drive on real public road. This paper build a set of automatic driving simulation test system based on digital twin technology, describing the necessary steps taken for the system design, system implementation, and testing of a autonomous vehicle. In the system the real traffic scene in the digital space re-emerged, to achieve the real vehicle running in the real environment, while mapping to the virtual environment to achieve the vehicle in the loop, making it possible to define driving test scenarios for different types of tractor and trailer combinations and providing the free test site for autonomous vehicles. At the same time, the system provides an open interface, to verify and test various autonomous algorithms. The sensor device of the tested autonomous system is flexibly configured, and the test cost is low and the efficiency is high.
Coordination control of frequency and voltage regulation for renewable energy generation
Authors: Sun Hangyu , Zhang Jian , Li Wenfeng , Wang Hui , Ai Dongping , Geng Zhichen
Published: February 2022

Renewable energy generation has weak disturbance resistance and has insufficient voltage and frequency regulation ability. Aiming at the grid-connected structure of the renewable energy unit converter, this paper analyses the typical control mode of the converter participating in the system voltage and frequency regulation respectively on the basis of the principle and demand of voltage regulation and frequency regulation. Then the practical priority control method is analysed by combining internal active power and reactive power current circle. After that, a coordination control strategy for voltage and frequency regulation is proposed. The strategy optimizes the allocation of active current and reactive current reference value during the operation. It improves the performance of the renewable energy generation, and effectively solves the problems of active power and frequency, reactive power support and voltage, thus enhancing the stability of the power system. Finally, the feasibility of the coordination control is verified by the simulation of permanent magnet synchronous generator in PSCAD/EMTDC.
Key technology and application of primary and secondary fusion power distribution switchgear test and detection
Authors: Wei Jufang , Yao Ying , Feng Junji , Zhang Chi , Yue Yang , Zhang Chunhui
Published: February 2022

In recent years, primary and secondary integration of distribution switchgear has been widely used in the distribution network. In the future, primary and secondary integration will become the mainstream development trend of power distribution switchgear, especially in 2021, the State Grid Corporation of China will issue a new type of primary and secondary integration standardization. The typical design plan of power distribution switchgear have added two configuration methods: electronic transformer and digital transformer. So the traditional independent test method of power distribution automation terminal or power distribution switchgear are no longer applicable to the current new-type primary and secondary fusion standardized power distribution switchgear. At the same time, there is no standard basis for direct reference. This article mainly analyzes the key test items for performance verification of primary and secondary fusion power distribution switchgear, and propose corresponding test detection methods.
Research on GPS Vehicle Navigation System Based on Embedded Technology
Authors: Liu Chen
Published: February 2022

GPS vehicle navigation system is an embedded system commonly used in vehicles, which can optimize the driver’s driving experience and improve the convenience of the trip process. This paper analyzes the application characteristics and architecture of embedded technology. By studying embedded Zigbee nodes, network topology design, node hardware design and node software design, the purpose is to accumulate reliable application data and provide reference for the continuous improvement of GPS vehicle navigation system.
Method of Cogging Torque Reduction for Built-in Permanent Magnet Synchronous Motor
Authors: Yang Yong , Wang Xudong
Published: February 2022

Cogging torque is one of the main factors that deteriorate the performance of permanent magnet motor. In order to reduce the cogging torque of built-in permanent magnet motor, a method of optimizing Rib and DminMag to reduce groove torque of built-in permanent magnet motor was proposed. Firstly, the relationship between Rib and DminMag and groove torque is analyzed through the expression of groove torque. Secondly, the optimal Rib and DminMag were found by finite element parametric calculation, and compared with the pre-optimization groove torque, the groove torque was significantly reduced. Finally, the main performance of motor before and after optimization is not significantly reduced.
Fracture Failure Analysis and Optimal Design of Transmission Gear
Authors: Qiu Shi , Pang Daqian , Li Yong , Li Xunming , Zhao Fuqiang
Published: February 2022

In a special vehicle gearbox planetary transmission mechanism, the sun gear was broken under high-torque and high-speed operating conditions. This paper conducts chemical composition detection, hardness detection, non-metallic inclusion detection, part fracture scanning and other failure causes detection for the failed sun gear, and analyzes the main factors that cause the failure according to the failure characteristics of the sun gear, and proposes improvement measures, which has certain guidance significance.
Experimental study on dressing CBN grinding wheel with orderly arrangement of abrasive sintered Roller
Authors: Liu Zeyin , Zhang Rui , Zhao Huadong
Published: February 2022

In order to improve the CBN grinding wheel in the grinding process of wear problem, adopt the method of soldering preparation and orderly arrangement of sintered diamond wheel on the nap, analyzes the roller surface grinding grain of dislocation in the matrix, and the phyllotaxis configuration mode of the grinding wheel dressing effect, based on the workpiece roundness, after dressing grinding wheel grinding workpiece surface quality and the microhardness of the data analysis, choose the optimal configuration. The results show that the workpiece roundness of matrix arrangement is slightly better than that of dislocation and leaf order arrangement. The surface roughness and 3D surface topography of the workpiece under leaf sequence arrangement are better than those under matrix and dislocation arrangement. The surface microhardness of the workpiece has no obvious difference under the three arrangement modes. Comprehensive analysis shows that the dressing effect of the roller under the arrangement of abrasive grain leaf sequence is the best.
Research on Joint Control Strategy of Optical Energy Storage System
Authors: Li Jing , Wang Xia , Zhu Gejun , Li Rui , Yang Meijia , Wang Fei
Published: February 2022

The energy storage system in photovoltaic power plants has become the main way to solve the current problems, including the volatility and uncontrollability of photovoltaic power generation, as well as improving the performance of photovoltaic power plants and grids. The energy storage system with reasonable charging/discharging strategies can prolong the service life of energy storage system. This article proposes a method based on the combination of optical power prediction technology and low-pass filtering to decompose the output curve of photovoltaic power plants. High-frequency fluctuations and low-frequency fluctuations are respectively stabilized by the BMS control technology of the energy storage system to avoid frequent overall storage batteries. While charging and discharging affect its life, it can also reduce the impact on the grid and voltage fluctuations. It has a significant practical guiding for planning and constructing optical power-storage stations in the future.
Investigating Thermal Stratification in a Hot Water Storage Tank during Charging Mode
Authors: Kumar Kapil , Singh Shobhana
Published: February 2022

Hot water storage (HWS) tanks are the sensible energy storage systems used to accumulate thermal energy in water for later use. In the present study, a vertical cylindrical HWS tank equipped with three heat exchanger coils to harness energy from different energy sources is numerically investigated. A 2-D axisymmetric model is developed in ANSYS Fluent to simulate and study the dynamic behavior of the HWS tank during charging. Three operating cases with one heating source functioning at a time are analyzed to determine the degree of thermal stratification. Transient temperature and velocity distributions are discussed for the qualitative and quantitative analysis of mixing and stratification in each case. The results assist the design engineers and end-users in determining effective modes of HWS operation with maximum stratification, thus, system efficiency.
Design and Fabrication of Thermoelectric Air-Cooling System
Authors: Daniel Chris , Kumar Shukla Anoop , Sharma Meeta , Kumar Phanden Rakesh , Kumar Ojha Manish
Published: February 2022

A thermoelectric air-cooling system (TEACS) is an innovative technology based on the thermoelectric cooling phenomenon. The absence of heavy moving parts to obtain a cooling effect reduces intense vibrations than the traditional cooling system. Moreover, this system is eco-friendly as harmful coolants are not used or produce any harmful elements such as CFCs. The thermoelectric module works on direct current (DC), heating & cooling phenomena depending upon the direction of current flow. Peltier modules are made up of two unique semiconductor materials, such as Bismuth Telluride (Bi2Te3) in the form of pillars sandwiched between a pair of ceramic plates. This paper covers the design and fabrication of an automated thermoelectric air-cooling system. The Peltier module is sandwiched between two Aluminum heatsinks on each side of the Peltier module. Arduino microcontroller is used to provide automatic temperature control. Air is passed through the cold side, and water is used to reduce the heat on the hot side. This system reached 25°C within 300 seconds and 700 seconds to reach 15°C from 30°C ambient room temperature. The novelty of this TEACS has a COP of 1.13 achieved by careful adjustment of electrical parameters with a cooling capacity of 648 W, and the designs are fabricated by using eco-friendly materials.
Effect of duct geometry on thermal management of PCM – Liquid hybrid PV panel
Authors: Bhandari Radhika , Krishna Devanuri Jaya
Published: February 2022

Abstract In this study, a computational fluid dynamics (CFD) model of a PV panel with different cooling technologies is performed. The basic setup consists of a hybrid PV-PCM system, with absorber plate of 0.25m breadth, 0.5m length and 5mm thickness. The study includes the design and simulation of a three-dimensional photo-voltaic model integrated with a water channel and PCM. A commercial CFD tool ANSYS Fluent is used to analyse the thermal transport. The melting of the PCM is simulated using enthalpy – porosity method. Effect of shape and orientation of duct cross-section on the performance of the system is investigated. The cross section dimensions are chosen so as to maintain negligible difference in the volume on PCM. The Reynolds number in each model is maintained constant (Re = 1500) to have similar flow characteristics, so that only the effect of shape on heat transfer can be analysed. Additionally, a PCM-PV model with circular cross-section duct was modelled and compared to triangular, square, rectangular and ellipse cross-section. From the results obtained, it was found that there was a minimum temperature drop of 20oC between simple PV model and PV-PCM model. Triangular shapes had highest thermal efficiencies, with an average of 46%, Square duct showed better electrical efficiency, with an average of 13.25% with same pressure drop as circular ducts. Orientation of duct showed a huge impact on thermal and electrical efficiencies of rectangular channel.
Performance Investigation of Copper and Aluminium Radiators for Lower HP Tractor Engines
Authors: Sharma Megha , Narayan Vishwakarma Prem , Sharma Ajay , Shubham Pritish
Published: February 2022

Development in the design of heat exchangers in past years has taken the demand and usage of radiators to an improved level. Radiators, known as core components of the engine cooling system are now available in many designs and according to the material used. Selection of type of material, whether aluminum or copper is dependent on cost, heat rejection, convection, conduction thermal properties, and many more. Current radiators are either aluminum or copper. Generally, copper radiators are preferred or used in spite of aluminum being cheap and easily available. This paper will compare the performance and analyze both radiators. The objective of the report is to establish a standard material of radiator for various tractor models. Manual Calculation considerations for different variables, MAC (maximum ambient capability), effectiveness, Nusselt number for radiators, and testing of airflow measurement and water flow measurement at different marked points on the radiator will be illustrated with help of suitable test rigs.
Comparative investigation on two tank and cascade thermal storage for solar power plants
Authors: Neelam Khandelwal , Meeta Sharma , Onkar Singh , Anoop Kumar Shukla
Published: February 2022

The use of alternate energy has been increased nowadays due to the environmental threats associated with the fossil fuels. Solar energy is emerged out as the most popular alternate source of energy due to its ease of availability. The energy yield from Solar thermal power project can be characterised as variable because of the daily and seasonal variation of the solar field which directly affects the system efficiency. This concern associated with solar power plants can be eliminated with the use of thermal storage solar energy wherein the solar energy can be stored in daytime and can be releasedin the time no solar irradiations. There is different thermal storage can be used to store solar energy such as sensible heat thermal storage, latent heat thermal storage and chemicalheat thermal storage. The heat transfer fluids play an important role for the selection of thermal storage. The present work compares the performance of two tank thermal storage system and cascade thermal storage system for oil and molten salt as HTF. The efficiency of TES can be attained up to 88.2%with cascade storage which is higher by 7.66%in comparison to the two-tank storage system.
Modelling and analysis of intelligent tyre alternatives for better performance
Authors: Rama Sarma Sri , Chaudhary Vijay , Gupta Dr Sumit , Gupta Dr Pallv
Published: February 2022

For more than ten decades people have been using vehicles rolling on pneumatic tyres. The essential factor for safety of automobile is tyre. Tyre conditional plays vital role in the safety of a passenger. In olden days wheels were made up of wood, later it became evolved into tube and tubeless tyre. A traditional tire is made up of reinforced rubber packed by using compressed air. Conventional tyre over period had been dominating market sector because of its riding comfort and strength. But it has its own disadvantages like problems of puncture, inflation. Under or over inflation of tyre cancause tire blowouts, tread separation. In recent years a few tyre companies and researchers are experimenting with non-pneumatic tyre performance including Michelin, Bridgestone, and goodyear but none of them has started its mass production. Non pneumatic tyres are the tyres which no longer need air pressure. In this project we replace traditional tyre by flexible tyre structure and finds out other intelligent alternatives to conventional tyres. We have investigated spoke’s structure designed for airless tyre and applied uniaxial load. We designed the structure in ANSYS design modeler and ANSYS static structural has been used to analyze whether the designed structure is valid or not. Three kinds of intelligent tyre alternatives have been identified and stressed their use, working and importance for future mobility.
Thermodynamic investigations on PDC based solar air conditioning system
Authors: Masood G. M. , Singh Onkar
Published: February 2022

Global warming is raising the ambient temperature and thus resulting in increased air conditioning requirements. The increase in power requirements of air conditioning systems, in turn, burdens the electricity needs and more electricity generation further adds to global warming. In such situations, the availability of solar energy and its utilization for air conditioning systems appears a potential solution to a certain extent. This paper deals with the thermodynamic analysis of a parabolic dish based air conditioning system working on vapour absorption refrigeration cycle for the H2O and LiBr combination as working fluid. Thermodynamic modelling was used to assess the impact of changing the initial concentration of lean solution and the varying condenser temperature under the atmospheric conditions of that region during peak air conditioning demand months on several parameters such as coefficient of performance, cooling effect, and exergetic efficiency of the system. At 45 percent of the initial LiBr concentration in weak solution, the system’s highest coefficient of performance is attained.
Parametric Investigations on Solid oxide fuel cell and gas turbine combined system
Authors: Kumar Yadav Sanjay , Singh Onkar
Published: February 2022

This paper presents a thermodynamic investigation on the SOFC-GT combined system for maximizing power generation and optimal energy utilization. The system modeling and analysis are based on the first law of thermodynamics. Performance of the solid oxide fuel cell-based system is analyzed for parametric variation of compression ratio, turbine inlet temperature, fuel utilization factor, and ambient temperature. Direct energy conversion system has an advantage over the indirect system as they reduce the adverse impact on the environment, so solid oxide fuel cell-based systems are environmentally friendly. The maximum.output.of.the considered cycle.is 120.08 kW/Kg of air. The combined efficiency of the system is 51.02% at 1400 K.turbine.inlet temperature. and.13 compression ratio at fixed fuel utilization factor of 80%.
Thermodynamic Investigation of ORC Integration in Solar Assisted Gas Turbine Cycle
Authors: Sharma Achintya , Kumar Shukla Anoop , Singh Onkar , Sharma Meeta
Published: February 2022

Worldwide, governments of many countries are worried about global warming due to pollution created by burning fossil fuels to meet energy demand. Nonetheless, they are bothered about the finite availability of fossil fuels on the planet. As a result, it is desirable to reduce dependency on nonrenewable fuels and replace them with renewable energy to meet energy demand. Solar energy is the most cost-effective fossil-fuel replacement. However, the investigators are apprehensive about the resourceful use of solar energy. This led the researcher’s attention to the organic Rankine cycle (ORC), which might be integrated with the standard energy production cycle to make the most of the available energy. The present study performs the thermodynamic investigation of the integrated ORC in the solar-assisted gas turbine cycle. The acquired results reveal that integrated ORC in solar-assisted gas turbine cycle yields an increment in efficiency from 34.57 % to 69.89 % for the solar-assisted gas turbine pressure ratio of 16 bar, the ambient temperature of 300 K with ORC’s pressure ratio of 4 bar, and ORC turbine inlet temperature of 443 K.
Solar preheat with significant Thermodynamics Parameter Scrutiny of Energetic, Economic and Environmental Analysis in Tri-generation System.
Authors: Mani Mishra Krishna , Singh Dr Onkar
Published: February 2022

The solar tri-generation system can enhance the use of solar energy in residences. In this paper, an evaluation of the performance and operating parameters of an absorption sub-cooled compression hybrid cooling (ASCHC) configuration based on the pairing of photovoltaic thermal (PVT) collectors is presented. The work includes the multi-culmination fractionation and chiller originator to the Natural Rankine sequence system to evaluate the critical thermodynamic parameters such as irreversibility ratio, fuel depletion ratio, improvement potential, and total exergy loss of the system. The study was carried out using the first law and second law of thermodynamics applied to each component of each system. Solar absorption-subcooled compression hybrid cooling system (SASCCHC) is a novel cooling system that consistently meets the demand of cooling load with solar irradiance change. It is a very efficient and economical solar cooling system. The hybrid system’s performance is higher due to the improvement of the evaporator temperature of the absorption subsystem. However, SASCCHC is complicated in terms of working process and performance simultaneously due to the coupling of the absorption and compression subsystems. In the prior methodologies, there is a lack of electrical output performances of PVT collectors. It is found that previous studies do not consider the changeable storage tank temperature, exergy destruction rate estimation, and scrutinizing of thermodynamic parameters, which are significant potential. The present work incorporates the parabolic channel collector to estimate the exergy destruction rate, which increases the output working fluid temperature to a wide range significantly. Due to this, the proposed analysis’s outcome proficiently increases fuel depletion ratio and decreases exergy loss.
Design and analysis of Microcontroller based air scrubber using ANSYS CFD
Authors: Singh Shreyas , Tyagi R K
Published: February 2022

The important part for human survival is air the and growing pollution in the environment is a major concern for mankind therefore there is a need for a device is that can remove the gaseous components in the air molecules. With the use of thermoplastic elements, gas-liquid absorption can occur. The concept of scrubber for the absorption of gases was introduced in late 1980 and with the growth of modern techniques, the gas liquids absorption and phase change is been studied for a very long time. A packed column is process equipment, and it is widely used in industries that produce toxic elements. Bed scrubber washing technique for removal of gaseous contaminants to a large extent bus stop with the use of a microcontroller for monitoring the emissions the basic idea of installing this machine in the end or environment for residential and commercial use is a need of the hour. The work relates to the design and performance of the back scrubber and the study of the practical approach results by using it in an indoor environment. The use of IoT in this process is enhancing its quality and we are adding a step towards optimizing the air pollution standards. As the government has taken a lot of efforts for halting the growth of air contaminants by implementing some loss on engine combustion so the work is innovation in the field of air pollution and control.
Geothermal energy-based combined cooling heating and power system
Authors: Kishore Rawat Aditya , Kumar Shukla Anoop , Sharma Meeta , Kumar Singh Ashok
Published: February 2022

This paper studied the geothermal energy-based combined cycle for power cooling and heating purposes. The power system consists of a double flash power cycle, whereas the LiBr-H2O refrigeration absorption cycle is used for the cooling effect. The exhausted geothermal energy from the separator is further utilized for hot water to domestic application in this system. Under the condition of 200°C geothermal water temperature, the overall efficiency of the cycle is coming out 73%, which shows that the heat lost is very less, i.e., maximum heat is utilized in this cycle. The steam turbine work is 759.24 KW, whereas the COP of vapor absorption refrigeration is 0.685, and the leading coefficient of performance of the process is 0.85 working on optimal conditions. The COP of the system increases with an increase in generator temperature, but with an increase in evaporator and condenser temperature, vapor absorption cycle performance decreases.
Weibull Analysis Applications in Unexpected Electrical Breakdown of Ion Thruster
Authors: Zhang X E , Zhang T P , Li D T , Li X
Published: February 2022

The unexpected electrical breakdown (UEBD) of ion thruster is a critical problem. It directly affects the reliability and performance of the ion thruster. The basic UEBD characteristics and Weibull theory are introduced. The self-consistency and applicability of Weibull analysis for UEBD study are discussed. The UEBD period is a proper characteristic variable for Weibull analysis. The approaches to study the factors affecting the UEBD period are presented: (i) distinguishing the effect of coupled factors with the shape parameter of a mixed Weibull distribution, and (ii) studying the effect of a single factor with its respective parameters of the Weibull distribution. The factors discussed include electric field strength, grid material, and ion density. Further aspects to investigate involving the coupling of these factors and mechanisms are prospected.
Numerical Simulation of Hydrofoil Cavitation
Authors: Yin Rui , Liu Heng , He Zhi-Yuan
Published: February 2022

A contrastive analysis was conducted on the lift and drag performance, pressure and gas-phase volume fraction of NACA4412 hydrofoil under different conditions of the cavitation number and the angle of attack based on CFD. The results are obtained as follows: after hydrofoil cavitation, the lift coefficient decreased and the drag coefficient increased with the decrease of the cavitation number, and supercavitation can reduce the drag coefficient locally; the pressure difference between the upper and lower surfaces of the hydrofoil decreased and the cavitation zone on the upper surface became larger with the decrease of the cavitation number; the cavitation zone of the hydrofoil originated from the leading edge; the length of the cavitation zone under large cavitation numbers first increased and then decreased with the increase of the angle of attack, and the zone moved towards the leading edge; the cavitation zone under small cavitation numbers covered almost the entire upper surface of the hydrofoil.
Numerical Simulation of Hydrofoil Cavitation in Pitching Motion
Authors: Yin Rui , Fan Yu-Hang , He Zhi-Yuan
Published: February 2022

Based on CFD, the NACA4412 pitching motion hydrofoil is compared and analyzed for the lift/drag coefficient, the pressure and the gas volume fraction at different attack angles. The result is that the lift/drag coefficient curve of the dynamic hydrofoil is a closed curve. When the hydrofoil is pitching up, the lift/drag coefficient will be generally greater than that in the static state, which first increases and then decreases as attack angles increases. When the hydrofoil is down, the lift/drag coefficient will be generally smaller than that in the static state, which first decreases and then increases as attack angles decreases. Moreover, when the hydrofoil is pitching upwards, there will be a sudden change in pressure on the subsurface, resulting in an extreme value. In addition, there is more comprehensive cavitation on the upper surface of the dynamic hydrofoil, and local cavitation on the subsurface.
Dynamic Analysis and Vibrations Research on Multi-Degree of Freedom Shear Structures
Authors: Dai Pengyi , Yang Shiyue , Ye Shuchen , Tang Zhengheng
Published: February 2022

Vibration is everywhere in of our daily life. This paper studies the effect of rectangular pulse and free vibration on multi-degree of freedom systems. An undamped three-floor shear frame structure subjected to rectangular pulse and a damping three-floor shear building considered free vibration is investigated with respect to natural frequencies, mode shapes, and displacements of each floor level. This paper assumes the three-story shear building structure discussed has orthogonal damping, and the fundamental frequency will not change over time, which means that the mode shape of the system does also not change with time. In addition, the modal superposition method and Duhamel integrals are useful to study the response of the various vibration systems. In this work, it can be concluded that the main response is due to the vibrations’ first mode, even though all its mode shapes can lead to free vibration response. For amplitude of the motion, it will change with the frequency of excitation. When the non-periodic impulse is applied, the forced vibration will be different in the short duration of the impulse with the free vibration phase.
Analysis of the residual stress in additive manufacturing of Ti-6Al-4V
Authors: Liu Junjun , Jiang Hao , Lei Zhenkun , Bai Ruixiang , Yu Shen
Published: February 2022

Minimizing the residual stress build-up in metal-based additive manufacturing plays a pivotal role in selecting a particular material and technique for making an industrial part. However, there are still some limitations for this application, especially the unfavourable final shape and undesired macroscopic properties of metallic parts built in additive manufacturing systems. The distortion or crack due to the residual stress of these parts leads usually to severe problems for some kinds of metal additive manufacturing technology. Therefore, it is necessary to study the distribution of residual stress in the process, which can provide an important reference for the process control of laser cladding. Taking Ti-6Al-4V (TC4) alloy as the research object, a nonlinear sequential thermal mechanical coupling model is established by combining the finite element numerical simulation and experimental deformation measurement. A least squared cost function between the Finite Element Cladding model and the experimental deformation measurement is proposed, and the finite element model updating method is constructed to retrieve the heat source parameters of TC4 Alloy in laser cladding. By comparing the numerical results with the experiment, the rationality of the inversion results of heat source parameters is verified. After that, the stress near the cladding layer is analyzed, and the influence of temperature field on the mechanical field distribution is further studied through the affects of stress distribution.
Modeling and Simulation of mechanical equipment virtual maintenance training collaborative operation
Authors: Ma Yucheng , Xiao Jianbo , Zhang Qiaobin
Published: February 2022

Virtual maintenance technology is a useful supplement to mechanical manufacturing technology. Virtual maintenance training can improve training efficiency, reduce training cost and operating expenses. In order to realize multi person collaborative maintenance training under the maintenance simulation environment, this paper carries out the research on virtual maintenance training collaborative operation modeling and simulation. Firstly, the coordination of maintenance operation process is analyzed, and the operation tasks are reasonably and effectively decomposed according to the structure, function and relationship of maintenance objects; The logical relationship of collaborative maintenance operation is represented by collaborative network operation model; According to the mechanical equipment maintenance process and the characteristics of multi-agent, a hybrid cooperation model based on the role and multi-agent is constructed; In order to realize the concurrency control of collaborative operation, according to the logical relationship between tasks and resource constraints in the working environment, the locking method is used to control the execution of maintenance tasks; The mechanical equipment virtual training and assessment platform is constructed to realize the functions of disassembly process training, operation learning and process discussion.
Study on the compression and shear bearing capacity of composite stiffened plates with opening crack
Authors: Liu Yan , Zou Jianchao , Zhu Rongxin , Lei Zhenkun , Bai Ruixiang
Published: February 2022

In the process of manufacture and use, the composite stiffened plate will degrade and produce different types of cracks and damage, which limits its application. Therefore, it is significant to study the composite stiffened plate with cracks. Three-dimensional Hashin failure criterion and the gradual damage model of TAN parameter degradation are applied to simulate composite stiffened plate with long crack under uniaxial compression and pure shear load. The effects of crack angle on the ultimate compressive strength, shear strength and progressive damage of composite stiffened plates were investigated. The results show that the effect of crack angle on the compression performance of the stiffened plate is not simply linear, but the effect on the shear performance of the stiffened plate is more complicated, and The effect of crack angle on shear behavior is also related to the sequence of layer.