bluuebunny/crossref_metadata_2025 huggingface dataset:
The influence and optimization of air distribution method on the boiler burns high-sulfur coal
Authors: Liu Honggang , Lu Shaobo , Song Zhiyu , Liu Xiu , Wang Ning , Han Jiting , Zhao Mingliang , Jiang Weiwei , Guo Shuai
Published: February 2022

A large amount of H2S will be generated during the operation of power plants mixed combustion with high-sulfur coal, causing high-temperature corrosion of the boiler water-cooled wa ll. In order to prevent it from pipes bursting due to high temperature corrosion during the operation of the unit, Air distribution was adjusted on a 350MW subcritical pulverized coal combustion boiler, especially for the opening of the secondary a ir valves of each layer of the burner, so as to reduce the volume fraction of H2S in the furnace and lower the corrosion of the water-cooled wall. The research results show that by adjusting the a ir distribution, the volume fraction of CO and O2 in the flue gas of the furnace is changed, and at the same time, it also has an influences on the change of the flue ga s temperature in the furnace, a nd effectively inhibits the generation of H2S, a lleviating the high temperature corrosion of water wall.
Study on the variation law of hydraulic jump values of pumping well in the loess aquifer
Authors: Zhang Xuezhen , Huo Aidi , Wang Jucui
Published: February 2022

This study aimed to investigate the influencing factors for the water jump and the research status of the solution. Using the in-situ pumping test, the analytic solution method, the curve-fitting method, and the method for determining the water-level difference of the main and auxiliary wells were put forward to calculate the characteristics of the water jump under the condition of constant flow. The water jump values obtained by different methods were compared. The duration change of the water jump value under three constant-flow pumping conditions was analyzed. Also, the relationship between the water jump value and the duration of the flow rate under three unstable flow conditions was examined. The results showed that, with reference to the analytical solution of the jump value, the value calculated by the difference method of primary and secondary water levels was about 17% and that calculated by the curve-fitting method was about 10% under the condition of constant-flow pumping. When the pumping amount increased to a certain value, the jump value was stable in a certain period of time. When the pumping volume increased to a certain value, a linear relationship was found between the pumping volume and the water jump value for a certain period of time under the condition of unsteady-flow pumping, but this relationship did not repeat completely. The results showed that it was difficult to calculate the magnitude of the water jump under the in-situ test strip. Further, the method for determining the water-level difference between the main and auxiliary wells could be used to approximate the water jump of the pumping well. It was confirmed that a linear relationship existed between the water jump value of the main well and the pumping amount under certain conditions during the pumping process. This linear relationship was affected by various factors and did not always exist.
Research on construction method and information system of double prevention mechanism in iron mine
Authors: Liu Yejiao , Teng Ting , Chen Ying , Xing Hui , Cui Yinuo , Zhang Peng , Wang Puxian
Published: February 2022

At present, there are many problems in the construction process of the double prevention mechanism in iron mine, such as unclear construction steps, disconnection of construction process, and deviation of construction priorities, et al. Based on the PDCA cycle mode and the improved risk assessment method for working conditions, the construction method of double prevention mechanism in iron mine is analyzed and studied. The yaahp meta-decision software (Analytic Hierarchy Process software) is used to determine the weight of hazardous factors and their corresponding control measures.The concept of “failure frequency” is put forward and the calculation method of accident probability (L) is modified to realize the accurate hierarchical control of accident risk; At the same time, the failure of control measures is defined as “hidden danger”, and then the transmission mechanism of hidden danger investigation and management and risk grading management and control is established.The “Information management system of double prevention mechanism in iron mine” is developed by adopting the B/S structure to realize the informatization of the double prevention mechanism construction. According to the above methods and steps, the double prevention system of iron mine can be reasonably established to effectively identify risks and control hidden dangers and provide favorable guarantee for the safe production of iron ore.
Ice thickness estimation method of overhead line based on distributed optical fiber temperature sensing
Authors: Zou Xiaoming , Liu Xinzhan , He Yi , Lan Yingbin , Yang Liuhui , Zhao Lijuan
Published: February 2022

In order to monitor icing condition of overhead line based on distributed optical fiber temperature sensing, the transient temperature field models of radial and axial heat transfer for iced overhead line are constructed. The finite element method is used to solve the model to obtain the axial and radial temperature distribution inside the overhead line. Based on the two models, the change of the optical fiber temperature with time when the ambient temperature changes at a certain rate is investigated. At the same time, the change of optical fiber temperature with time in the iced and uniced sections under different ice thicknesses is also investigated. On this basis, the change of temperature difference with time is investigated. The formula of ice thickness estimation according to the temperature difference between iced and uniced sections’ optical fibers is obtained. This work lays a foundation for the evaluation of ice condition of overhead line based on distributed optical fiber temperature sensing.
Research on influencing factors of cable traction force in horizontal directional drilling
Authors: Tang Jipeng , Qin Tao , Zhang Haiwei
Published: February 2022

Horizontal directional drilling and pipe pulling technology is playing an increasingly important role in power engineering applications because of its low social and environmental impact and high construction speed. However, due to the more complex urban underground pipeline environment and the uncertainty in the process of cable pulling and laying, in order to ensure the safe laying of cables and later operation, so the cable traction force verification in the process of pulling is particularly important. Relying on specific engineering examples and relevant regulations and specifications, the cable traction force formula in the process of pulling the tube is studied, modified and given its arc-making section equivalent model, the selection principle of the discriminative cable traction method, and the influencing factors affecting the safety coefficient of cable traction force are studied.
Study on disaster prevention system in key areas of urban forest park with multi-factor coupling-- Chengdu Longquan Mountain as an example
Authors: Zhou Xuehong
Published: February 2022

Urban forest parks are major ecological sites in the suburban areas of large cities with good forest vegetation and forest ecological environment, providing people with recreation, tourism, fitness and other suburban activities, and are an important component of the urban landscape system. The spatial density and development intensity of people, facilities and places in the park are higher than those in general forest areas, and the risk of forest disasters is high. To effectively prevent the occurrence of forest disasters and ensure the safety of touring, this paper takes Chengdu Longquan Mountain Forest Park as an example, and divides the key areas of the forest park into high risk areas, medium risk areas and low risk areas through coupled analysis of forest fire risk factors, forest pest risk factors and geological disaster risk factors, and builds a system of prevention, prevention, resistance and rescue for different risk levels. The system is a combination of prevention, resistance and rescue, with points leading to lines, and lines leading to surfaces, forming a disaster prevention system that combines “points, lines and surfaces”, with human, physical, technical and institutional prevention complementing each other, providing a model for reducing the risk of disasters and ensuring the health and safety of forest parks.
Identification for water quality based on color characteristics
Authors: Wang Jiangang , Zhai Zhengang , Zhu Yunya , Zhang Li , Fang Xusheng
Published: February 2022

It’s great significance for protection of water ecological and water resources to identify water quality rapidly and conveniently. In the past time, water quality was test and monitored with traditional laboratory methods, which was hard to meet the requirements of urgent demand. A rapid and convenient method for the identification of water quality based on machine learning was used in this study. By sampling and photographing, the image of water was acquired. Then nine dimensional digital information features of the color information were obtained by the moment method. Based on the historical data and expert experience, a support vector machine (SVM) model was successfully built and well trained. Then the model was verified with the test data, and the accuracy reaches 95%, which proves this method has good effect and high precision. This work will generate fresh insight into water quality identification and contribute to water resources protection.
Design of energy-saving greenhouse automatic irrigation system
Authors: Guo Yaqin
Published: February 2022

In view of the urgent need of the greenhouse irrigation, a Energy-saving greenhouse automatic irrigation system is designed. The system is powered by solar energy and controlled by Single Chip Microcomputer. Multi-point humidity sensor is used to detect soil humidity. An intuitive system management platform is also provided to complete data processing. The information management software was developed for real-time monitoring and remote alarm monitoring. The experiment show that the system can realize the automatic irrigation function, when the soil humidity decreases to the lower threshold of soil humidity, the system starts to work, and when the irrigation reaches the upper threshold, the system can stop irrigation within 10min. The system is easy to operate and stable operation. It also has certain value of application. The development and use of this system can offer experience and technical support to the establishment of intelligent irrigation systems.
Risk assessment of high slope landslide in open-pit mine based on comprehensive geophysical prospecting
Authors: Zhao Zihao , Lyu Haijian , Kang Sen
Published: February 2022

The landslide of high slope of open-pit ore rock poses a great threat to the safe production of open-pit mine and seriously affects the economic benefits of the mine. The risk of landslides for the mines where landslides have occurred should be assessed in order to avoid similar accidents. The mechanism of landslide in area C of Bayan Obo’s East mine was studied, and the comprehensive prospecting of seismic method, geological radar method and high-density electric method was carried out on all areas of the main east mine without landslide reinforcement. On the basis of comprehensive prospecting results, five indicators affecting slope stability, such as water content and fault combination mode, were selected. By making pairwise comparison between these five factors, the judgment matrix was constructed, and the weight matrix of each factor was obtained by transforming the judgment matrix. Based on experience and parameter sensitivity analysis, these indexes were divided into three levels: high risk, medium risk and low risk, and the degree of correlation between each factor and evaluation was calculated. Taking a section as an example, the gray fuzzy matrix and weight matrix were constructed, and the gray comprehensive fuzzy judgment was carried out to determine the landslide risk level of the section.
Blockchain-based big data forecasting system for the marine environment
Authors: Han Luyao , Shi Xiaoxiao , Dong Mingmei , Wei Guanghao , Song Xiao
Published: February 2022

In response to the difficulty in sharing and low utilization of marine forecasting resources such as marine environment data, marine environment big data forecasting methods and marine environment forecasting products, the author proposed a blockchain system architecture consisting of data layer, network layer, transaction layer and application layer. Based on key technologies such as FISCO alliance chains, incentive mechanism and smart contracts, a marine environment big data forecasting system is developed in order to manage marine environment data and marine forecast products such as measured data, marine information products, sea surface temperature, sea surface height, 3D thermohaline circulation, typhoon tracks, and red tide occurrence rate on the chain. The system is able to achieve the decentralized common maintenance and trusted data sharing of marine forecast resources. It also promotes the development of marine environment forecasting technology, and provides a concrete and workable solution for the integration of blockchain and marine technology.
Association plant leaf longevity to the increasing warm and arid environment
Authors: Zheng Xiaofeng , Chen Jiping , Sun Jiarui , Ren Rui
Published: February 2022

The longevity of plant leaves is an important factor relating to their growth strategies and responding to global climate change. The focus of this study is to present a meta-analysis of leaf life spans through an extensive literature survey. As to our knowledge, no comprehensive synthesis has yet been presented to reveal the response of leaf longevities to changing external abiotic factors, including elevated levels of carbon dioxide, increasing temperatures and shorter availability of moisture. We screened 146 abstracts from the Web of Science and summarized the results of 78 specific studies dealing with plants leaf longevity including herbaceous, shrub and tree species. The reaction of tree species was assessed in field studies while shrub and herb species were studied under experimental or field conditions. The leaf longevities of tree species are most affected by elevated levels of CO2, but not by the other two factors. Shorter leaf longevities of herbaceous species are observed in response to rising temperatures and greater moisture levels. Shrub species did not show significant changes in leaf longevity responding to any of the studied external factors. Herbaceous species were more affected by combined changes in temperature, moisture, and CO2 than shrub and tree species. In view of the whole plant biome, there are no significant responses, neither.
Assessment of flood control and water environment considering river construction project in a typical coastal city
Authors: Fu Lei , Wang Junmin , Wu Changhuai , Xu Haibo
Published: February 2022

With the acceleration of industrialization and urbanization, the flood control ability and water environment of most Chinese coastal cities become worse than before, the current river network water system layout and river scale can no longer meet the regional flood discharge and drainage requirements. Yuhuan city is a typical coastal city located close to the east offshore area of China, which also suffered from the flood control and water environment problems. According to the planning reconstruction project of river network in Yuhuan city, the layout of river networks will transform. In this study, a river network model is introduced to simulate different conditions of the planning project. A comprehensive study of flood control and water environment method is utilized in order to ensure the regional water security and social development.
Practical analysis of cleaning water supply pipeline using air and water flushing technology
Authors: Yuan Wenqi , Chen Feng , Ding Jie
Published: February 2022

To ensure the safety of water quality, pipe network cleaning and security management are put forward higher requirements. Traditional single-phase water flushing pipe technology requires high velocity and large flow rate of water, which does not suitable for large-diameter pipes. Air and water flushing pipes are new pipeline cleaning technology, which has high efficiency, good washing effect, and can save a lot of water. The principles of airwater flushing large-diameter, large-deviation-elevation, and many- ups-and-downs pipes are described in this paper. Based on the two-phase flow theories, it analyzes complex hydraulic characteristics and control parameters for flushing pipeline. Combine with engineering practice, air and water flushing diameter of 800 mm pipeline in Shanghai city and flushing pipe parameters are introduced. The air and water flushing effect and water resource consumption reduction are analyzed, as well.
Study on rock breaking efficiency of special shaped cutters
Authors: Peng Qi , Zhou Yingcao , Yu Jiaqing , Yang Xiongwen , Liu Yu , Ma Chi , Cheng Chris , Ke Xiaohua
Published: February 2022

The optimization of cutter shape has become one of the main innovation direction of PDC bit technology. At present, both domestic and foreign bit manufacturers have put forward various special shaped cutters to improve rock breaking efficiency. However, there are relatively few researches which focus on the rock breaking efficiency of special-shaped cutters. Therefore, three kinds of typical cutters (flat cutter, convex cutter and concave cutter) are selected as the study object in this paper. Based on the single cutter test, the relationship of axial cutting force, cutting area and cutting specific energy under different working conditions will be provided. The experimental results show that the axial cutting force and specific energy of concave cutter and convex cutter are lower than that of flat cutter in most test cases. The results are almost the same for both Vosges sandstone and Marcellus shale cases. In other words, the tested concave cutters are easier to intrude into rock and obtain higher rock brea king efficiency under the same cutting conditions, when compared with flat cutter and convex cutter. The experimental method provides a technica l reference for studying the rock breaking efficiency of three-dimensional cutters with different shapes.
Distribution characteristics of bacterial communities in photovoltaic industrial parks in Northwest China
Authors: Wu Wei , Yuan Bo , Zou Penghui , Yang Ruoting , Zhou Xiaode
Published: February 2022

Despite the rapid development of the green energy industry represented by solar photovoltaic, its ecological and environmental effects cannot be ignored. There were few reports on the impact of photovoltaic power station construction on soil bacterial community variation. In this study, the community abundance, diversity, structure, and distribution characteristics of soil bacterial in Gonghe photovoltaic power station, Qinghai Province were analyzed using quantitative Polymerase Chain Reaction techniques and Illumina MiSeq sequencing of the 16S ribosomal RNA gene. Quantitative PCR assay showed that the average16S rRNA gene copy numbers of bacteria in the soil were 8.04×109copies per gram dry soil, which was significantly affected by the physicochemical properties of the soil. Illumina MiSeq sequencing illustrated that Actinobacteria (30.04%), Proteobacteria (29.38%), Firmicutes (2.69%), Bacteroidetes (1.51%), and Chloroflexi (1.07%) were the major phylum of soil bacterial communities, while Rubrobacter (2.51%) and Streptomyces (2.38%) was the main genera. The beta diversity indices of samples assessed via non-metric multidimensional scaling and cluster analysis indicated that the construction of a photovoltaic power station had no significant impact on the soil bacterial community structure. In addition, statistical product and service solutions and redundancy analysis demonstrated that the bacterial abundance and diversity were mainly regulated by soil water content, electrical conductivity, and other environmental factors. This study was the first time to analyze the spatial change of soil bacterial community in the desert under a photovoltaic field, which was of positive significance for the future assessment of how human disturbance affects the plant-bacteria-soil relationship in the desert ecosystem.
An algorithm for rapid ground surface mesh generation used in complex terrain wind field simulation
Authors: Zhao Fan , Zhang Fugang , Chen Bo , Qi Chen , Zhang Jian
Published: February 2022

In the study of wind engineering problems, it is of considerable importance to obtain accurate surface wind field characteristics. Surface features have significant impacts on the characteristics of small- and micro-scale wind field, so the fine reconstruction of terrain features is the basis of small- and micro-scale wind field simulations. However, since the GIS data obtained by satellite scanning cannot be directly used for CFD numerical simulation, the geographic information data is usually of considerable amount and contains a large number of waste points, thus difficult to be completed by manual modeling. To solve this problem, an automatic waste point repair algorithm and a grid aggregation method based on greedy algorithm are proposed, which can quickly and efficiently reconstruct the surface and generate the grid. Relying on the national numerical wind tunnel project and integrating the above core algorithms with the pre-processing and post-processing modules, a general and efficient surface mesh generation software ESM (Earth Surface Mesh) has been developed. Compared with the surface modeling and grid generation modules provided by other software, ESM has more comprehensive functions, and surface grid rapid generation technologies such as waste point data processing, grid adaptive refinement based on elevation change, high fidelity interpolation technology and partition splicing generation. It supports more interfaces and can generate structured and unstructured grids. The preliminary example shows that the surface grid generated by ESM meets the needs of wind engineering simulation.
Research on optimal maintenance cycle model of nuclear equipment based on left and right fuzzy sorting method
Authors: Liu Na , Zou Shuliang , Huang Binhai
Published: February 2022

For the nuclear equipment with high reliability, the optimal maintenance cycle model of nuclear equipments is established by balancing the relationship between working time before component failure and maintenance cost. According to the expert evaluation, the failure of the equipment is analyzed. In the study, the ridge membership function is improved, and the failure probability model is established by using the left and right fuzzy sorting method. It transforms the fuzzy number into the fuzzy probability, so the component fault distribution function is determined. By testing, the model has good applicability and sensitivity. Taking the spent fuel shearing machine as an example, the optimal maintenance cycle of the key parts of the shearing machine is calculated. The results are consistent with the actual conditions, which can provide the basis for the formulation of the nuclear equipment maintenance plan. The results of the study show that the proposed method is of great significance for improving the reliability and maintenance efficiency of nuclear equipment.
Preparation and performance study of V2O5/TiO2 catalysts supported on ceramic filter
Authors: Shen Chen , Zheng Quanjun , Wang Xiaodong , Zhao Jie , Liu Changrui , Lv Haiyang , Dong Changqing , Hu Xiaoying
Published: February 2022

As the country pays more and more attention to air pollution, the ceramic filter catalyst that can achieve the effects of dust removal and NO reduction simultaneously has a promising prospect. In this paper, ceramic fiber filter supported catalyst was prepared by impregnation method and tetrabutyl titanate method. The effects of vanadium content, space velocity, temperature, and tetrabutyl titanate concentration on the NO conversion of ceramic fiber catalysts were studied, and various physical and chemical methods were used for characterization. The results show that ceramic fiber had excellent multi-dimensional space and bridging structure. The NO conversion of impregnation catalyst and tetrabutyl titanate catalyst increased with the increase of vanadium content and tetrabutyl titanate concentration; At 6700h−1 and a temperature of 300°C, both catalysts can reached the highest catalytic efficiency, tetrabutyl titanate method catalyst was 93.67%. The tetrabutyl titanate catalyst can be loaded more evenly and the filtration pressure drop of the catalyst was smaller than that of the impregnation catalyst. The filtration pressure drop was increased by about 20% compared with the unsupported ceramic fiber.
C/S-TiO2 nanospheres with enhanced visible-light response for formaldehyde degradation of particleboard
Authors: Lei Chao , Chen Meilan , Zhong Naifei , Yao Weihui , Xiong Yudong , Zhang Xiangyu , Lu Chenxi
Published: February 2022

C/S-TiO2nanospheres (CSTN) were prepared using a template-free solvothermal method. The size, shape and composition of the as-synthesised CSTN were investigated by transmission electron microscopy, X-ray diffractometry, energy-dispersive X-ray spectroscopy and electron probe microanalysis/wavelength dispersive spectroscopy. Elemental analysis revealed that C and S atoms were favourably doped into the TiO2. The photocatalytic oxidations were investigated in a simulated environment, and the catalytic activity was assessed by degrading formaldehyde emitted from particleboard under visible-light irradiation. A maximum degradation efficiency of 92.8% within 80 min indicated an excellent photocatalytic performance of the CSTN.
Physical and MAC layer simulation of IEEE 802.15.4c protocol in transformer terminal unit
Authors: Yang Qingsheng , Wang Fuliang
Published: February 2022

IEEE 802.15.4c protocol is suitable for large-scale process control applications with ultra-low complexity, low cost and low power consumption. It is particularly suitable for wireless communication standard used in TTU (transformer terminal unit). Based on the introduction of IEEE 802.15.4c protocol, the physical and MAC (media access control) layer simulation program of IEEE 802.15.4c protocol in TTU is written in MATLAB. In the program, the Gaussian noise with different SNRs (signal-to-noise ratios) is used to simulate noise of signal, and the spread spectrum O-QPSK (offset-quadrature phase shift keying) is used to modulate signal. Based on this, the process of signal generation, signal transmission and signal reception is simulated. The influences of SNR, threshold of sliding autocorrelation method and order of filter on BER (bit error rate) are investigated. The results reveal that the BER of simulation is significantly lower than the theoretical value, and the former is only about 2/5 of the latter when the SNR varies from -2 dB to 6 dB. The threshold of sliding autocorrelation method has a big influence on BER. The threshold corresponding to the minimum BER ranges from 0.4 to 0.6. The order of filter has little influence on BER.
Evaluation suitability of Guanzhong land for green and selenium-rich planting
Authors: Ji Huawei , Ren Rui , Li Aorui , Chen Jiping , Qiao Xinxing , Zhang Yali
Published: February 2022

To carry out the suitability evaluation of green and selenium (Se)-rich planting in Guanzhong area, 74 maize plant samples and 74 rhizosphere soil samples were collected. Our results showed that all soils in the Guanzhong area were clean and pollution-free, but only cinnamon soil and alluvial soil can be divided into green Se-rich land. Moreover, there is safe and no heavy metal exceeded standard in maize seed samples in the Guanzhong area, but only Se content of maize seeds grown in cinnamon soil and alluvial soil reached the Se content standard of Shaanxi Se-rich food (> 0.05 mg/kg) according to soil environmental quality standard, the national standards for food safety, natural selenium-rich land demarcation and identification, and Se-rich food standard of Shaanxi province. These results indicated that cinnamon soil and alluvial soil in the Guanzhong area was very suitable for planting natural, green and safe Se-rich crops.
Complaint electricity customer clustering method based on electricity big data
Authors: Zhao Beibei , Li Lu , Zhang Jiajia , Feng Jingyu , Xia Lipeng , Liu Jingye , Yu Yongxing
Published: February 2022

In the fierce domestic market competition, the improvement of service quality is an important goal of electricity companies. This paper proposes the k-means algorithm based on the improved wolf pack algorithm, which is suitable for the power company complains, there are many factors that affect user complaints. Firstly, the PCA method is used to reduce the dimension of the complaint user’s behavior influencing factors, so as to improve the accuracy of clustering. Secondly, due to the shortcomings of falling into local optimal solution and low clustering accuracy, this paper proposes an improved wolf pack algorithm, which proposes the interactive strategy of walking behavior, calling behavior and an adaptive siege strategy for behavior, the clustering accuracy and convergence speed are improved.This algorithm overcomes the shortcomings of the original algorithm. Moreover, it improves the efficiency and clustering quality of the algorithm and it can realize the accurate classification of users.
Temperature prediction of substation equipment based on back-propagation neural network -simulated annealing
Authors: Wang Yong , Bai Ruxin , Li Weixin
Published: February 2022

The substation is an important part of the smart grid. The stable operation of electrical equipment in the substation is related to the stability of the grid. According to the statistical results, among the common substation equipment failures, thermal failures have a larger proportion. Thermal faults can be monitored through the surface temperature of the equipment, and predicting the changing trend of the equipment temperature in advance is of great significance for reducing equipment faults in substations. For this reason, this paper proposes a method for predicting the temperature of substation equipment based on BP neural network-simulated annealing algorithm, using equipment parameters, environmental information parameters, etc. to predict the temperature of electrical equipment in the substation, so as to realize early warning of thermal faults in substation equipment. Through comparative analysis, it is verified that the method proposed in this paper can accurately predict the temperature of substation equipment, which provides strong guarantee and support for the safety management of substation electrical equipment.
A master-slave game model of power trading in cross-regional spot market
Authors: Zhang Ye , Wang Rongmao , Zhang Jian , Liang Xiaohe , Hui Xuan
Published: February 2022

In order to solve the multi-agent equilibrium of the cross-regional power transaction, a master-slave game model considering multi-agent equilibrium is constructed with the ultimate goal of maximizing the sum of the benefits of all parties in the cross-regional power transaction.
Cooperative optimal configuration of integrated energy system considering uncertainty factors of source-load
Authors: Li Tong , Sun Heyang , Shi Zewen , Li Qingchun , Zhang Jian , Huang Bonan
Published: February 2022

Existing studies have focused on the source-load uncertainty in the integrated energy system (IES), but ignored the impact of the integrated demand response (IDR) uncertainty. Therefore, this paper comprehensively considers the uncertainties of renewable energy, load and IDR, and proposes a two-layer optimal and configuration model. In addition, non-parametric density estimation and Copula theory are combined to improve the traditional source-load uncertainty probability model. Meanwhile, based on the double uncertainty of baseline load and price elasticity coefficient, interval fuzzy calculation method is proposed to modify the elastic coefficient. On this basis, aiming at the minimum annual comprehensive operating cost of the system, the configuration of energy hub equipment was solved in layers. The calculation results show that including IDR in configuration calculation helps to suppress the net load curve of the system, reduce the influence of user energy and intermittent power output uncertainty on system configuration results, and make the system run economically and environmentally.
ELADINE: sensor monitoring and numerical model approach for composite material wing box shape distortions prediction
Authors: Torre-Poza A , Pinto A M R , Grandal T , González-Castro N , Carral L , Travieso-Puente R , Rodríguez-Senín E , Banu C , Paval A , Bocioaga M , Firtat L
Published: February 2022

Out-of-Autoclave technologies are emerging as cost-effective alternatives to autoclave cure prepreg. However, their implementation in aerospace industry is still presenting many challenges. A common problem is the shape distortions that results in geometry mismatches with the tool. A way to avoid this and ensure a good final quality part is identifying the mechanisms that induce these deformations and optimize the manufacturing process of each component with the aim of reducing the production of faulty parts. The main objective of ELADINE project is to provide a method for shape distortions prediction on composite integral structures using an experimental-numerical approach. Different manufacturing parameters were monitored using Fiber Bragg Grating (FBG) sensors and DC-dielectric (DC) sensors and the resulting part geometry was examined by means of 3D coordinate analysis. The study performed for LRI (Liquid Resin Infusion) manufactured parts and the scenarios considered for the calibration of a Finite Element Method (FEM) based simulation tool are presented in the article. The resulting model will be implemented in a sub-scale demonstrator and, eventually, in a full 7-meter composite wing-box.
Design against distortion for aerospace-grade additively manufactured parts - PADICTON
Authors: Omairey Sadik L. , Loukodimouf Vasiliki , Sampethai Sofia , Bahrami Faranak , Kazilas Mihalis , Salamat-Zadeh Farshad
Published: February 2022

Additive manufacturing (AM) is a computer-controlled 3D printing process with increasing demand in the aerospace sector. This manufacturing process offers the production of lighter components, design flexibility, reduced labour effort and material cost, as well as decreased waste generation compared with subtractive manufacturing. Additionally, AM can provide parts availability at the point of use, significantly improving the supply chain. However, producing advanced high-temperature AM thermoplastic components remains a challenging task as these require a high-temperature build chamber environment that is prone to producing parts with thermal stresses and warpage. PADICTON project aims to develop a tool capable of accurately and rapidly predicting and correcting such distortions, offering improved quality of the produced parts and minimising rejection rates. Creating this tool requires conducting a comprehensive mechanical and thermal characterisation campaign to optimise the print parameters and part geometry. In this study, the concept of the project and the findings of the initial mechanical and optical characterisation tests for two AM processes, namely fused deposition modelling and selective laser sintering, are presented and discussed.
Design methods and manufacturing techniques applicable in constructing dynamically scaled airplane models
Authors: Olejnik A , Rogólski R , Milczarczyk J , Szcześniak M
Published: February 2022

The article describes methods and techniques intended for designing and manufacturing scaled airplane models applicable in experimental flight testing. Reduced model with resized geometric dimensions should be constructed in such way to preserve similarity of its structural properties with properties of the real aircraft. Having kept the similarity of weight, stiffness and aerodynamic load distribution and maintaining properly scaled values of thrust-to-weight and wing loading ratios we can prepare scaled model showing in-flight features identical to the real airplane.

A series of measuring and technological activities have to be undertaken to develop full CAD model mapping airframe geometry and structure of the real aircraft. The process chain includes measuring, design and technological activities. The development of the geometry model includes: scanning outer geometry of the real airframe, development of the surface geometry model in the CAD environment and then introducing inner geometry items which together with outer skin face make a completely assembled model of the aircraft. For the needs of constructing scaled model the full-size CAD model has to be reduced. The structure of that resized model do not have to be the same as the real one. Materials and structural elements can be quite different but after assembling them the similarity of static and dynamic structural effects should be proved. Within the manufacturing phase there are some necessary stages like preparing molds for laminating components, milling solid elements, assembly of structural components, surface finishing of the model-body surface. The final model was subjected to a load test in a special test stand to check its deformability under specific load. In the same way the numerical static analysis of the full-size FEM model was conducted. The distribution of static displacement results obtained in both cases were compared. The other way of checking structural properties of the scaled model is comparable analysis of resonant vibrations. However, in this case, vibration measurements were not carried out and model verification stopped on a comparative analysis of construction mass distribution.

The procedure and results were elaborated on the example of the Tu-154M aircraft, of which the reduced model was developed in the Faculty of Mechatronics, Armament and Aerospace of the Military University of Technology (FMA MUT Warsaw, PL). Constructing and testing dynamically scaled model is one of many tasks solved in the framework of complex research project, of which the general purpose was to give numerical and experimental results useful in explaining the circumstances of the Smolensk disaster.
Jig-less end-effector system for automating exhausting composite fuselage assembly tasks
Authors: Blanco Elena , Omairey Sadik L. , Luque Rafael , Barrientos Jose Maria , Ferrera Eduardo , Kazilas Mihalis
Published: February 2022

In this study, the jig-less end-effector system developed to assemble components of a full-scale multifunctional integrated composite thermoplastic lower fuselage section is tested and validated. To offset the environmental impact of higher volume of air transport, the aviation industry wants to design lighter and more environmentally friendly aircraft. To achieve this, there is a need to exploit novel materials and technologies. Advanced thermoplastic composites provide an excellent material option thanks to their weldability, low density, low overall production cost, improved fracture toughness and recyclability. However, to fully appreciate their capabilities and benefits, new manufacturing approaches and techniques are needed. Hence, projects such as TCTool, “innovative tooling, end-effector development and industrialisation for welding of thermoplastic components”, aim to develop innovative tooling and end-effector systems for the assembly of a multifunctional thermoplastic fuselage. This study presents the development, operation, and testing of the jig-less end-effector system used in the TCTool project for picking, placing, and temporary welding and fixing fuselage’s clips and stringers.
Aerodynamic Analysis of a scaled UHBR Fan
Authors: Natale N. , Egger T. , Friedrichs J. , Russo S.
Published: February 2022

In the frame of the CA3ViAR Clean Sky 2 (Composite fan Aerodynamic, Aeroelastic, and Aeroacoustic Validation Rig), the main objective is to design a low-speed (low-transonic) fan typical of a future large aircraft UHBR engine, in terms of aerodynamic shaping as well as structural design and analysis to make sure the test article experiences aerodynamic and aeroelastic instabilities in an expected way during wind tunnel (WT) operations. Eventually, open access to all the produced models will be provided, with the objective to establish an “open test-case” for the whole European scientific community, unique in the engine fans landscape. A preliminary fan stage design is presented in this paper, details about the aerodynamic design process and the results of the CFD analysis of the stage are shown. The present UHBR fan design fulfils the initial aerodynamic requirements and represents the starting point for the structural and aeroelastic analysis within the multidisciplinary design process employed to design the final CA3ViAR fan stage.
A CFD/experimental comparative database to feed a predictive model for ground vortex characteristics
Authors: Dupuy F , Mendonça R , Costa E , Raynal S , Camenen V , Bouchet J-P , Courtine S
Published: February 2022

Most modern aircraft engines rely on the use of high Bypass Ratios (BPR) turbofans to achieve both high thrust and low specific fuel consumption. However, such configurations are prone to the formation of ground vortices during low-speed operations. This phenomenon arises under specific combinations of wind direction, velocity or inlet air speed, generating engine vibrations and leading to the suction of damaging abrasive particles. Its characterization in early design stages is crucial. In this work, a joint experimental and numerical exploration of operating conditions leading to ground vortex presence is carried out on a scaled wind tunnel configuration. Flow details are investigated for several working points obtained from a specific set of input parameters (intake speed, wind speed, ground clearance). A methodology suitable for both experimental and Computational Fluid Dynamics (CFD) works is developed to extract vortex characteristic quantities, based on a local pressure minimum and Q-criterion contours topology. A very good agreement is obtained when comparing vortex predictions stemming from CFD and experiments. This database shall be used to transpose experimental data probed outside of the nacelle to data within the nacelle using data analytics techniques, paving the way for future data driven predictive models.
An accurate RANS-based transition prediction approach (part I)
Authors: Russo S , Citro V , Natale N , Giannetti F
Published: February 2022

We present a numerical procedure to improve the performance of the classical Reynolds-Averaged Navier-Stokes approach for transitional flows by introducing a transition prediction tool in the RANS code. A black-box procedure able to estimate first the boundary layer quantities (starting from the pressure distribution) and then to compute the linear evolution of the fluctuations has been included in an existing RANS code. Thanks to the coupling to the eN method, the transition location is predicted and periodically imposed during the RANS computations. The approach proposed in this paper to predict the transition location and the laminar flow extension is based on a numerical framework based on the coupling between a high-fidelity, Reynolds–Averaged Navier–Stokes (RANS) tool and Linear Stability Equations. According to this method, boundary layer equations are written in conical formulation and the solution of RANS equations and transition onset is obtained through an eN method based on the PSE calculations. The validation of the present approach has been achieved by comparing the numerical results against the experimental data documented in the ETRIOLLA project.
Relying on Dynamically Morphing Blades to Increase the Efficiency of a Cycloidal Rotor
Authors: Huang Doudou , Gagnon Louis
Published: February 2022

The configuration of the airfoil has a significant impact on its aerodynamic performance. This paper aims to improve the aerodynamic efficiency of the cycloidal rotor system by using dynamically morphing blades. Three different camber morphing concepts (leading edge deflection, trailing edge deformation and cambered NACA profile) have been applied to a baseline 2-bladed system with rotating and pitching NACA0015 aerofoils. Then, based on these camber concepts, 2D URANS numerical simulations were conducted for blades with different morphing degrees using OpenFOAM. The simulation results verified that the flow field condition could be optimized and significantly higher thrust and efficiency could be achieved by properly tuning the morphing control. Especially, in the case of 10% trailing edge camber and 16% NACA camber, compared with baseline case, 28.1% and 43.5% higher figure of merit values were obtained, respectively. The simulation files and the results for the last rotor revolution of each case presented in this paper are available in the following dataset: https://doi.org/10.18419/darus-2191.
Numerical investigation of the impact of tubercles and wing fences on the aerodynamic behaviour of a fixed-wing, tactical Blended-Wing-Body UAV platform
Authors: Papadopoulos C , Ioannidou S , Panagiotou P , Yakinthos K
Published: February 2022

In this work, a study on the impact of passive flow control techniques on an Unmanned Aerial Vehicle (UAV) Blended Wing Body (BWB) is presented. The novel BWB layout integrates smoothly the wing to the fuselage, creating an aerodynamically superior platform. However, the lack of vertical stabilizers in the form of a tail, creates the need for aerodynamically stable and efficient wings that can withstand the spanwise flow. To that end, two passive flow control techniques are implemented in this study, namely the wing fences and the tubercles. Wing fences are vanes or airfoils attached vertically to the lifting surface and are one of the oldest flow control techniques used in aerospace applications to stop the spanwise flow. Wing fences extending from the leading edge to the trailing edge completely stop the spanwise flow. On the other hand, tubercles are sinusoidal modifications of the blade’s leading edge. This is a novel flow control technique, with the original concept inspired from the characteristic flipper of the humpback whale (Megaptera Novaeangliae). Each bump creates a set of counter-rotating vortices that acts as a virtual fence and stops the spanwise flow. The results from this comparison show that flow control techniques can offer a considerable benefit to the flying capabilities of a BWB UAV platform, by improving the lift distribution and increasing the maximum coefficient of lift.