scholarly journals Numerical Analysis of Dynamic Characteristics of Thermowell Based on Two-Way Thermo-Fluid-Solid Coupling

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Yongchao Zhang ◽  
Lilin Ding ◽  
Mei Qi ◽  
Guangxia Bei
Keyword(s):  
High Speed ◽  
Equivalent Stress ◽  
Structural Safety ◽  
Stress Cycle ◽  
Factors Affecting ◽  
Installation Angle ◽  
Safety Improvement ◽  
Improvement Measures ◽  
Main Factors ◽  
Cracking Gas

Because thermowells are prone to fatigue damage in petroleum cracking gas pipelines, in this paper, the LES method is used to simulate the flow around thermowells through two-way thermal-fluid-solid coupling, the internal causes of thermowell damage are explored, and measures for improving the thermowell safety are proposed. According to this study, when high-speed, high-temperature gas passes the thermocouple bushing, the main factors affecting the structural safety of the thermocouple bushing are the alternating stress caused by the vortex falling off, the thermal stress cycle due to the temperature gradient, and the pressure gradient impacted by the gas. Furthermore, this paper proposes improving the thermowell safety by installing the interference devices and optimizing the installation angle. The improvement measures were studied by conducting a two-way thermal fluid-structure coupling simulation. The results of this study show that after installing the interference device and optimizing the installation angle the displacement deformation of the thermowell and the equivalent stress is reduced by 57.2% and 72.1%, respectively, which indicates the safety improvement of the thermowell structure and the effectiveness of the method. The research contents of this paper can provide guidance for the installation and use of thermocouple bushing.

Analysis on the Main Factors Influencing the High-Speed Railway Passenger Flow

2014 ◽  
Vol 919-921 ◽  
pp. 1085-1090
Author(s):  
Yuan Huang ◽  
He Song ◽  
Chun Yan Jia
Keyword(s):  
High Speed ◽  
Rapid Development ◽  
Service Level ◽  
High Speed Rail ◽  
High Speed Railway ◽  
Factors Affecting ◽  
Passenger Flow ◽  
Survey Statistics ◽  
Main Factors ◽  
The Times

With the rapid development of our national economy, the fast process of city, regional passenger demand is increasing rapidly, high-speed railway emerging as the times requiring. High-speed railway has many advantages in essence and also some disadvantages. How to use its advantages, how to avoid their disadvantages, is important for the advantageous to improve the interests of the company on high speed railway transport department and railway sector, as well as the social development. Through the way of questionnaire survey, statistics and analyzes the main factors affecting the High-speed Rail passenger flow, provides more active mode of operation for the High-speed Rail department. This paper raised the urgent and realistic basis to improve the service level.

scholarly journals The Issues of Cryojet Technology Application for Rock Cutting

2018 ◽  
Vol 41 ◽  
pp. 03010
Author(s):  
Konstantin Golovin ◽  
Roman Kovalev ◽  
Andrey Kopylov
Keyword(s):  
High Speed ◽  
Cutting Tools ◽  
Experimental Studies ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Point Of View ◽  
Factors Affecting ◽  
Technology Application ◽  
High Cutting Speed ◽  
Main Factors

Water-jet technologies, based on the use of high-speed jets as cutting tools, are one of the promising directions of the destruction technologies for various materials. Jets’ capability to cut even very strong, anisotropic and composite materials, as well as their high cutting speed, that can be reached without workpiece reaction occurring on the tool, make them attractive from the point of view of their implementation as cutting tools. This paper outlines the methods of materials destruction by means of high-speed cryojet and discusses future areas of its application. The research reveals the main factors and criteria for evaluating the effectiveness of cryojet cutting. Experimental studies of the main factors affecting the cryojet cutting parameters were carried out using a bench unit. As a result of the experimental data analysis, we found the correspondences that can be used for calculating the cryojet cutting of various materials.

Research on the Velocity Attenuation Characteristics of the Fragments During High-Speed Water Entry

2018 ◽  
Author(s):  
Ya Zhang ◽  
Xiaobin Li ◽  
Siyu Li
Keyword(s):  
Aspect Ratio ◽  
High Speed ◽  
Water Entry ◽  
Entry Angle ◽  
Attenuation Coefficients ◽  
Factors Affecting ◽  
Aspect Ratios ◽  
Velocity Attenuation ◽  
Main Factors ◽  
Attenuation Characteristics

When fragments entering water at high speed, velocity attenuation coefficients of the fragments calculated by different scholars were quite different. Through theoretical analysis and numerical simulation, the velocity attenuation characteristics of the fragments with different head shapes, water entry angles and aspect ratios are studied in this paper. Numerical results show that for the fragments with different head shapes, the main factors affecting the velocity attenuation of the fragments are different. In particular, the influences of the pier’s rough effect on the velocity attenuation of the cylindrical fragments (aspect ratio ≥ 0.5) and pie fragments (aspect ratio < 0.5) are different. As the water entry angle is decreased, the fragment velocity attenuation is slowed down by the “deflection effect” of the fragment. Considering the reduction of drag coefficient, a modified velocity attenuation formula is presented for the pie fragments during high-speed water entry.

The Assessment and Reduction Approaches of the Carbon Emission in Jiangmen, China

2013 ◽  
Vol 734-737 ◽  
pp. 1852-1860 ◽  
Author(s):  
Bang Zhu Zhu ◽  
Qiu Ju Zhang
Keyword(s):  
Energy Consumption ◽  
Carbon Emissions ◽  
High Speed ◽  
Industrial Structure ◽  
Low Carbon ◽  
Carbon Policy ◽  
Factors Affecting ◽  
Main Factors ◽  
Precise Relationship ◽  
Set Up

Jiangmen in middle industrialization, in the high-speed economic development and at the same time energy consumption growing fast, are accompanied by a rise in Carbon dioxide emissions.In order to find out the main factors affecting the carbon emissions of Jiangmen, and reduce carbon emissions, this paper recommended 1990-2010 energy consumption carbon emissions of Jiangmen based on the method IPCC assessment . The ridge regression model based on the STIRPAT was set up to describe the environmental impact and the precise relationship between driving force. At last, some Suggestions were put forward : adjusting the industrial structure, changing the mode of economic growth, and the use of low carbon technology, building good real estate development of low carbon policy environment.

scholarly journals Design Evaluation and Performance Analysis of the Inside-Filling Air-Assisted High-Speed Precision Maize Seed-Metering Device

2021 ◽  
Vol 13 (10) ◽  
pp. 5483
Author(s):  
Jinwu Wang ◽  
Xin Qi ◽  
Changsu Xu ◽  
Ziming Wang ◽  
Yeming Jiang ◽  
...  
Keyword(s):  
High Speed ◽  
Parametric Design ◽  
Optimized Design ◽  
Maize Seed ◽  
Working Pressure ◽  
Factors Affecting ◽  
Poor Seed ◽  
Main Factors ◽  
And Performance ◽  
Seed Metering Device

In view of the problems of a poor seed-filling state and poor seed-cleaning effect of a precision metering device under high-speed working conditions, an inside-filling air-assisted high-speed precision maize seed-metering device was designed, fabricated, and evaluated. The overall structure and working principles of the seed-metering device are explained. Theoretical analysis and parametric design of the key parts, such as the horizontal stirring notch seed-metering plate and the wheel seed-cleaning mechanism, were carried out. The main factors that produce multiple seeding problems were studied. The forward speed (FS) and working pressure (WP) of the seed-metering device are determined as the main factors affecting the seeding performance. A quadratic orthogonal rotation combination experiment was designed. The relationship between influencing factors and performance indexes was constructed using the Design-Expert 10.0.7 software. The response surface method was used to optimize the experimental results. The results of the bench validation experiments showed that the seeding performance of the seed-metering device was excellent when the FS of the seed-metering device was 13.10 km/h and the WP of the seed-metering device was 4.75 kPa. The results of the bench comparison showed that the seeding performance of the designed seed-metering device was better than that of the conventional air-suction precision seed-metering device. This study provides theoretical and practical references for the optimized design of a pneumatic precision seed-metering device and the sustainable development of grain.

Recent Rapid Climate Changes in Antarctic and their Influence on Low Diversity Ecosystems

2010 ◽  
Vol 17 (1) ◽  
pp. 17-30 ◽  
Author(s):  
Katarzyna J. Chwedorzewska
Keyword(s):  
Environmental Variables ◽  
Climate Changes ◽  
Biological Significance ◽  
Global Changes ◽  
Factors Affecting ◽  
Low Diversity ◽  
Main Factors ◽  
The Antarctic ◽  
High Diversity ◽  
Temperature Water

ABSTRACTThe geographic position, astronomic factors (e.g. the Earth’s maximum distance from the Sun during winter), ice cover and altitude are the main factors affecting the climate of the Antarctic, which is the coldest place on Earth. Parts of Antarctica are facing the most rapid rates of anthropogenic climate change currently seen on the planet. Climate changes are occurring throughout Antarctica, affecting three major groups of environmental variables of considerable biological significance: temperature, water, UV-B radiation.Low diversity ecosystems are expected to be more vulnerable to global changes than high diversity ecosystems

Pitting Corrosion of Biomedical Titanium and Titanium Alloys: A Brief Review

2020 ◽  
Vol 16 ◽  
Author(s):  
Yu-Wei Cui ◽  
Liang-Yu Chen ◽  
Xin-Xin Liu
Keyword(s):  
Corrosion Resistance ◽  
Pitting Corrosion ◽  
Potential Temperature ◽  
Growth Stages ◽  
Factors Affecting ◽  
Ti Alloys ◽  
Pitting Corrosion Resistance ◽  
Superior Mechanical Properties ◽  
Good Biocompatibility ◽  
Main Factors

Abstract:: Thanks to their excellent corrosion resistance, superior mechanical properties and good biocompatibility, titanium (Ti) and Ti alloys are extensively applied in biomedical fields. Pitting corrosion is a critical consideration for the reliability of Ti and Ti alloys used in the human body. Therefore, this article focuses on the pitting corrosion of Ti and Ti alloys, which introduces the growth stages of pitting corrosion and its main influencing factors. Three stages, i.e. (1) breakdown of passive film, (1) metastable pitting, and (3) propagation of pitting, are roughly divided to introduce the pitting corrosion. As reviewed, corrosive environment, applied potential, temperature and alloy compositions are the main factors affecting the pitting corrosion of Ti and Ti alloys. Moreover, the pitting corrosion of different types Ti alloys are also reviewed to correlate the types of Ti alloys and the main factors of pitting corrosion. Roughly speaking, β-type Ti alloys have the best pitting corrosion resistance among the three types of Ti alloys.

scholarly journals Measuring the Efficiency of Football Clubs Using Data Envelopment Analysis: Empirical Evidence From Spanish Professional Football

SAGE Open ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 215824402198925
Author(s):  
Isidoro Guzmán-Raja ◽  
Manuela Guzmán-Raja
Keyword(s):  
Data Envelopment Analysis ◽  
High Efficiency ◽  
Sport Performance ◽  
Data Envelopment ◽  
Professional Football ◽  
Efficiency Measure ◽  
Factors Affecting ◽  
Football Clubs ◽  
Main Factors ◽  
Using Data

Professional football clubs have a special characteristic not shared by other types of companies: their sport performance (on the field) is important, in addition to their financial performance (off the field). The aim of this paper is to calculate an efficiency measure using a model that combines performance (sport and economic) based on data envelopment analysis (DEA). The main factors affecting teams’ efficiency levels are investigated using cluster analysis. For a sample of Spanish football clubs, the findings indicate that clubs achieved a relatively high efficiency level for the period studied, and that the oldest teams with the most assets had the highest efficiency scores. These results could help club managers to improve the performance of their teams.

scholarly journals Enzymatic Process for Cystoseira barbata Valorization: Ethanol Production and Additional By-Products

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 741
Author(s):  
Doinita-Roxana Cioroiu Tirpan ◽  
Ancaelena Eliza Sterpu ◽  
Claudia Irina Koncsag ◽  
Alina Georgiana Ciufu ◽  
Tănase Dobre
Keyword(s):  
Ethanol Production ◽  
Alcoholic Fermentation ◽  
Ethanol Yield ◽  
Product Yield ◽  
Liquid Ratio ◽  
Experimental Conditions ◽  
Factors Affecting ◽  
Cystoseira Barbata ◽  
Main Factors ◽  
Process Factors

The aim of this study is to evaluate the potential of dried Cystoseira barbata alga for ethanol production through alcoholic fermentation. The influence of the main factors affecting the fermentation are studied in the frame of a 23 factorial experimental plan. The main factors influencing the process are the fermentation temperature (t from 25 °C to 35 °C), the solid to liquid ratio (S/L from 0.040 g/g to 0.080 g/g), and the cellulase ratio (R from 8 U/g d.m to 16 U/g d.m.). The maximum volatile compounds yield of 0.2808 g/g d.m and ethanol yield of 0.0158 g/g d.m were favored by the following experimental conditions: process temperature of 35 °C, solid to liquid ratio of 0.0415, and enzyme ratio of 16 U/g d.m. A statistical model was used to correlate the product yield with the process factors. Additionally, 19 interesting bioactive compounds were found in the enzymatic hydrolysis and alcoholic fermentation broths which seem likely to maintain natural defence mechanisms against diseases and physical disorders.

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