scholarly journals Mathematical Modeling and Mechanism of VUV Photodegradation of H2S in the Absence of O2

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Jian-hui Xu ◽  
Bin-bin Ding ◽  
Xiao-mei Lv ◽  
Shan-hong Lan ◽  
Chao-lin Li ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Retention Time ◽  
Gas Flow ◽  
Flow Distribution ◽  
Calculation Model ◽  
Point Of View ◽  
Distribution Model ◽  
Balance Model ◽  
Photodegradation Rate ◽  
The Mathematical Model

The existence of H2S has limited the biogas energy promotion. The traditional photodegradation of H2S is usually conducted in the presence of O2, yet this is unsuitable for biogas desulfurization which should be avoided. Therefore, the ultraviolet degradation of H2S in the absence of O2 was investigated for the first time in the present study from a mathematical point of view. Light wavelength and intensity applied were 185 nm and 2.16 × 10−12 Einstein/cm2·s, respectively. Firstly, the mathematical model of H2S photodegradation was established with MATLAB software, including the gas flow distribution model and radiation model of photoreactor, kinetics model, mass balance model, and calculation model of the degradation rate. Then, the influence of the initial H2S concentration and gas retention time on the photodegradation rate were studied, for verification of the mathematical model. Results indicated that the photodegradation rate decreased with the increase in initial H2S concentration, and the maximum photodegradation rate reached 62.8% under initial concentration of 3 mg/m3. In addition, the photodegradation rate of H2S increased with the increase in retention time. The experimental results were in good accordance with the modeling results, indicating the feasibility of the mathematical model to simulate the photodegradation of H2S. Finally, the intermediate products were simulated and results showed that the main photodegradation products were found to be H2 and elemental S, and concentrations of the two main products were close and agreed well with the reaction stoichiometric coefficients. Moreover, the concentration of free radicals of H• and SH• was rather low.

scholarly journals Transformation of a mathematical model of gas flow distribution to solve the problems of gas supply system development

2020 ◽  
Vol 219 ◽  
pp. 02001
Author(s):  
Nikolay Ilkevich ◽  
Tatyana Dzyubina ◽  
Zhanna Kalinina
Keyword(s):  
Mathematical Model ◽  
Gas Flow ◽  
System Development ◽  
Flow Distribution ◽  
Supply System ◽  
Economic Environment ◽  
Gas Flows ◽  
Supply Systems ◽  
New Criteria ◽  
Gas Supply

This paper proposes taking into account new properties of gas supply systems in a mathematical model of flow distribution in comparison with the traditional formulation. The approach suggests introducing an arc coefficient, which allows for changes in the magnitude of gas flow passing along the arc, a vector of an increase in the arc throughput, and lower constraints on the gas flow along the arc. We also propose considering a new economic environment, namely, new criteria for optimizing the flow distribution and setting fictitious gas prices for consumers. These criteria enable us to take account of the priority gas supply to a definite group of consumers. As an example, the calculation of gas flows for the aggregated Unified Gas Supply System (UGSS) for 2030 is considered. This calculation takes into account the arc coefficients and the increase in the throughput of arcs.

Dynamics of Shock Waves in the Cylindrical Channel With Confusers

2009 ◽  
Vol 4 (2) ◽  
pp. 13-18
Author(s):  
Igor Anufriev ◽  
Aleksandr Golovanov ◽  
Aleksandr Tsimbalyuk ◽  
Oleg Sharypov
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Shock Wave ◽  
Shock Wave Front ◽  
Gas Flow ◽  
Cylindrical Channel ◽  
Maximal Pressure ◽  
The Mathematical Model ◽  
Forest Combustible ◽  
Gunpowder Charge

Current work covers experimental and theoretical investigation of conic confusers impact on the intensity shock wave, generated in the shock tube by explosion of gunpowder charge. For given conditions optimal geometric characteristics of the confuser, providing maximal pressure in the shock wave front, were found experimentally. The mathematical model was developed and numerical simulation of the axisymmetric shock-wave gas flow in the channel was carried out. Experimentally was shown, that the application of the optimal confuser provides significant increase of the efficiency gasdynamic effect on the combustion of forest combustible materials.

Аpplication of the mathematical model of human torso for modeling abbreval influence in wound ballistics

2020 ◽  
Vol 22 (3) ◽  
pp. 132-139
Author(s):  
A. V. Denisov ◽  
M. D. Stepanov ◽  
N. A. Haraldin ◽  
A. V. Stepanov ◽  
A. I. Borovkov ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Element Model ◽  
Mechanical Action ◽  
Calculation Model ◽  
Calculation Results ◽  
Automated Processing ◽  
Original Calculation ◽  
Using Data ◽  
The Mathematical Model ◽  
Selection Of

Abstract. In the work, a review of scientific articles on the behavior of tissues and organs of the human body under local mechanical effects on it, as well as a description of the physico-mechanical properties of biological materials. The selection of mechanical behavior for each biological material as part of a mathematical model of the human torso was carried out, its finite element model was created, validation experiments were modeled using data presented in the literature. An original calculation model of a human torso with a tuned interaction of organs with each other was developed. Contact interaction parameters are determined. The developed computational model of a human torso was verified based on data from open sources for an experiment with mechanical action by a cylindrical impactor. An algorithm for processing pressure and acceleration graphs has been implemented in order to obtain tolerance curves. A specialized modular program has been created for the automated processing of calculation results and the output of the main results. 42 numerical tests were carried out simulating the entry of a steel ball into each of 21 zones for power engineers of 40 and 80 J. According to the results of the tests for each organ, pressure and acceleration tolerance curves were obtained, animations of the behavior of organs under shock were created, visualization of the pressure field propagation in organs was obtained torso.

A Mathematical Calculation Method for Hysteresis Characteristics Analysis of Arc-Shaped Finger Seal

2020 ◽  
Author(s):  
Chun-Hua Du ◽  
Yan-Chao Zhang ◽  
Ya-Hui Cui ◽  
Shu-Na Dong ◽  
Hong-Hu Ji ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Structural Parameters ◽  
Maximum Error ◽  
Calculation Model ◽  
Correction Coefficient ◽  
Research Results ◽  
Characteristics Analysis ◽  
Leakage Characteristics ◽  
The Mathematical Model ◽  
Hysteresis Characteristics

Abstract In order to accurately predict the hysteresis characteristics of finger seal, the minimum hysteresis which can directly reflect the hysteresis of finger seal is proposed to characterize the hysteresis of finger seal. The mathematical model for calculating the minimum hysteresis of finger seal is established, the correction coefficient in the mathematical model is determined, and the mathematical model is verified by experiments. The influence of the structure and working condition parameters of finger laminates on the hysteresis characteristics is studied based on the modified calculation model, and the rule of influence is obtained in the end. Research results show that the maximum error between the leakage characteristics numerical calculation of finger seal base on modified calculation model and the experiment results is 7.64%, and the mathematical model of the minimum hysteresis is reasonable and reliable. The descending order of influence degree of structural parameters on the hysteresis characteristics of finger seal is: thickness of each finger laminate, finger repeat angle, arc radius of the finger beam arcs‘ centers, diameter of the finger base circle, width of the interstice between fingers, arc radius of finger beam. The research results provide a theoretical basis for further research on the influence of hysteresis on the finger seal leakage characteristics and the optimal design of finger seal structure.

scholarly journals A Mathematical Model Combined with Radar Data for Bell-Less Charging of a Blast Furnace

Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 239 ◽  
Author(s):  
Meng Li ◽  
Han Wei ◽  
Yao Ge ◽  
Guocai Xiao ◽  
Yaowei Yu
Keyword(s):  
Mathematical Model ◽  
Blast Furnace ◽  
Gas Flow ◽  
Radar Data ◽  
Radar System ◽  
Utilization Efficiency ◽  
Burden Distribution ◽  
Gas Utilization ◽  
Reduce Energy Consumption ◽  
The Mathematical Model

Charging directly affects the burden distribution of a blast furnace, which determines the gas distribution in the shaft of the furnace. Adjusting the charging can improve the distribution of the gas flow, increase the gas utilization efficiency of the furnace, reduce energy consumption, and prolong the life of the blast furnace. In this paper, a mathematical model of blast furnace charging was developed and applied on a steel plant in China, which includes the display of the burden profile, burden layers, descent speed of the layers, and ore/coke ratio. Furthermore, the mathematical model is developed to combine the radar data of the burden profile. The above model is currently used in Nanjing Steel as a reference for operators to adjust the charging. The model is being tested with a radar system on the blast furnace.

Research on the Influence of Furnace Structure on Copper Cooling Stave Life

2019 ◽  
Vol 38 (2019) ◽  
pp. 1-7
Author(s):  
Feng-guang Li ◽  
Jian-liang Zhang
Keyword(s):  
Service Life ◽  
Flow Velocity ◽  
Gas Flow ◽  
Flow Distribution ◽  
Distribution Model ◽  
Variational Structure ◽  
Shaft Angle ◽  
The Stability ◽  
Gas Flow Velocity ◽  
Copper Stave

AbstractIn this paper, a blast furnace gas flow distribution model with variable furnace structure was founded based on CFD (computational fluid dynamics) theory, and the gas velocity distribution near the surface of the copper staves in different areas of the BF is calculated under different conditions of variational structure parameters like Bosh angle, shaft angle, and the newly proposed “equivalent Bosh angle.” Based on the calculation, the influence rule of the BF structure on the service life of copper stave and the corresponding operation measures were obtained. The result shows that the increase of the Bosh angle and the decrease of the shaft angle will incur increasing of the gas flow velocity near the surface of the copper staves, which is harmful to the cooling stave life; the variation of the equivalent Bosh angle has a most significant influence on the cooling stave life, and the increase of the equivalent Bosh angle will cause a sharp increase of the gas flow velocity, which will damage the copper staves seriously; adopting long tuyeres and minishing the equivalent Bosh angle will reduce the washing action of the gas flow and ensure the stability of slag hanging to achieve a long service life of copper staves.

The Properties of Two-Way Cartridge Valve in Water Hydraulic through Matlab/Simulink

2012 ◽  
Vol 271-272 ◽  
pp. 1073-1076
Author(s):  
Zhen Hua Duan ◽  
Zhang Yong Wu ◽  
Qing Hui Wang ◽  
Xi Wu ◽  
Cheng Zhuo Wen
Keyword(s):  
Mathematical Model ◽  
Simulation Analysis ◽  
Point Of View ◽  
Matlab Simulink ◽  
Practical Point ◽  
Structure Characteristics ◽  
Water Hydraulic ◽  
The Mathematical Model

According to the requirements of hydraulic transmission to two-way cartridge valve, and from the practical point of view a water hydraulic two-way cartridge valve was designed. Then its structure characteristics was introduced and the mathematical model was established. The simulation analysis of the water hydraulic two-way cartridge valve has been carried out through Matlab/Simulink proving that its structure was reasonable and it had good performances.

Mathematical Modeling of Impingement of an Air Jet in a Liquid Bath

2010 ◽  
Vol 1276 ◽  
Author(s):  
J. Solórzano-López ◽  
R. Zenit ◽  
M. A. Ramírez-Argáez
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Free Surface ◽  
Gas Flow ◽  
Two Phase ◽  
Arc Furnaces ◽  
Air Jet ◽  
Image Velocimetry ◽  
Oxygen Gas ◽  
The Mathematical Model

AbstractPhysical and mathematical modeling of jet-bath interactions in electric arc furnaces represent valuable tools to obtain a better fundamental understanding of oxygen gas injection into the furnace. In this work, a 3D mathematical model is developed based on the two phase approach called Volume of Fluid (VOF), which is able to predict free surface deformations and it is coded in the commercial fluid dynamics software FLUENTTM. Validation of the mathematical model is achieved by measurements on a transparent water physical model. Measurements of free surface depressions through a high velocity camera and velocity patterns are recorded through a Particle Image Velocimetry (PIV) Technique. Flow patterns and depression geometry are identified and characterized as function of process parameters like distance from nozzle to bath, gas flow rate and impingement angle of the gas jet into the bath. A reasonable agreement is found between simulated and experimental results.

scholarly journals Theoretical-experimental static and dynamic analysis of double layered catenary

2010 ◽  
Vol 8 (2) ◽  
pp. 169-175 ◽  
Author(s):  
Ljubomir Vlajic ◽  
Dragan Kostic
Keyword(s):  
Mathematical Model ◽  
Tensile Force ◽  
Cost Effective ◽  
Calculation Model ◽  
Dynamic Tests ◽  
Building Roof ◽  
Static And Dynamic Analysis ◽  
Static And Dynamic Tests ◽  
The Stability ◽  
The Mathematical Model

The paper presents the results of static and dynamic tests of double layered catenary of the swimming pool building roof in Leskovac. By the comparison of measured and calculated values, a potential was created to correct the mathematical model, and to verify it. Only then, the calculation model for all sorts of static and dynamic load was able to simulate the realistic behavior of the structure. In this paper, the authors presented the basic recommendations in terms of what initial tensile force should be adopted in order to control the stability of such very cost-effective girders.

scholarly journals Investigation on Direct Shear and Energy Dissipation Characteristics of Iron Tailings Powder Reinforced by Polypropylene Fiber

2019 ◽  
Vol 9 (23) ◽  
pp. 5098 ◽  
Author(s):  
Jiang ◽  
Lv ◽  
Wang ◽  
Li ◽  
Wang
Keyword(s):  
Mathematical Model ◽  
Energy Dissipation ◽  
Back Propagation ◽  
Polypropylene Fiber ◽  
Interfacial Strength ◽  
Distribution Model ◽  
Direct Shear ◽  
Test Results ◽  
Effective Measure ◽  
The Mathematical Model

Resource utilization of iron tailings powder is an effective measure to reduce the dam-break risk of an iron tailings reservoir. Adding polypropylene fiber to iron tailings powder can improve its shear performance. Direct shear tests were carried out on reinforced iron tailings powder with polypropylene fiber with dosages of 0%, 0.25%, 0.5%, 0.75%, and 1%, respectively. The normal stresses during the tests were 100, 200, 300, and 400 kPa, respectively. The test results show that with the increase of polypropylene fiber dosage, the cohesive force of iron tailings powder firstly increases and then decreases gradually, and the internal friction angle firstly decreases and then increases. The back propagation (BP)neural network was used to fit the shear force (F) and shear displacement (s) of the test to obtain the F-s function relationship that satisfies the accuracy. Based on the energy dissipation theory, the direct shear energy dissipation of polypropylene-fiber-reinforced iron tailings powder was calculated. The mathematical model of energy dissipation of fiber interfacial failure was derived by the fiber distribution model. The interfacial strength parameters of polypropylene fiber were calculated based on the direct shear test data and the mathematical model of fiber interfacial energy dissipation. The test results show that the addition of polypropylene fiber from the perspective of energy dissipation can improve the shear properties of iron tailings powder.

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