scholarly journals Numerical Evaluation of Probability of Harmful Impact Caused by Toxic Spill Emergencies

2019 ◽  
Vol 23 (3) ◽  
pp. 1-14 ◽  
Author(s):  
Yurii Skob ◽  
Mykhaylo Ugryumov ◽  
Eduard Granovskiy
Keyword(s):  
Mathematical Model ◽  
Three Dimensional ◽  
Automated Analysis ◽  
Probit Analysis ◽  
Relative Mass ◽  
Damage Probability ◽  
Toxic Gas ◽  
Toxic Spill ◽  
The Mathematical Model ◽  
Liquefied Gas

Abstract The purpose of the work is to assess the degree of inhalation damage of a person exposed to the toxic cloud of liquefied gas evaporation from a spill spot of various shapes. The mathematical model of liquefied gas spill evaporation which arose as a result of accidental destruction of the storage capacity and further dispersion of the gas impurity in the atmosphere surface layer was developed. The computational technology for determining the fields of conditional probability of human inhalation damage by a toxic gas based on a probit analysis is developed. The mathematical model takes into account the flow compressibility, complex terrain, three-dimensional nature of the dispersion process, and the presence of toxic liquid substance evaporation from the arbitrary spill spot with varying intensity. The model allows obtaining space-time distributions of the toxic gas relative mass concentration and inhaled toxidosis which is necessary to determine the fields of the human damage probability based on the probit analysis. For different ellipticity of the hydrogen cyanide spill elliptical spot the fields of probability of human mortal damage are obtained and the influence of spot ellipticity on the scale of the consequences of an accident of this type is analysed. The developed technology allows carrying out automated analysis and forecasting in the time and space of the damage probability of a person exposed to the toxic gas as an indicator of the safety of the technogenic object.

Numerical Modelling of Gas Explosion Overpressure Mitigation Effects

2020 ◽  
Vol 1006 ◽  
pp. 117-122
Author(s):  
Yurii Skob ◽  
Mykhaylo Ugryumov ◽  
Yuriy Dreval
Keyword(s):  
Mathematical Model ◽  
Shock Wave ◽  
Computer Technology ◽  
Solid Wall ◽  
Three Dimensional ◽  
Probit Analysis ◽  
Gas Explosion ◽  
Compression Phase ◽  
Damage Probability ◽  
Fueling Station

The main aims of this study are to assess numerically the mitigation effects caused by the solid wall installed at the fueling station in order to protect personnel from the consequences of the emergent gas explosion, evaluate the optimal location of the wall and choose the appropriate material the wall have to be made of in order not to be destructed. A three-dimensional mathematical model of an explosion of hydrogen-air cloud is used. A computer technology how to define the personnel damage probability fields on the basis of probit analysis of the explosion wave is developed. The mathematical model takes into account the complex terrain and three-dimensional non-stationary nature of the shock wave propagation process. The model allows obtaining time-spatial distribution of damaging factors (overpressure in the shock wave front and the compression phase impulse) required to determine the three-dimensional non-stationary damage probability fields based on probit analysis. The developed computer technology allows to carry out an automated analysis of the safety situation at the fueling station and to conduct a comparative analysis of the effectiveness of different types of material the protective facilities made of.

Research on cargo-loading optimization based on genetic and fuzzy integration

2021 ◽  
Vol 40 (4) ◽  
pp. 8493-8500
Author(s):  
Yanwei Du ◽  
Feng Chen ◽  
Xiaoyi Fan ◽  
Lei Zhang ◽  
Henggang Liang
Keyword(s):  
Genetic Algorithm ◽  
Mathematical Model ◽  
Three Dimensional ◽  
Distribution Center ◽  
Long Time ◽  
Low Efficiency ◽  
Decision Making Model ◽  
The Mathematical Model ◽  
Loading Scheme

With the increase of the number of loaded goods, the number of optional loading schemes will increase exponentially. It is a long time and low efficiency to determine the loading scheme with experience. Genetic algorithm is a search heuristic algorithm used to solve optimization in the field of computer science artificial intelligence. Genetic algorithm can effectively select the optimal loading scheme but unable to utilize weight and volume capacity of cargo and truck. In this paper, we propose hybrid Genetic and fuzzy logic based cargo-loading decision making model that focus on achieving maximum profit with maximum utilization of weight and volume capacity of cargo and truck. In this paper, first of all, the components of the problem of goods stowage in the distribution center are analyzed systematically, which lays the foundation for the reasonable classification of the problem of goods stowage and the establishment of the mathematical model of the problem of goods stowage. Secondly, the paper abstracts and defines the problem of goods loading in distribution center, establishes the mathematical model for the optimization of single car three-dimensional goods loading, and designs the genetic algorithm for solving the model. Finally, Matlab is used to solve the optimization model of cargo loading, and the good performance of the algorithm is verified by an example. From the performance evaluation analysis, proposed the hybrid system achieve better outcomes than the standard SA model, GA method, and TS strategy.

Simulation Investigation on Environment-Induced Pitting Corrosion on the Metal Surface

2021 ◽  
Vol 13 (5) ◽  
pp. 820-828
Author(s):  
Wei Zhang ◽  
Shengli Lv ◽  
Leijiang Yao ◽  
Xiaoyan Tong
Keyword(s):  
Mathematical Model ◽  
Pitting Corrosion ◽  
Three Dimensional ◽  
Corrosion Damage ◽  
Sudden Onset ◽  
Ion Concentration ◽  
Two Dimensional Image ◽  
Aging Aircraft ◽  
Efficient Calculation ◽  
The Mathematical Model

The prediction of corrosion damage is one of effective research methods in the safety inspection of aging aircraft structures. A mathematical model for quantifying corrosion damage is used in this paper to predict the onset of corrosion on structural surfaces exposed to aggressive environments. Based on the finite difference technique, the evolution process of local pitting corrosion on the surface of aluminum alloy in the medium is simulated, which can consider the sudden onset and the randomness of pitting corrosion. The effect of local ion concentration and oxide film damage on subsequent pitting nucleation was analyzed. Based on the efficient calculation program, the effectiveness of the mathematical model is verified by the comparison between the corrosion damage morphology and the experimental data in the literature. The results show a more widespread distribution of subsequent pits because of stronger aggressive ions are released during the life cycle of active pits and the higher diffusion coefficient of the aggressive ions. The three dimensional morphology is generated by image processing method based on the gray value of the two dimensional image of pits.

Mathematical modeling of a generic multi-profile form milling cutter

2012 ◽  
Vol 227 (5) ◽  
pp. 1036-1046 ◽  
Author(s):  
Mohammed Rajik Khan ◽  
Puneet Tandon
Keyword(s):  
Mathematical Model ◽  
Three Dimensional ◽  
Sculptured Surfaces ◽  
Three Dimensional Model ◽  
Machining Time ◽  
Milling Cutter ◽  
Machined Parts ◽  
Rotary Cutting ◽  
Three Dimensional Models ◽  
The Mathematical Model

In order to machine multiple sculptured surfaces with reduced machining time and high accuracy of the machined parts, shape design of a customised multi-point rotary cutting tool needs to be evolved. In the present work, a novel design of a generic multi-profile form milling cutter is developed for machining various multiple sculptured surfaces. This article describes in detail the mathematical model to design an accurate three-dimensional geometry of a generic multi-profile form milling cutter. Use of non-uniform rational B-spline curve(s) and sweep surfaces enables to control the shape of cutting flutes of the generic multi-profile form milling cutter. The article also discusses the methodology to develop a variety of cutters lying in the same conceptual family of multi-profile form milling cutter. To physically visualise the cutter and to show one of the downstream applications once a three-dimensional model of the cutter is available, one of the multi-profile form milling cutters is fabricated. The proposed methodology offers an intuitive high-quality mathematical model for a generic family of multi-profile form milling cutters, which is different from the traditional three-dimensional models.

Computations of Three-Dimensional Gas-Turbine Combustion Chamber Flows

1979 ◽  
Vol 101 (3) ◽  
pp. 326-336 ◽  
Author(s):  
M. A. Serag-Eldin ◽  
D. B. Spalding
Keyword(s):  
Mathematical Model ◽  
Turbulent Flows ◽  
Combustion Process ◽  
Three Dimensional ◽  
Solution Algorithm ◽  
Physical Models ◽  
Turbulence Energy ◽  
Experimental Conditions ◽  
Diffusion Controlled ◽  
The Mathematical Model

The paper presents a mathematical model for three-dimensional, swirling, recirculating, turbulent flows inside can combustors. The present model is restricted to single-phase, diffusion-controlled combustion, with negligible radiation heat-transfer; however, the introduction of other available physical models can remove these restrictions. The mathematical model comprises differential equations for: continuity, momentum, stagnation enthalpy, concentration, turbulence energy, its dissipation rate, and the mean square of concentration fluctuations. The simultaneous solution of these equations by means of a finite-difference solution algorithm yields the values of the variables at all internal grid nodes. The prediction procedure, composed of the mathematical model and its solution algorithm, is applied to predict the fields of variables within a representative can combustor; the results are compared with corresponding measurements. The predicted results give the same trends as the measured ones, but the quantitative agreement is not always acceptable; this is attributed to the combustion process not being truly diffusion-controlled for the experimental conditions investigated.

Calculations of three-dimensional viscous flow in a multiblade centrifugal fan by modelling blade forces

2003 ◽  
Vol 217 (3) ◽  
pp. 287-297 ◽  
Author(s):  
S-J Seo ◽  
K-Y Kim ◽  
S-H Kang
Keyword(s):  
Mathematical Model ◽  
Turbulent Flows ◽  
Numerical Study ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Centrifugal Fan ◽  
Complex Flows ◽  
Flow Through ◽  
Volume Method ◽  
The Mathematical Model

A numerical study is presented for Reynolds-averaged Navier-Stokes analysis of three-dimensional turbulent flows in a multiblade centrifugal fan. Present work aims at development of a relatively simple analysis method for these complex flows. A mathematical model of impeller forces is obtained from the integral analysis of the flow through the impeller. A finite volume method for discretization of governing equations and a standard k-ɛ model as turbulence closure are employed. For the validation of the mathematical model, the computational results for velocity components, static pressure, and flow angles at the exit of the impeller were compared with experimental data. The comparisons show generally good agreement, especially at higher flow coefficients.

Modeling and Simulation Analysis of the Twist Drill Conical Grinding Method Based on Pro/E Software

2010 ◽  
Vol 160-162 ◽  
pp. 1680-1684
Author(s):  
Xing Jun Gao ◽  
Qing Liu ◽  
Ping Zou ◽  
Jian Song ◽  
Ping Li
Keyword(s):  
Mathematical Model ◽  
Simulation Analysis ◽  
Three Dimensional ◽  
Fundamental Principle ◽  
Drilling Process ◽  
Twist Drill ◽  
Three Dimensional Modeling ◽  
Grinding Method ◽  
Dimensional Modeling ◽  
The Mathematical Model

The fundamental principle of the twist drill conical grinding method was introduced. The mathematical model of the twist drill was established. Mathematical model to establish drill bit is the geometric design, manufacture, cutting analysis and modeling on the basis of the drilling process. According to the twist drill grinding principle, using Pro/E the three-dimensional modeling of the twist drill was completed, and the feature of the conical grinding method was analyzed.

Updating the Mathematical Model of a Structure Using Vibration Data

2005 ◽  
Vol 11 (12) ◽  
pp. 1469-1486 ◽  
Author(s):  
Ashutosh Bagchi
Keyword(s):  
Mathematical Model ◽  
Model Updating ◽  
Three Dimensional ◽  
Field Tests ◽  
Mode Shapes ◽  
Actual Structure ◽  
Shell Elements ◽  
Vibration Data ◽  
The Difference ◽  
The Mathematical Model

Model updating is an important step for correlating the mathematical model of a structure to the real one. There are a variety of techniques available for model updating using dynamic and static measurements of the structure’s behavior. This paper concentrates on the model updating techniques using the natural frequencies or frequencies and mode shapes of a structure. An iterative technique is developed based on the matrix update method. The method hasbeenappliedtothefiniteelement models of a three span continuous steel free deck bridge located in western Canada. The finite element models of the bridge have been constructed using three-dimensional beam and facet shell elements and the models have been updated using the measured frequencies. From the study it is clear that the initial model needs to be built such that it represents the actual structure as closely as possible. The results demonstrate that the difference between the modal parameters from the model and field tests affect the quality of the model updating process.

Mathematical model of management of recirculation of motor aggregates

2017 ◽  
Vol 12 (2) ◽  
pp. 25-35 ◽  
Author(s):  
A. E. Abbasov
Keyword(s):  
Mathematical Model ◽  
Combustion Temperature ◽  
Three Dimensional ◽  
Motor Units ◽  
Toxic Substances ◽  
Model Of Management ◽  
Calculation Results ◽  
Control Dependence ◽  
Maximum Combustion Temperature ◽  
The Mathematical Model

A mathematical model of management of recirculation of motor units is developed. It is shown that the efficiency of recirculation control is achieved with a decrease in the content of toxic substances in the exhaust; Limiting the maximum combustion temperature of the fuel and the pressure in the combustion chamber; Speed control. Based on the mathematical model, an algorithm is developed for calculating the control dependence for the regulation of the position of the electromechanical recirculation valve in specialized graphic computer environments with three-dimensional and two-dimensional visualization of analysis and calculation results. Calculation of the amount of emissions of harmful substances without the developed algorithm and using the developed algorithm is carried out.

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