Records with Subject: Numerical Methods and Statistics
Showing records 1 to 25 of 50. [First] Page: 1 2 Last
A Review of Data Mining Applications in Semiconductor Manufacturing
Pedro Espadinha-Cruz, Radu Godina, Eduardo M. G. Rodrigues
December 6, 2022 (v1)
Keywords: data mining, Fault Detection, process control, quality control, semiconductor manufacturing, yield improvement
For decades, industrial companies have been collecting and storing high amounts of data with the aim of better controlling and managing their processes. However, this vast amount of information and hidden knowledge implicit in all of this data could be utilized more efficiently. With the help of data mining techniques unknown relationships can be systematically discovered. The production of semiconductors is a highly complex process, which entails several subprocesses that employ a diverse array of equipment. The size of the semiconductors signifies a high number of units can be produced, which require huge amounts of data in order to be able to control and improve the semiconductor manufacturing process. Therefore, in this paper a structured review is made through a sample of 137 papers of the published articles in the scientific community regarding data mining applications in semiconductor manufacturing. A detailed bibliometric analysis is also made. All data mining applications are... [more]
Numerical Reconstruction of Hazardous Zones after the Release of Flammable Gases during Industrial Processes
Zdzislaw Salamonowicz, Andrzej Krauze, Malgorzata Majder-Lopatka, Anna Dmochowska, Aleksandra Piechota-Polanczyk, Andrzej Polanczyk
December 6, 2022 (v1)
The storage of large numbers of batteries and accumulators is associated with an increased risk of their ignition, which results in the release of significant amounts of hydrogen into the environment. The aim of the study was to reconstruct hazardous zones after hydrogen and liquefied propane−butane (reference gas) release for different industrial processes with the use of numerical methods. Two numerical tools (Fire Dynamics Simulator and Ansys software) were applied for the three-dimensional reconstruction of flammable gas release. Propane−butane was produced from aerosol packages, and hydrogen was produced during battery charging. Emission was analyzed in an industrial building, and both emissions were independent processes. The obtained results indicated that the hazardous zones correspond to the lower explosive level concentrations for both analyzed gasses. Moreover, the high-resolution computational fluid dynamic (CFD) model for flammable gas emissions provided noninvasive and di... [more]
A Modified Expectation Maximization Approach for Process Data Rectification
Weiwei Jiang, Rongqiang Li, Deshun Cao, Chuankun Li, Shaohui Tao
October 31, 2022 (v1)
Keywords: bias detection, data rectification, expectation maximization
Process measurements are contaminated by random and/or gross measuring errors, which degenerates performances of data-based strategies for enhancing process performances, such as online optimization and advanced control. Many approaches have been proposed to reduce the influence of measuring errors, among which expectation maximization (EM) is a novel and parameter-free one proposed recently. In this study, we studied the EM approach in detail and argued that the original EM approach is not feasible to rectify measurements contaminated by persistent biases, which is a pitfall of the original EM approach. So, we propose a modified EM approach here to circumvent this pitfall by fixing the standard deviation of random error mode. The modified EM approach was evaluated by several benchmark cases of process data rectification from literatures. The results show advantages of the proposed approach to the original EM in solving efficiency and performance of data rectification.
Prediction of Different Crude Oil Properties from FTIR Data with Statistical Methods, Deep and Shallow Neural Networks
Shahla Alizadeh, Souvik Ta, Ajay. K. Ray, Lakshminarayanan Samavedham
October 21, 2022 (v2)
Keywords: Chemometric Methods, Crude Oil Properties, Deep Neural Network, FTIR, Shallow Neural Network, Statistical Methods
In recent years, Fourier Transform InfraRed (FTIR) spectrometry has been widely used to estimate different characteristics and contents of materials in many fields. Even though numerous works have been published in this area, it has still been difficult to suggest a global method that can predict the properties of crude oils from different resources based solely on FTIR data. In this study, we compare the application of several methods in order to predict particular important properties (i.e., viscosity, density, total sulfur content, total acid number, etc.) of crude oil samples from seven different Canadian oil fields. We employed chemometric methods such as Partial Least Squares regression (PLS) and principal component regression (PCR) and compared the results to the performance of neural networks (NN) with a different number of layers. These methods were evaluated by calculating the coefficient of determination (R2) and prediction root mean squared errors (RMSE). Although less comp... [more]
Feasibility of Using VIS/NIR Spectroscopy and Multivariate Analysis for Pesticide Residue Detection in Tomatoes
Araz Soltani Nazarloo, Vali Rasooli Sharabiani, Yousef Abbaspour Gilandeh, Ebrahim Taghinezhad, Mariusz Szymanek, Maciej Sprawka
October 12, 2022 (v1)
Keywords: detection, pesticide residues, processing methods, spectroscopy, tomato
The purpose of this work was to investigate the detection of the pesticide residual (profenofos) in tomatoes by using visible/near-infrared spectroscopy. Therefore, the experiments were performed on 180 tomato samples with different percentages of profenofos pesticide (higher and lower values than the maximum residual limit (MRL)) as compared to the control (no pesticide). VIS/near infrared (NIR) spectral data from pesticide solution and non-pesticide tomato samples (used as control treatment) impregnated with different concentrations of pesticide in the range of 400 to 1050 nm were recorded by a spectrometer. For classification of tomatoes with pesticide content at lower and higher levels of MRL as healthy and unhealthy samples, we used different spectral pre-processing methods with partial least squares discriminant analysis (PLS-DA) models. The Smoothing Moving Average pre-processing method with the standard error of cross validation (SECV) = 4.2767 was selected as the best model fo... [more]
Copper Oxide Spectral Emission Detection in Chalcopyrite and Copper Concentrate Combustion
Gonzalo Reyes, Walter Diaz, Carlos Toro, Eduardo Balladares, Sergio Torres, Roberto Parra, Alejandro Vásquez
October 12, 2022 (v1)
Keywords: combustion, curve resolution, digital processing, multivariate data analysis, optical sensors, principal component analysis, signal detection, spectroscopy measurements
In this research, the spectral detection of copper oxide is reported from different combustion tests of chalcopyrite particles and copper concentrates. Combustion experiments were performed in a bench reactor. In all the tests, the radiation emitted from the sulfide particle reactions was captured in the VIS−NIR range. The obtained spectral data were processed by using the airPLS (adaptive iteratively reweighted penalized least squares) algorithm to remove their baseline, and principal component analysis (PCA) and the multivariate curve resolution method alternate least squares (MCR-ALS) methods were applied to identify the emission lines or spectral bands of copper oxides. The extracted spectral pattern is directly correlated with the emission profile reported in the literature, evidencing the potential of using spectral analysis techniques on copper sulfide combustion spectra.
Improved Statistical Pattern Analysis Monitoring for Complex Multivariate Processes Using Empirical Likelihood
Jianwen Shao, Xin Zhang, Wenhua Chen, Xiaomin Shen
July 19, 2021 (v1)
Keywords: empirical likelihood, higher-order statistics, moving window, statistical pattern analysis
This article developed an improved statistical pattern analysis (SPA) monitoring strategy for fault detection of complex multivariate processes using empirical likelihood. The technique based on statistical pattern analysis performs fault detection by inspecting change in the statistics of process variables (e.g., mean value, correlation coefficient, variance, kurtosis, etc.). It is capable of monitoring non-Gaussian or even nonlinear processes. However, the original SPA framework explicitly computes all the high-order statistics, which significantly increases the scale and dimensionality of the problem, especially in the case of complex multivariate processes. To alleviate this difficulty, we propose monitoring changes in the statistics with the same order using empirical likelihood, which is a widely used estimation method to construct confidence limits or regions for parameters with similar properties. As a result, changes in statistics of the same order can be translated into a sin... [more]
Linear Analysis of a Continuous Crystallization Process for Enantiomer Separation
Michael Mangold, Nadiia Huskova, Jonathan Gänsch, Andreas Seidel-Morgenstern
May 4, 2021 (v1)
Keywords: crystallization, distributed system, method of characteristics, population balance, process control
Continuous preferential crystallization is an innovative approach to the separation of chiral substances. The process considered in this work takes place in a gently agitated fluidized bed located in a tubular crystallizer. The feasibility of the process has been shown in previous work, but it also turned out that choosing suitable operation conditions is quite delicate. Hence, a model based process design is desirable. Existing models of the process are rather complicated and require long computational times. In this work, a simple linear dynamic model is suggested, which captures the main properties of the process. The model is distributed in space and in a property coordinate. Using the method of characteristics, a semi-analytical solution of the linear model is derived. As a challenge to the solution, there is a recycle loop in the process that causes a feedback and couples the boundary conditions at different boundaries of the computational domain. In order to deal with this, a nu... [more]
Efficient Simulation of Chromatographic Processes Using the Conservation Element/Solution Element Method
Valentin Plamenov Chernev, Alain Vande Wouwer, Achim Kienle
April 30, 2021 (v1)
Keywords: conservation element/solution element (CE/SE) method, method of lines (MOL), simulated moving bed (SMB) chromatography, Simulation, single-column chromatography
Chromatographic separation processes need efficient simulation methods, especially for nonlinear adsorption isotherms such as the Langmuir isotherms which imply the formation of concentration shocks. The focus of this paper is on the space−time conservation element/solution element (CE/SE) method. This is an explicit method for the solution of systems of partial differential equations. Numerical stability of this method is guaranteed when the Courant−Friedrichs−Lewy condition is satisfied. To investigate the accuracy and efficiency of this method, it is compared with the classical cell model, which corresponds to a first-order finite volume discretization using a method of lines approach (MOL). The evaluation is done for different models, including the ideal equilibrium model and a mass transfer model for different adsorption isotherms—including linear and nonlinear Langmuir isotherms—and for different chromatographic processes from single-column operation to more sophisticated simulat... [more]
Mathematical Modeling of Hydrodynamics in Bioreactor by Means of CFD-Based Compartment Model
Agnieszka Krychowska, Marian Kordas, Maciej Konopacki, Bartłomiej Grygorcewicz, Daniel Musik, Krzysztof Wójcik, Magdalena Jędrzejczak-Silicka, Rafał Rakoczy
April 29, 2021 (v1)
Keywords: biochemical engineering, bioreactors, mathematical modeling, Modelling
This study presents the procedure of deriving a compartmental model (CM) based on an analysis obtained from the computational fluid dynamics (CFD) model of a bioreactor. The CM is composed of two parts, a structural (that takes into account the architecture of the mathematical model), and a parametric part (which contains the extrinsic parameters of the model). The CM is composed of the branches containing the set of perfectly mixed continuous stirred-tank reactors (CSTRs) in a configuration that matches the bioreactor’s flow patterns. Therefore, this work’s main objective was to develop a mathematical model that incorporated the flow field obtained by CFD technique. The proposed mathematical model was validated by means of the experimental data in the form of the residence time distribution (RTD) measurements.
On the application of shooting method for determining semicontinuous distillation limit cycles
Thomas Adams II, Pranav Bhaswanth Madabhushi
August 17, 2020 (v1)
Keywords: Hybrid Dynamical System, Limit Cycle, Optimization, Process Design, Semicontinuous Distillation
Semicontinuous distillation is a new separation technology for distilling multicomponent mixtures.
This process was designed using design methodologies with heuristic components that evolved
over twenty years. However, the fundamental philosophy of these design methodologies, which
involves guessing, checking and then using a black-box optimization procedure to find the values
of the design variables to meet some performance criteria, has not changed. Mainly, to address the
problem of having a heuristic simulation termination criterion in the black-box optimization phase,
the single shooting method for semicontinuous distillation design was proposed in this study. We
envision that this is a first step in the transformation of the semicontinuous distillation design
process for obtaining optimal designs. We demonstrate the application of this method using two
case studies, which involve the separation of hexane, heptane and octane.
Approximate Moment Methods for Population Balance Equations in Particulate and Bioengineering Processes
Robert Dürr, Andreas Bück
June 10, 2020 (v1)
Keywords: approximate moment methods, cell-to-cell variability, heterogeneity, moment methods, particle formation, population balance equations
Population balance modeling is an established framework to describe the dynamics of particle populations in disperse phase systems found in a broad field of industrial, civil, and medical applications. The resulting population balance equations account for the dynamics of the number density distribution functions and represent (systems of) partial differential equations which require sophisticated numerical solution techniques due to the general lack of analytical solutions. A specific class of solution algorithms, so-called moment methods, is based on the reduction of complex models to a set of ordinary differential equations characterizing dynamics of integral quantities of the number density distribution function. However, in general, a closed set of moment equations is not found and one has to rely on approximate closure methods. In this contribution, a concise overview of the most prominent approximate moment methods is given.
Keller-Box Simulation for the Buongiorno Mathematical Model of Micropolar Nanofluid Flow over a Nonlinear Inclined Surface
Khuram Rafique, Muhammad Imran Anwar, Masnita Misiran, Ilyas Khan, Asiful H. Seikh, El-Sayed M. Sherif, Kottakkaran Sooppy Nisar
January 7, 2020 (v1)
Keywords: inclined surface, Keller-Box method, MHD, micropolar nanofluid, power law fluid
Brownian motion and thermophoresis diffusions are the fundamental ideas of abnormal upgrading in thermal conductivity via binary fluids (base fluid along with nanoparticles). The influence of Brownian motion and thermophoresis are focused on in the Buongiorno model. In this problem, we considered the Buongiorno model with Brownian motion and thermophoretic effects. The nonlinear ordinary differential equations are recovered from the partial differential equations of the boundary flow via compatible similarity transformations and then employed to the Keller-box scheme for numerical results. The physical quantities of our concern including skin friction, Nusselt number, and Sherwood number along with velocity, temperature and concentration profile against involved effects are demonstrated. The impacts of the involved flow parameters are drawn in graphs and tabulated forms. The inclination effect shows an inverse relation with the velocity field. Moreover, the velocity profile increases w... [more]
The Fast Potential Evaluation Method of Enhanced Oil Recovery Based on Statistical Analysis
Zhengbo Wang, Qiang Wang, Desheng Ma, Wanchun Zhao, Xiaohan Feng, Zhaoxia Liu
December 16, 2019 (v1)
Keywords: grey correlation, potential evaluation, rapid analogy, screening method, tertiary oil recovery
Based on a large number of empirical statistics of tertiary oil recovery technology in China, including polymer flooding, chemical flooding, gas flooding, in situ combustion, steam flooding, ect., 22 key reservoir parameters were filterized. Five levels of quantitative screening criteria were developed for different tertiary oil recovery methods. The mean algorithm for the downward approximation and the grey correlation theory were used in this paper to quickly select the appropriate tertiary oil recovery method for the target blocks, which provides a preferred development method for subsequent potential evaluation. In the rapid analogy evaluation method of tertiary oil recovery potential, the total similarity ratio between the target block and the example block is determined. The target block is matched with the appropriate instance block according to the total similarity ratio value, using 80% as the boundary. The ratio of the geological reserves is used to predict the oil recovery i... [more]
DynamFluid: Development and Validation of a New GUI-Based CFD Tool for the Analysis of Incompressible Non-Isothermal Flows
Héctor Redal, Jaime Carpio, Pablo A. García-Salaberri, Marcos Vera
December 11, 2019 (v1)
Keywords: benchmark problems, Boussinesq approximation, characteristic-based-split algorithm, finite element method, flow past a circular cylinder, lid-driven cavity flow, non-isothermal vertical channel
A computational fluid dynamics software (DynamFluid) based on the application of the finite element method with the characteristic-based-split algorithm is presented and validated. The software is used to numerically integrate the steady and unsteady Navier−Stokes equations for both constant-density and Boussinesq non-isothermal flows. Benchmark two-dimensional computations carried out with DynamFluid show good agreement with previous results reported in the literature. Test cases used for validation include (i) the lid-driven cavity flow, (ii) mixed convection flow in a vertical channel with asymmetric wall temperatures, (iii) unsteady incompressible flow past a circular cylinder, and (iv) steady non-isothermal flow past a circular cylinder with negligible buoyancy effects. The new software is equipped with a graphical user interface that facilitates the definition of the fluid properties, the discretization of the physical domain, the definition of the boundary conditions, and the po... [more]
An Active Power Filter Based on a Three-Level Inverter and 3D-SVPWM for Selective Harmonic and Reactive Compensation
José Luis Monroy-Morales, David Campos-Gaona, Máximo Hernández-Ángeles, Rafael Peña-Alzola, José Leonardo Guardado-Zavala
December 10, 2019 (v1)
Keywords: active power filters, neutral point clamped, selective harmonic compensation, synchronous rotatory frames
Active Power Filters (APFs) have been used for reducing waveform distortion and improving power quality. However, this function can be improved by means of a selective harmonic compensation. Since an APF has rating restrictions, it is convenient to have the option of selecting an individual or a set of particular harmonics in order to compensate and apply the total APF capabilities to eliminate these harmonics, in particular those with a greater impact on the Total Harmonic Distortion (THD). This paper presents the development of a new APF prototype based on a three-phase three-level Neutral Point Clamped (NPC) inverter with selective harmonic compensation capabilities and reactive power compensation. The selective harmonic compensation approach uses several Synchronous Rotating Frames (SRF), to detect and control individual or a set of harmonics using d and q variables. The APF includes a Three-Dimensional Space Vector Modulator (3D-SVPWM) in order to generate the compensation current... [more]
Analysis of Pressure Rise in a Closed Container Due to Internal Arcing
Peng Li, Jiangjun Ruan, Daochun Huang, Ziqing OuYang, Li Zhang, Mingyang Long, Mengting Wei
December 10, 2019 (v1)
Keywords: arc fault, arc voltage, closed container, computational fluid dynamics (CFD), pressure rise, pressure wave, switchgear
When an arc fault occurs in a medium-voltage (MV) metal enclosed switchgear, the arc heats the filling gas, resulting in a pressure rise, which may seriously damage the switchgear, the building it is contained in, or even endanger maintenance personnel. A pressure rise calculation method based on computational fluid dynamics (CFD) has been put forward in this paper. The pressure rise was calculated and the arc tests between the copper electrodes were performed in the container under different gap lengths by the current source. The results show that the calculated pressure rise agrees well with the measurement, and the relative error of the average pressure rise is about 2%. Arc volume has less effect on the pressure distribution in the container. Arc voltage Root-Mean-Square (RMS) has significant randomness with the change of arc current, and increases with the increase of gap length. The average arc voltage gradients measure at about 26, 20 and 16 V/cm when the gap lengths are 5, 10 a... [more]
An Efficient Phase-Locked Loop for Distorted Three-Phase Systems
Yijia Cao, Jiaqi Yu, Yong Xu, Yong Li, Jingrong Yu
December 10, 2019 (v1)
Keywords: distorted grid conditions, frequency adaption, Lagrange-interpolation method, SC, SGDFT
This paper proposed an efficient phase-locked loop (PLL) that features zero steady-state error of phase and frequency under voltage sag, phase jump, harmonics, DC offsets and step-and ramp-changed frequency. The PLL includes the sliding Goertzel discrete Fourier transform (SGDFT) filter-based fundamental positive sequence component separator (FPSCS), the synchronousreference-frame PLL (SRF-PLL) and the secondary control path (SCP). In order to obtain an accurate fundamental positive sequence component, SGDFT filter is introduced as it features better filtering ability at the frequencies that are integer times of fundamental frequency. Meanwhile, the second order Lagrange-interpolation method is employed to approximate the actual sampling number including both integer and fractional parts as grid frequency may deviate from the rated value. Moreover, an improved SCP with single-step comparison filtering algorithm is employed as it updates reference angular frequency according to the FPSC... [more]
Numerical Solutions of Heat Transfer for Magnetohydrodynamic Jeffery-Hamel Flow Using Spectral Homotopy Analysis Method
Asad Mahmood, Md Faisal Md Basir, Umair Ali, Mohd Shareduwan Mohd Kasihmuddin, Mohd. Asyraf Mansor
November 24, 2019 (v1)
Keywords: boundary value problems, fluid, heat transfer, Jeffery-Hamel, ordinary differential equations, partial differential equations, semi-analytical technique, spectral homotopy
This paper studies heat transfer in a two-dimensional magnetohydrodynamic viscous incompressible flow in convergent/divergent channels. The temperature profile was obtained numerically for both cases of convergent/divergent channels. It was found that the temperature profile increases with an increase in Reynold number, Prandtl number, Nusselt number and angle of the wall but decreases with an increase in Hartmann number. A relatively new numerical method called the spectral homotopy analysis method (SHAM) was used to solve the governing non-linear differential equations. The SHAM 3rd order results matched with the DTM and shooting, showing that SHAM is feasible as a technique to be used.
Application of Transformation Matrices to the Solution of Population Balance Equations
Vasyl Skorych, Nilima Das, Maksym Dosta, Jitendra Kumar, Stefan Heinrich
November 5, 2019 (v1)
Keywords: agglomeration, dynamic flowsheet simulation, milling, multidimensional distributed parameters, population balance equation, process modelling, solids, transformation matrix
The development of algorithms and methods for modelling flowsheets in the field of granular materials has a number of challenges. The difficulties are mainly related to the inhomogeneity of solid materials, requiring a description of granular materials using distributed parameters. To overcome some of these problems, an approach with transformation matrices can be used. This allows one to quantitatively describe the material transitions between different classes in a multidimensional distributed set of parameters, making it possible to properly handle dependent distributions. This contribution proposes a new method for formulating transformation matrices using population balance equations (PBE) for agglomeration and milling processes. The finite volume method for spatial discretization and the second-order Runge−Kutta method were used to obtain the complete discretized form of the PBE and to calculate the transformation matrices. The proposed method was implemented in the flowsheet mod... [more]
A Numerical Approach to Solve Volume-Based Batch Crystallization Model with Fines Dissolution Unit
Safyan Mukhtar, Muhammad Sohaib, Ishfaq Ahmad
September 23, 2019 (v1)
Keywords: orthogonal polynomials, quadrature method of moments, volume-based population balance model with fines dissolution
In this article, a numerical study of a one-dimensional, volume-based batch crystallization model (PBM) is presented that is used in numerous industries and chemical engineering sciences. A numerical approximation of the underlying model is discussed by using an alternative Quadrature Method of Moments (QMOM). Fines dissolution term is also incorporated in the governing equation for improvement of product quality and removal of undesirable particles. The moment-generating function is introduced in order to apply the QMOM. To find the quadrature abscissas, an orthogonal polynomial of degree three is derived. To verify the efficiency and accuracy of the proposed technique, two test problems are discussed. The numerical results obtained by the proposed scheme are plotted versus the analytical solutions. Thus, these findings line up well with the analytical findings.
Simulating Stochastic Populations. Direct Averaging Methods
Vu Tran, Doraiswami Ramkrishna
July 11, 2019 (v1)
Keywords: direct averaging, drug resistance, stochastic simulation, transfer
A method of directly computing the average behavior of stochastic populations is established, which obviates the time-consuming process of generating detailed sample paths. The method relies on suitably discretized time intervals in which nonlinearities are quasi-linearized to produce random variables with known expectations and variances. The pair of equations is directly solved to obtain the average behavior of the system at the end of a time interval based on its knowledge at the beginning of the interval. The sample path requirement for this process is considerably lower than that for the process over the entire simulation period. The efficiency of the method is demonstrated on the transfer of antibiotics resistance between two bacterial species which is a problem of mounting concern in fighting disease.
Discrete Element Method Model Optimization of Cylindrical Pellet Size
Jiri Rozbroj, Jiri Zegzulka, Jan Necas, Lucie Jezerska
June 10, 2019 (v1)
Keywords: DEM, friction coefficient, hopper discharge, particle image velocimetry, pellets
The DEM (Discrete Element Method) is one option for studying the kinematic behaviour of cylindrical pellets. The DEM experiments attempted to optimize the numerical model parameters that affected time and velocity as a cylindrical vessel emptied. This vessel was filled with cylindrical pellets. Optimization was accomplished by changing the coefficient of friction between particles and selecting the length accuracy grade of the sample cylindrical pellets. The initial state was a series of ten vessel-discharge experiments evaluated using PIV (Particle Image Velocimetry). The cylindrical pellet test samples were described according to their length in three accuracy grades. These cylindrical pellet length accuracy grades were subsequently used in the DEM simulations. The article discusses a comparison of the influence of the length accuracy grade of cylindrical pellets on optimal calibration of time and velocity when the cylindrical vessel is emptied. The accuracy grade of cylindrical pell... [more]
On the Boundary Conditions in a Non-Linear Dissipative Observer for Tubular Reactors
Irandi Gutierrez-Carmona, Jaime A. Moreno, H.F. Abundis-Fong
April 9, 2019 (v1)
Keywords: distributed observers, PDE, perturbation estimation, sensor position
The modal injection mechanism ensures the exponential convergence of an observer in a continuous tubular reactor in dependence with the system parameters, the sensor location, and the observer gains. In this paper, it is shown that by simple considerations in the boundary conditions, the observer convergence is improved regardless of the presence of perturbations, the sensor locations acquire a meaningful physical meaning, and by simple numerical manipulations, the perturbations in the inflow can be numerically estimated.
Numerical Models for Viscoelastic Liquid Atomization Spray
Lijuan Qian, Jianzhong Lin, Fubing Bao
February 27, 2019 (v1)
Keywords: atomization spray, numerical modeling, viscoelastic fluid
Atomization spray of non-Newtonian liquid plays a pivotal role in various engineering applications, especially for the energy utilization. To operate spray systems efficiently and well understand the effects of liquid rheological properties on the whole spray process, a comprehensive model using Euler-Lagrangian approaches was established to simulate the evolution of the atomization spray for viscoelastic liquid. Based on the Oldroyd model, the viscoelastic linear dispersion relation was introduced into the primary atomization; an extended viscoelastic version of Taylor analogy breakup (TAB) model was proposed; and the coalescence criteria was modified by rheological parameters, such as the relaxation time, the retardation time and the zero shear viscosity. The predicted results are validated with experimental data varying air-liquid mass flow ratio (ALR). Then, numerical calculations are conducted to investigate the characteristics of viscoelastic liquid atomization process. Results s... [more]
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